inter unit comm protocol

AUGUST 30, 2013 01:00 PM Assembly. Wheel. Satellite communication. Encryption. Challenge 10 Lunaro Sterlings.

Encryption Challenge. Prize = 10 Lunaro Sterlings:
decipher the message (click to get exact ciphertext):

Clue:
- source code, and executable provided,
- key (used for encryption),
- original video (used for key generation) inside this video.
- sample encryption/decryption.

Correct decryption, first, provided before 10 October, 2013 == 10 Lunaro Sterlings award (2020USD www.lunarosterling.com). Deciphered text send via e-mail to adobri@shaw.ca with subject "Encryption Challenge. Prize" and one line of deciphered text.
Available -
- source code: https://github.com/alexdobrianski/TOTAL_ENCRYPTION
- key file used in encryption - 111.tkey
- video used in key generation - in current clip.
- sample: text un-encrypted:
NOW IS THE TIME FOR ALL GOOD MEN TO COME TO THE AID OF THE PARTY
cipher text after encryption (same key 111.tkey used):
=400000000000000000000000584fba6e203321df73fe0c07f8fa9903d4d2c80ff0dd62ad87413cf289f5e1251d44766b9156d76495a022263be1b04fa8ab075fe8cc44b0e45a4ed60a2cb727=
after decryption:
NOW IS THE TIME FOR ALL GOOD MEN TO COME TO THE AID OF THE PARTY
--------
interesting article about elliptic curves : http://www.pereplet.ru/nauka/Soros/pdf/9710_138.pdf

============================================================
Приз – 10 Лунаро Стерлингов.
Первый расшифровавший сообщение до 10 октября 2013 года получает приз – 10 Лунаро Стерлингов (стоимость сегодня 2020$б стоимость 10 октября – 2030USD www.lunarosterling.com).

(кликните ниже чтобы загрузить точный шифротекст):
=65000000a000000000000000ed45a19834912670eeaace8cc71a0da73a27aa9cff844d1fdc177c1794a5a3913f4757bcfb55a2a4f dda15ca0d0c3a811f3bb68233100d3f6f1f6bda9cdcf60cada1b2f776bf74a4ac66631efe07ff2be56771d058fd9d439517c773adbf7180a3ad0835f1=
Для расшифровки предоставляется
- исходный код программы шифрования https://github.com/alexdobrianski/TOTAL_ENCRYPTION
- исполняемая программа для windows (там же)
- ключ использованный для шифрования 111.tkey (там же)
- видео файл используемый для создания ключа http://www.youtube.com/watch?v=jdMq4RzKZaU
- пример
text un-encrypted:
NOW IS THE TIME FOR ALL GOOD MEN TO COME TO THE AID OF THE PARTY
cipher text after encryption (same key 111.tkey used):
=400000000000000000000000584fba6e203321df73fe0c07f8fa9903d4d2c80ff0dd62ad87413cf289f5e1251d44766b9156d76495a022263be1b04fa8ab075fe8cc44b0e45a4ed60a2cb727=
after decryption:
NOW IS THE TIME FOR ALL GOOD MEN TO COME TO THE AID OF THE PARTY

Криптовальная программа предназначена для создания ключей шифроблокнотного типа для обеспечения защиты передаваемых данных между космическими аппаратами и наземными станциями связи, расположенными удаленно от центрального пункта управления полетом. Данный приз предназначен для проверки метода шифрования коммуникации спутниковой связи, предоставляемого Adobri Solutions Ltd на “open source” основе.

2.4 communication protocol implementation to be continued. If Implementation "as a Modem" is not good - to bad for implementation - source code was to be cut. Lunaro sterling coins database and web interface mock-up. Small program to detect noise patterns in RF. That's it for a past 1.5 week.

Модем не подходит - модем должен быть перепрограммирован. Лунаро монета - мок-ап базы даннах и веб интерфейса.

Packets transferred between microprocessors can be noisy, data can be lost. To recover from errors in header of the packet was added double unit address. Last byte in a packet can be skipped. Re transmit of the data to different micro-unit implemented on interrupt level.

Communication module do not work "like-modem" anymore. For upload data over radio-link in a packet was introduced CMD*. After CMD* rest of the packet transfer ether back to serial com (if no connection) or to the other communication module. CMD= extended to re transmit data to a another micro-unit.

GPS has a bad reception in concrete building. That creates problems in debugging GPS data processing inside main controller, - needs to take laptop and go outside.

Another SMD device able to retrieve raw GPS/GLOSNAT data was discovered - SE4110L. Without limitations on traveling speed and altitude. Device outputs data after ADC conversion. All data has to be processed in micro controller. Disadvantage - industrial temperature range.

Another alternative to GPS/GLOSSNAT was investigated but it is premature to say anything now - needs to process captured digitized data.

Внесены изменения в протокол обмена данными. Для восстановления от потерь хвостов пакетов в заголовок разрешен дублированный адрес. Закрывающий байт пакета может быть пропущен. Коммуникационные модули перестали быть модемами, для космической коммуникации это не практично. Внесена команда * - загрузки данных на подсоединенное устройство. Расширена (восстановлена из предыдущего небытия) команда = для ретрансляции пакетов.

GPS задрал - очень плохой прием в железобетонном здании. Как дурак берешь лаптоп и прешся в скверик, и вместо работы рассказываешь лекцию на тему - а что такое космос.

Появилась микросхема с полными причандалами GPS/GLOSNATA - SE4110L, до АЦП включительно, коштуе 3 бакса, хреноватый температурный режим -40+85. Достоинство - всю математику нужно считать самому и можно не платить за сертификацинную GPS (цена больше 10 штук, плюс нужно доказывать, что не был и в верблюдах не состоял) с отключенной защитой от скоростей больше 500 метров в секунду.

Другая альтернатива GPS обдумывалась, компонеты заказаны, и даже идея была опробована, - но пока все это несерьезные спекуляции - нужно обработать данные.

For proper functionality of Mission Control web site, Ground Station’s software, Ground Station’s microcontrollers, communication modules on ground station and on CubeSat, needs to synchronize clocks and timers on all devices. That process can be done in hardware. Software implementation of the process, has it is own challenges, but can bring advantages like ability to get orbit parameters.

MARCH 04, 2013 10:12 PM 2.4Ghz LNA, test's failures, and finally == worked.

Well, under Vancouver’s rain, range tests was successful – sprayed by shower antennas and prototype boards showed stable reception over 33th street up to distance 1200m. In the middle of the tests shower became pouring rain, and at the end (in 15min) equipment become totally wet (like submerged in water). Etalon BT recipient was able to pickup signal

on distances of 10m at the same time(!) LNA was able to get 0dBm signal on distance 190-160m. Thanks to the weather (loss of a signal), the last question, “how to design communication equipment for 2.4GHz?” was passed. No problem in PCB, no problem with LNA, impedance matching was The Problem.

If anyone is still reading this, then the following is an "Complete idiot's guide. Amplifier, 2.4Ghz." (case when 2.4GHz capable measuring equipment, network analyzers, oscilloscopes ant etc. pricy, totaling 20,000$ min, average== 40,000$ are unaffordable):

a) Trust impedance’s calculation – needs to try different calculators to confirm (in spreadsheet) different formulas, same input -> calculations -> same output==result. The best calculator conformed is by Dan McMahill: http://wcalc.softpedia.com/ or download from different pagehttp://publisher.brothersoft.com/dan-mcmahill.html No needs to be afraid to take integrals by Runge-Kutta formulas to confirm calculations (just kidding! – some knowledge in math is OK). People already spend a lot of time and study to get proper approximation’s formulas, they knows what they are doing, needs to use already accumulated knowledge. For impedance matching the best is Smith’s software (free version does allow using less than 6 components).

b) Calibrate capacitance meter – needs to have at hands different SMD capacitors with known values, calculation of a delta from readings takes 10 min. Needs to use the same meter’s pins for measurement.

c) Better to use SMD components - to solder the best is an infrared oven with a profile temperature’s control (todays it is on E-bay), to rework the best is a hot-air station, good tweezers is mandatory. Needs to calibrate the oven – usually it requires 10mm stand inside the tray, needs to place the electronic thermometer on the stand, insert the tray into an oven (check a max measuring range for the thermometer) and by lowering or elevating the stand, needs to get the best match for profile on LCD screen and actual temperature readings, it is taking a time (couple of hours), but oven’s calibration is mandatory. Soldering paste - for earth is Pb40%Sn60%, - for space In60%Pb40%. Soldering paste is preferable, but indium paste sometime unaffordable, alloy InPb is expensive – better to mix by weight Pb with In (lead from 3WET store == fishing equipment, and indium from e-bay). If soldering can be done by the alloy only (not by the paste) thanit is better to use a hot-air instead of an infrared oven. If soldering will done by an soldering iron than amount of the alloy can be controlled. . . (designers! Pls! do not laugh – it is my way).

d) Measure impedance of any piece of a wire pretending to be named as the coaxial cable – (on a picture connection btw PCB and the antenna actually done by a microphone wire – all designers was laughing looking on it). To measure an impedance cut piece of cable 20cm, 40 cm, 60cm, and measure the capacitance btw the central wire and the shield. Open a calculator for a "coaxial transmission line" and enter physical parameter of a coaxial cable. One parameter left unknown, it is Er (dielectric constants for insulator), change it to match the capacitance per mm(or m or ft) with already measured for the small wire. Confirm for a different wire’s size – take the medium for Er values. Then the value for the impedance in calculator will be what are you looking for.

e) In PCB calculations needs to use “coplanar waveguide with ground plane” instead of a microstrip - do not be confused with the name “microstrip” – the microstrip requires empty space btw components on PCB – usually it is unaffordable. Difference in the microstrip and the “co-we-wi-gr-pl” is 25%. Difference also in == for microstrip it require precise thickness, for waveguide it less dependable.

f) In any PCB/wire/coaxial calculation needs to use as much as possible details (connectors are separate elements, soldering pads are separate elements). No need to burry yourself under lot of details, but more details brings better result, anyway all small details will be accounted, better to do it at the beginning than at the end.

g) Do not trust what component’s supplier send,(it is not their fault – mistakes are possible during packing 100 small, same looking pieces of paper, with 0.5mmx1mm components embedded in it) measurement needs to be done before use, capacitors can be different values, resistors - different precisions, inductors- varies, instead for a capacitor you can get the resistor, that can burn active components and etc. No needs to be a paranoid, but basic component‘s checks better be done.

h) Needs to measure PCB parameters, manufacturer's spec needs to be verified – order PCB with big "testing" microstrip(or “co-we-wi-gr-pl”) and measure physical dimensions of dielectric. Measure physical dimension with PCB with plates on top and bottom and measure capacitance of a tested element. Use calculator to get range of Er – error in 1pF will give a range of a dielectric constant (Er) for a PCB.

i) Better to use two layers PCB instead of 4 (actually that is preference for ExpressPCB – for different PCB manufacturer that can be a different case) variation of Er and thickness of dielectric brings less variation for impedance for “coplanar waveguide with ground plate” in case of 2 layers board then for 4 layers.

Thanks Gregory for impedance calculation explanation. Thanks Boris for rifle sight (scope pointing), Thanks Shura for explanation of interference on transmitting antenna/diagram. Thanks Luda & Serg for catching cold under Vancouver’s winter rain.

Project will be continued for cubesat/ground station 1WT transmitter (with possibility boost power to 10 WT).

Helical antenna 138 +0J, LNA matching with patch cable 50om X*Lambda + 0.04*Lambda -> 1.2pF + 3.3nH + strip 83om (w=0.33mm d=0.36mm) 21mm

Helical Antenna 138+0J, BT input/output 50+0J matching 3.3nH patch cable X*Lambda + 0.04*Lambda.

3 cascade LNA each with 2.7nH->3.3nH->3.3nH and capacitors 1.3 on input does 100m not more.

3 cascade LNA each with 3.3nH -> 2.7nH -> 2.7nH and capacitors 1.3 on input does 100m not more.

But it allow to calculate diagram 10 degree for 3 turns, and 2degree for 16 turns, angle in direction of a end of conductor wire, it is stupid – on a school’s football field that angle was missed. That make adjustment for a test over SFU. Angle has to be tried in direction of end of a wire.

Frustration == definitely, if for LNA will not be able to find solution – everything else does not make sense – communication will be not possible on a lunar distances. The same amplifier chip working perfectly on output, but 3 in cascade works like attenuator reducing signal instead of amplifying. Attempt to switch sides (on top QE park cellular phone transmitters) did not help at all. Best suggestions to check signal with network analyzer and oscilloscope is out of reach for me. Thanks Boris for tip == needs to try connect both parts with attenuator 30dB (10k/9om) in that case it can be a brutal force = no need to go outside == all parts will be on table and soldering each of cascade for a best performance can be done faster.

Sorry no video today – even with 45min technical recording – some idiot virus crushed inventory website (chances ==2/365) , same time prime HDD crashed (chances == 1/3*365), same day change of a password request change(chances==2/365) -> retype->wrong password(chances=1/3) ->computer locked till Monday (2/7) , same day system CD disk not readable at 9PM (chances 1/10) total probability to happened in one day is: 2*2*2/365*3*365*365*3*7*10 == 1 in 3 billion – Way! And it really happened! Definitely moon is easy!

Based on calculations from www.ti.com/lit/an/swra046a/swra046a.pdf, particularly on formula from page 23 path loss = 20*log(4Pi/Lambda)+10*N*log(distance) with 1mwt transmitter and distance == 625m, value N == 2.2 matches loss of signal (2 is free space path loss, N==2.2 is close to it). Vancouver's rain does not influence on that value (on heavy rain it should be 2dB per 1km). Then attempt to work with 3.5 km and 3 cascades 10dB LNA brought fiasco. Assuming N is same 2.2 (over Burrard Inlet) gives 3 LNA combine value less then 12dB. From another hand 3 LNA somehow works, range from 625m definitely improved to 1050m (can not be measured more in the same environment, same N value). That mean losses btw LNA or LNA and switches needs to be re calculated and impedance matching should be adjusted. Do make sure that problem was in LNA instead of antennas both ground station's and cubesat's helical antennas was measured for a HPBW (Half Power BW) on a school's football field. 16 turns antenna showed 25 degree (half power on -85dBm sensitivity with distance for 1mWt is 149m) theoretical value is 26.5, and helical 3 turns showed 61 degree matched theoretical value.

Positive part of the tests – was found spot over 33th street, half block from Royal Canadian Mounted Police down hill to Oak st., top of the hill Granville st.(1100m), then again down-and-top of the hill on Vine st. or Larch st. (1000m). On 33th no cables over that distance and top 50m on Granville allows to calculate (http://www.tapr.org/ve3jf.dcc97.html) diffraction loses over single obstacle modeled as a knife edge (the loss of non-LOS path) it gives loss 32 dB. Sliding position from Larch st. allows to adjust loss in range of 3 dB. That makes that place practical to test 1WT (30bBm) transmitter (instead of 200km range LOS Baker Mnt - Grouse Mnt).

I use ExpressPCB – not best but not bad – most important for me – I get PCB manufactured on a 3 day after order.

In Australia on two antennas like for ground station with regular wi-fi distance 12km without problem – limit is horizon (or height of antenna mount) – no need for any amplifiers — I think with 20-40mwt for wi-fi distance can be 20-60 km. If to connect Bluetooth that it must work on 1 km. One man claimed that on 4 antennas together (made less fancy made then my – people used cut PVC sewage pipes) he get signal from Mars orbiter.

Schematic which I send in last tests was without regulators 3.3v – for power amplifier and for LNA. I removed them and connect 3.3v from 1amp regulator – regulators works somehow unstable – I think is just some of my mistake with capacitors – I need individual regulators for Bluetooth+PIC and separate supply for a TX and RX

R1 and R2 in power amplifier — I set 2.9V by a separate variable resistor for a voltage reference – conformed value – in original schematic was bug - fixed

С26 — my inserts — otherwise switches does not works – another bug – fixed

Then I fixed problem in control signals for TX-RX – was stupid bug in tracing.

Then was a bug in soldering on U4 (I believe this is when I baked voltage regulator 3.3 100ma)

Then was bug with sizes — capacitors size 402 (1мм х 0.5мм) and resistors 805 (2мм х 1.25мм), but on PCB I placed all sizes 402 – as a result I have to cut spaces for a bigger resistors and 10uF capacitors.

If two antennas used then stable signal is over open air - 500 -670 m. If one antenna will be behind window glass then distance reduced to 120m. If I put amplifiers, then on 500m over glass packets travels fine. Another sign that power amplifier somehow working – with antennas only (1mwt) behind trees no receptions on 100m – with amplifiers at the same spot perfect reception. Also over air 500m is definitely better reception (LED blinking only on packets used in protocol – period of blinking give rough estimates). But power amplifier should give 36 dB – am I right or not – input 1mwt – 36dB output 1Wt (current also shows 350 ma)? If it is 1Wt – than signal must be really strong – even on another side of downtown with reflection I should see reception? With 1mwt I perfectly get reflection from nearest building – with 1Wt – no reflection – only direct open air.

Run with CubeSat prototype at 3AM aroundVancouveris interesting task – all Boms are curious – usual question – Is that technology can be used to get high? At day time it is funny too – tourists

I also do not understand – first – capacitors on RF-IN RF-OUT? What sizes of traces before and after capacitors should be?

And actually what for that capacitors? – lest assume for decoupling. Then why on power amplifier it is 1.2pF and for LNA it is 2.4pF? – Frequency of a sample application for a same 2.4GHz, or this picoF just what you have today for soldering? Or this pico depend on width and length of a trace?

Does they depend on a height? No seriously – after soldering a lot of buggers on traces – trace like hatchbacks – does it require to clean buggers or make it bigger – to adjust picoF? Then thickness of PCB – how account this?

And what a hack this L1 – bloody inductor! In recommendation it is stated: “Could be removed (really?!) if -7dB(?!) return (!?) loss (??!) is acceptable (?!)” – What loss? Why loss back? — is it -8 is OK and -6 is very bad? What is ACCEPTaBLE? dB of what? And that documentation is really good – in other specs for a different chips – only pins – event horizon for a creativity – try what you like with combinations 16*15*14*… etc.

Now antenna – I soldered it on J3 over capacitor (1.2?.2.4?) – as on a picture – direct connection of a antenna to a capacitor and without capacitor – What will be proper way to soldering /connect with or without?

Then connection to a Bluetooth – today it is a coaxial 25cm (2.4Ghz length of wave) in a future Bluetooth will be on same PCB but now coaxial – question – from a point of connection length/width of a trace to capacitors should be??? 1/6 or 1/32 of wave’s length. Or nature likes different fractions?

Next – “50om /85 mil” or “50om/120mil” or something even more mysterious – “50om RFIN” “50om RFOUT” – Yes I know – it was a man with a last name Ohm – also Ommm is Tibetan song – and what? 120mil * 3 = 360 +15 = 375 = small bottle in liquor store. But how liquor store related to U=I*R?

May be needs additional amplifier? The power amplifier designed to work for wi-fi. And 1mWt is not enough to work?

Also on schematics present noise canceling QHX220IQT7. But I am fighting with difference noise - in a head mostly. I even did not soldered it.

If you understand – you help will be appreciated. My knowledge is limited in RF area - as you know.

Привет Серега!

Файлы со схематикой - http://www.adobri.com/misc/stm_bt/RF_GrSt.sch and http://www.adobri.com/misc/stm_bt/RF_GrSt.pcb с печатной платой (я также добавил эти файлы в письмо.

Если мой дурацкий провайдер на загрузиться попробуй http://www.adobri.com/misc/stm_bt/RF_GrSt.zip

Программа — ExpressPCB – такая — немного ограниченная - не дорогая — ее пользую — главное - плату получаю на второй день после заказа

Антена - http://www.shapeways.com/model/322767/2-4ghz-antena.html для граунд станции и антена на спутнике http://www.shapeways.com/model/322768/small-2-4ghz-antena-for-cubesat.html

Фотки

блутюз - http://www.nordicsemi.com/eng/content/download/2730/34105/file/nRF24L01_Product_Specification_v2_0.pdf

усилитель мощности http://ww1.microchip.com/downloads/en/DeviceDoc/S71291.pdf

низкошумящие усилители http://cache.freescale.com/files/rf_if/doc/data_sheet/MC13850.pdf

свитчи http://semicon.njr.co.jp/njr/hp/fileDownloadMedia.do?_mediaId=788

регуляторы http://www.analog.com/static/imported-files/Data_Sheets/ADP3335.pdf 500 ма

http://cds.linear.com/docs/Datasheet/1761sff.pdf 100 ма

все компоненты которые я использую в базе данных - http://174.6.165.86/dbadobri/Search.aspx

если взять просто две антены (для граунд станции) то австралийцы работают на расстоянии 12 км просто подключив на wi-fi бокс эти антены — ограничение горизонт — высота на которую поднимают антены — никакие усилители в .том случае не нужны — я думаю при 20-40мв для wi-fi должно хватить и на 20км-60 км. Если поставить блутюз то наверно будет работать на километр. В принципе чувак на счетверенную такую антену (наматывают проще меня - на канализационную трубу) принимает сигнал с марс орбитера.

схемы которые я тебе прислал в последнем варианте я выпаял регуляторы 3.3 вольтов как для усилителя мощьности так и для низкошумящего усилителя и подсоединил 3.3 вольтов 1 ампер — вел себя регулятор совсем загадочно — поэтому и выпаял

R1 and R2 в усилителе мощности — я поставил делитель и подобрал сопротивление чтобы было 2.9 вольт — подтвердил осцилографом — в оригинальной схеме была ошибка - исправил

С26 — моя вставка — иначе свитчи не работают — ошибка которую исправил

С34 — тоже - исправил ошибку

L2 — не знаю почему но поставил вместо 12nH — 8.2nH

затем исправил сигналы управляющие TX – RX – была глупая ошибка разводки

затем была ошибка пропайки на U4

затем ошибся с размерчиками — конденсаторы 402 (1мм х 0.5мм) а резисторы 805 (2мм х 1.25мм) а я все зафуговал 402 — пришлось резать перед пайкой граунд особождать место для больших резисторов.

если работать на одни антены то устойчивый прием по воздуху 500 -670 метров. Если антену занести за стекло — то ничего не принимает и не передает — когда поставил усилители — то на 500 метров проибивает через стекло — чувствуется что усилитель начал работать — еще один признак работающего усилителя — когда захожу за деревья — с услилителем достаточно направить антены — работает (а за темиже деревьями с одной антеной — ни гу-гу) — также кажеться работает улилитель низкошумящий — на расстоянии 500 метров по воздуху прием в обе стороны был более уверенный чем на чистые антены

Что я не понимаю — первое — это конденсаторы на выходе и на входе — какой длинны нужно держать трассы до и после конденсатора ?

И нахрень эти конденсатьры? Допустим для развязки — почему тогда в примере на усилитьль мощьности 1.2 пикоФарады а на низкошумящий 2.4 пикофарады — или эти пики типа, что попало под руку? Или эти пикофарады завясят от длинны х ширины ?

А от высоты не зависят? - Не я серьезно - пока все пропаяешь, на дорожки припоя - насоплишь - горбатые дорожки получаются — нужно ли эти сопли убирать или наоборот соплями регулировть пикофарады? А толщина платы - наверно на емкость тоже влияет?

На кой ляд L1 – он мне столько крови попил — в рекомендованой схеме написано — Could be removed (really?!) if -7dB(?!) return (!?) loss (??!) is acceptable (?!) - Кому ЛОСС ?почему ПОТЕРЯ ВЗАД? — а что -8 это значит нормально? или -6 это совсем плохо? DB чево? — а в каких случаях АКСЕПТАБЛЕ — и это я скажу очень грамотная документация — по другим усилителям мощьности даже ножек не приводят — паяй чо-хош — 16х15х15х... комбинаторных комбинаций — простор для творчества.

Теперь антена — я ее припаивал на J3 через конденсатор и без конденсатьра — вся плата как на снимке - тонкий провод прямо на конденсатор — Yes ! вызывает интерес — антену как по науке паять - с конденсором или беc?

Теперь подсоединение к блутюзу — сейчас это кусок японскиго коаксиального уабеля (покупаю по большому блату и только у Ли на Мэйне — у других если коаксиал дак солидный - в мизинец) длиной 25 см (длинна волны 2.4 Гига - в будущем прямо на плате буду паять блутюз, но сейчас кабелюка) вопрос - от точки припайки до конденсаторов сколько должно быть — 1/16 ? 1/32 ? - длины волны? Или природа знает другие дроби?

Дальше — везде говорят «50 ом / 85 mil” or “50om /120mil” – и умные такие фразы «50 ом выход» «50 ом на вход» — ну да! был такой дядя - Ом, жену даже может Омшей звали— из тибета— с ударением на согласную - все зудили ом-м-м - — ну и что! — 120 mil – это понимаю — на троих будет 360 — в аккурат чекушка — разливающему бонус 15 грамм - Но причем тут Ом?

Может надо предварительный услилитель сварганить от блутюза ? — всетаки усилитель мощьности для Wi-Fi. - а я его блутюзом — он бедненький поднатужится поднапружиться — а мощьности нет как нет

Там еще на схеме шумоподавитель на QHX220IQT7 – но не с тем шумом борюсь сейчас — я ее даже и не припаивал.

Как сказанно в понедельнике — не интегрируется функция типа звездной статистики - там они потрошили золотую рыбку, а затем задавались вопросом - чего она плавает - потому что ауквариум с живой водой или от осознания сказочной реальности. А у меня ни воды, не аквариума, ни мыслей, ни золотой рыбки, один ступор. Может тебе чего в голову придет

Шура

Jun 3, 2012. Well, communication protocol done. Now core BT module (cubesat/lunar modem) is capable to work in modes:

(a) 3 frequencies listening; 3 frequencies for transmit; 2 from 3 majority bits correction, bits shifting correction fix for preamble lost; synchronization of a frequency switch; lost switch frequency correction; adjust frequency on temperature drift.

(b) 1 frequency listening; 1 transmitting; the same functionality as on (a) but switching is disabled.

(c) 1 frequency listening; 3 transmitting; again same functionality; that will be main mode for a cubesat and lunar probe.

(d) 3 frequency listening; 1 transmitting; difference from (a) that it will be 3 receivers monitoring 3 frequency but transmitting goes over 1 frequency. That mode will be on ground station – to maximize probability for cubesat/lunar probe to get less noisy data;

In mode (d) instead of processing and fixing packets inside micro processor data will be tunneled to a PC and fix of data can be done locally on a more powerful desktop, or distributed to network of a computers for simultaneously error correction (for such process can be used screen savers with instant win notification for a Team Plan B supporters).

Mode (c) allow to have transfer data from cubesat/lunar probe without delay for frequency switch synchronization. That can increase data transfer from 50 kbit/sec to 70-80. Transfer date for upload is not critical. Another reserve is tweaking core module from 250kbs to 1mbs – that can give increase of a speed up to 160kbs for download data from cubesat/lunar probe, for sure such increase will require more computer power after ground station processing, and will make a sense only with good network of a “fixing” packets screen savers.

Why to invent a communication protocol? Usually 99% of a time of software development spend (lost) on following standards. Needs to do something fast == ignore standards and write from scratch (see code at http://www.adobri.com/misc/STM_BT/STM_BTCM.c).

Range test, two helical antennas, one for Cubesat prototype 3 turns http://www.shapeways.com/model/322768/small_2_4ghz_antena__for_cubesat_.html?gid=sg85851, another for a ground station with 1/3 of a turns on 3D printed antenna http://www.shapeways.com/model/322767/2-4ghz-antena.html/?material=6, transmitting power 1mWt, LNA 12dB. Normally that is a Bluetooth with a range of 10m. Testing on 25m == OK, testing on 100m == OK, but it shows that best reception will be with antennas pointing 10-15 degrees up instead of direct pointing (do not judge seriously = truly speaking designers was zero experience in antenna’s design), test over water at False Creek at Vancouver did not show good reception – looks like ground or water disturb signal, lifting tripod with transmitter and receiver manually just 1m up improve communication. Problem was corrected on a 5 block near Queen Elisabeth Park – road is strait, not much cars, hills from both side == manual holding and pointing allows to confirm communication over 450m.

That actually brings limits of a test for a ground station, the best place will be a Squamish Chief == face of cliff is around 700m and ground station has to be pointed with 45-60 degree to horizon.

Next step – amplifiers to increase power transmitting to 1Wt (in Canada allowed 4Wt), and mobile ground station assembly/functionality.

Nov 3, 2011. (translation of a prev) Ok Alex - this is a situation – the magnetometer – yesterday (all my troubles seemed so far away…) got from it accuracy 0.3 degree with capability to increase accuracy to any desired precision (first luck in last month). For sure in the magnetometer exists error related to a different measurements on different axis, but this error can be corrected by calibration, on big paper sheet I just marked angles – taped magnetometer to a wooden cube (yes, I am still playing with a wooden cubes – the are not magnetic) with long aluminum ruler, do measurement on each axis and corrections hammered directly into a (flash memory) table.

Magnetometer allowed to confirm (surprise!) latitude of aVancouver– yesterday on my uneven table 18.1 degrees matched perfectly (angle btw horizon and direction of a magnetic field’s vector).

Model of a (earth) magnetic field is simple – some cos() – sin() functions and somewhere (already forget where – in saved spreadsheet) something divided in half. Loaded yesterday (year 1977) FORTRAN’s programs by Nikolai Tzigankov. He made nice model of Earth magnetic field including influence of a solar wind on far distances from the earth. Needs to convert code to C, and adapt it to my simulator/tra-calculator. This for sure will take a time (no less a week), conversion takes no longer then hour(s), but needs to be careful with default names of integer/float variables, and mostly time spend on each line verification.

About “gyro navigation device” == “my shame” == “not finished” – one week ago understood what needs to do (or may be just foolish-ing myself that understood) – after magnetometer calibrations and implementing (magnetic) model plan-b for software == 2 second on a orbit == 16 km == vector of a magnetic field can change 0.3 degree – the same error will be in the magnetometer – for one second confirmed error is 0.3 (for 2 seconds it will be 0.15-0.2 degree ), then gyro’s readings corrected by temperature calibration, that will give: (a) gyro angles, (b) magnetometers angles, (c) difference in angles by gyro, (d) difference in angles by magnetometer. (a) + (b) flying independently against each other, but if (d) is less 0.3 on all axis then (c) is a correction’s value. On my microprocessor with 500 bytes can be perfectly implemented (c) and (d) without losing single bit – 2000 readings == 32K, dividing (like in a school) by logarithms and arctan(sqrt()) from Bradis table (school’s technology proved faster 100 times). Correction on magnetometer axis’s readings is in flash table too. I think it can be fit into 1MB (1.20$). if (not) then 1.81$ (4MB) will be suitable;

Difference in gyro implementation for rover – instead of a magnetometer it will be accelerometer – all software is the same.

Difference in gyro implementation for a ground station == zero (it is possible to use magnetometer + gyro + accelerometer to demonstrate effective trick == detection of earth rotation with a device totally not capable to so – trick will be nice but it is extra == does not worth spend time on it).

I thought that I was loosing time (and time is not my friend for today), but after careful examination Boris Chertok’s book I found that story about Luna9 has had similar problems/questions – 1 second (1/60 degree) error == 200km error on the moon, gyro, not enough power for a gyro, burned devices at tests, power station does not work, absence of telemetry out of a ground stations, orientation using sun-earth-moon, gyro does not get enough time to reach precision because of a power limitation, earth’s image was on a corner of sensor, failed deadlines, lost money and etc. One of a sample “bug” reported by Boris – after lost probe was found that one department (hundreds of people assigned to do trajectory calculation) understood “clockwise” direction totally opposite the understanding by another department. Only 14th attempt was successful.

Oct 25, 2011..Саня, докладаю - ситуевина значит такая – магнитометр == позавчера - получил от него наконецто точность в 0.3 градуса - могу теперь эту точность повышать практически до бесконечного нуля - в магнитометре конечно присутствует ошибка связанная с неравномерностью замера силы магнитного поля (полля!) по осям – но эту ошибку приготовился исправлять с помощью калибровки - на листе бумаги нарисовал углы - прискотчил прибор к детскому деревянному кубику с люминевой линейкой, замеряю по трем осям и прямиком в таблицу.

Магнитометр позволил определить широту Ванкувера по наклону магнитного поля - вчера для моего колченогого стола 18.1 градус совпали прекрасно.

Модель магнитного поля простая - синус - косинус и уж непомню где, но пополам . Загрузил вчера 1977 года фортрановские программы Николая Циганкова - он сделал достаточно точную модель магнитного поля земли - включая солнечный ветер на больших расстояниях от земли. Нужно будет переводить код в Си для моделирования - займет конечно временя - не меньше недели.

По поводу гироскопа - незакончил - неделю назад понял что нужно делать (или думаю что понял)- после проверок точности магнитометра буду с софтвером так - 2 секунды полета == 16 км - за две секунды магнитное поле уйдет на 0.3 градуса - та же точность будет у магнитометра - за одну секунду 0.3, (за две будет гдето 0.15-0.2) - т.е. порог замера. Затем гироскоп считывает по уже существующей температурной калибровке и получаю- (а) гироскоповские углы (бэ) магнетометоровские углы (цэ) гиро за 2 секунды (дэ) магнитометр за две сукунды - (а) и (бэ) плывут друг от друга как труба им на душу положит. Но если магнитометр покажет (дэ) меньше 0.3 по всем осям - значит (це) это ошибка - которую и принимаем в какчестве корректировки. На своем микрочипе в 500 байов памяти прекрасно могу сделать (цэ) и (дэ) плавющими без потери точности -2000 замеров == всего лишь 32К - деление как в школе по логарифмам - арктангенс из квадратного корня по таблице брадиса (разов 100 быстрее) - коррекция осей магнитометра в ней же - даже думаю в доллар 20 умесчюсь (1МБ), если нет - то доллар 81 пойдет (4МБ). Может придется делать температурную калибровку гироскопа по каждой оси отдельно (перпендикулярно земле).

Разница в гироскопе для луного трактора - вместо магнитометра беру акселерометр и весь софтвер тот же. Разница в гироскопе для наземной станции – никакой (моожно конечно испоользовать магнитометр для эффектного фокуса – демонстрировать вращение земли на обрудовании неспособном такое вращение детектировать – но это лишнее). Думал что теряю вермя - затем заглянул в книгу Бориса Чертока – все теже мои проблемы - гироскоп - его питание – спалили прибор при тестирвании - отсутствие телеметрии вне наземной станции - ориентировка по солнцу земле луне - гироскопу дали недостаточно времени на раскрутку, земля попала в край картинки. С четырнадцатого раза только удалось все правильно сделать.

Testing gyro was calibrated for range of temperatures, calibrating values 64K of 3x16-bit words was stored in memory. Gyro has fixed in stable position with X axe oriented to a North Star, Y to the West and Z orthogonal to X-Y forward to the Earth’s rotation axe. Drift of a zero was in a range of 5 degree per 256sec (4 minutes). Sensor was forced to max possible sensitivity (undocumented future in ITG-3200, but it gives 1/115=0.009 degree per sec – it still require 10 better sensitivity to detect earth rotation). Sensor set to 296 samples per sec (microprocessor is slow – needs to be at least 32MHz).

Zero drift was random (range from 0.01 – 5.0 degree per 4 minutes) and not depend of a derivative of a temperature. Drift was related to an orientation of a gyro, and on a previous gyro’s readings (possible that factory calibration gives drift).

Such drift is totally not acceptable for navigation, needs to eliminate error first.

On The Earth or on The Moon it is possible to do this by reading accelerometer and magnetic sensor orientation. Field of gravity is stable on the Earth and the Moon, and magneto sensor readings on the Earth are stable too (for sure to some extend). Reading from accelerometer gives absolute reading. Flying average from accelerometer can give good indication of an absence or existence of rotation and can allow to exterminate gyro’s zero drift.

Normally this is done by Kalman filter, it assuming that absolute direction is for a gravity field and based on that assumption correction to gyro’s readings (speed of a rotation) can be done. Kalman filter works good when noisy measurements done for predictable object. It is nice and well known approach, source code available for such filters including combination of 3-x accelerometer and 3-x magneto sensor. But such approach is not working on the low Earth orbit.

Hope is for a magneto sensors – first needs to calculate flying average of a 3D magnetic field orientation. If flying average during 2 sec (500 samples) is not in moving than current drift of a gyro assumed as a zero. Then time measured for a slowest changes (derivative of a orientation) gives point on a orbit when satellite crossed equator. Two times btw crossing the equator can give Keplers elements of a orbit. Checking point will be apogee and perigee – direction of a magnetic field at those two points must achieve maximum of a derivative of a direction of a magnetic field. Current position of a magnetic poles will give offset for a final Kepler position’s calculations (offsets unlikely will be known until reaching the orbit).

To fire engine at precision direction offsets of a targeting magnetic fields series of magentic sensor orientations can be downloaded to onboard microchip and verified during 15-20 minutes before engine’s ignition. This will require 8Mb data transfer from ground station 1-2 orbits prior engines firing. Less precision will require for antenna orientation to support such data transfer session. The same approach but with accelerometer can be done for orientation antenna on the Moon surface. For testing magnetic sensors approach can be used rotated magnet in shielded camera, different plane rotation gives simulation a different inclination of the orbit.

Solar panels combined in 4 groups. 4 high capacitance capacitors can be charged by any solar panel’s groups . To control such process require 16 pins for a control. Then 4 charged capacitors can give power to 4 main users of a power –

Power source for main communication amplifier controls by pins on a STM_BT microprocessor. Power source for stepper motors controls by STM_SM microprocessor. Power source for a main electronics controls by STM_MEM microprocessor.

- Initially first capacitor gives power to STM_MEM module. When it powered up it can monitor state of any 4 capacitors and switch itself power source to any of it. At this point all onboard electronics and users are switched off.

- Then at a time when it is enough power accumulated by power plant STM_MEM can go to second mode - powered backup communication module, gyro module, camera module, stepper motors/orientation module, main communication module. Each of the modules on a request from command stream from STM_MEM can initiate backup communication, make a picture, store it in STM_MEM flash memory.

- All power mode can be initiated from this moment – STM_MEM can power main processor module (80-90 mA 3.3 V). From this point of a time main processor takes care of all control. Main processor can prepare sequence of a commands and stored it back to STM_MEM module and can send a request to power down itself to save power in orientation stage and backup communication time. Main computer has to be powered on for a communication session with a ground station, session time window is 5 minutes.

In unit allocated 3 queue – One for serial input, another for I2C input, and third for output (output can be serial or I2C, but output queue is only one). Command “=XCI” force input from serial to be transmitted to unit ‘X’ with command ‘C’ over I2C line. Command “=XCc” force input from I2C to be transmitted over serial output to unit ‘X’ with command ‘C’. CMD ‘C’ can be set as ‘ ‘ (space) this will skip inserting command into a retransmission. The same correct for a ‘X’ unit address for retransmission – setting ‘ ‘ (space) will force retransmit but without sending unit address. This is convenient to retransmit data from memory storage over I2C to any unit. Also setting X =’ ‘ and C = ‘ ‘, useful to accept stream from a file on memory storage as a command stream. Stream from serial (like camera data) can be processed as a command or as not command stream. “=XCy” command take effect after finishing process of a CMD stream of ether from serial or I2C. Y == ‘i’ placed for convenience – normally unit commands can manipulate flag I2CReplyExpected and I2CReplyCMD for process responses (read operation) from I2C devices.

When received this command (from I2C or serial input) this force retransmit data over I2C to device with I2Caddr. Placing ‘>’ at the end of the command with force I2C set Stop-Start condition and read response data from I2C device.

Unit processing individual commands can insert sequence ‘<’ to work with I2C device. For doing this needs to call the same function ProcessCMD.

Function called in a serial->I2C retransmit state each time before processing bytes from input queues. Return code allows specify end conditions for retransmission. In case 0 function needs to pop queue byte by itself.

This function calls each time in a loop of processing both input queues. I2C queue has priority over serial.

Clock based on 8Mhz internal oscillator and it gives around 30 interrupts per second, seconds accuracy depend only on a stability of a internal oscillator. 29 counts of a 1/30 of a second different from last count – last count adjusted to properly set seconds. For synchronization of a timer command is:

Next MCR will be set clock to adjusted value. Setting any of day/min/hh/sec as a (space) will skip adjusting corresponded parameter.

Second timer can be used for setting any timers events – CallBkMain can be used to check firing timer conditions via Timer0Fired flag. ‘t’ prescaler timeout can set both prescaler and timeout value.

1. For retransmission serial->I2C, I2C -> serial, code for individual unit can be placed in call back functions for handling retransmissions.

2. For out of queue processing and for timer related events code for individual unit can be laced in Main Call Back function.

3. For processing stream out of CMD, code can be placed in a section before commc3.h include.

4. For processing executing prioritized CMD execution, code can be placed before commc4.h include.

5. For processing CMD normally, code can be placed after commc4.h include (till end of a function ProcessCMD).

1. Each unit can accept command from each unit. Each command can produce commands for any unit. Functionality of each unit independent from other unit. Stream of a commands traveling over serial and I2C support functionality of a vehicle and craft. Functionality of each unit for craft should be used for vehicle.

2. Protocol layers separated into a modules and can be included in individual unit’s source code by include statement (not library).

4. Debugging of a code out of simulator has to be done by LD indicators with traps to switch LED on-off. This make debugging process more complicated but force to keep all code "in-head".

5. Encouraged to use “goto” operators – this gives a real binary size savings (50%). Saving the size can give advantage to place two version of the same software in the same unit and quickly switch use of not damaged part of a binary.

6. For each individual unit must be accomplished testing serial sequence with verification expected output.

7. This is not a “good” design according modern technique software practice. All modern recommendations about software design was analyzed and accepted as not suitable for critical missions like space flight.

Memory storage unit commands (module STM_MEM.C controls OpenLog flash memory storage);

Gyro control and stepper’s motor units (for now they are the same unit, module STM_GYRO.C)

“G” – hold Gyro position X Y Z with delta offset DX, DY, DZ, in N steps with delay btw steps T

Sep 12, 2011. Protocol supporting commands (I2C multimaster, com as a loop):

"<"<I2Caddr><data>">"L<unit> - where L is a length data to read – transfer data to via I2C and wait for reply from the I2C unit

Sept 6, 2011 - Communication protocol changes. (Source code in progress). Unit must be capable to support serial and I2C multi-master protocol in different configuration. Unit interfacing “serial device” needs to relay received and transmitted data from “serial device” to another unit via I2C. Units interfacing “I2C devices” needs to relay received / transmitted data via serial. All serial units linked each other into a ring. Serial out of each unit connects to serial in of a next unit. Propagation delay (in transfer data from unit N to unit K will depend on an amount of units btw N and K. Serial communication speed - 56K/s, I2C around 200-300Kbit/s. Un-standard speed for serial can be set to 100Kbit/s, but temperature instability can reduce speed back to 56-32k. Each unit can change speed of communication. On master reset serial speed is 9600. Each unit on “power-on” transfer over serial loop sends greetings message. Traveling over the loop this message ended up at originated unit and loops functionality verified. Main processor unit can monitor traffic and detect all functional units. The same technique of traffic monitoring can be useful to avoid re-transition the same data. I.e. “Camera unit” send data to a “memory” unit at the same time main processor grab data for IKV processing and/or “24Ghz communication” unit can relay packages from “Camera unit” to “memory” with retransmitting same packages to ground station.

Packets over I2C addressed to a unit process as CMD stream inside the unit. Serial packets format:

Unit scans serial stream for matching unit’s address, relay data not addressed to unit. If inside a packet present byte equal any Unit-Address-In-System, the byte has to be escaped (by transmitter) with ESC char = “#’. Out of packed data stream also can have ESC chars to distinguish data from a packets.

3 queues: (a) for input serial stream, (b) for a output serial stream/I2C, (c) for input I2C stream. If unit require I2C communication output queue was to be emptied. The same with serial - only when output queue will be empty from I2C write stream, then serial output takes control.

<unit>~[message]<unit> - serial loop test message – unit send its own address – message will end up in originated unit. Command “~” is indication that loop is functional.

<unit>Ayyyyyxx@<unit> - request for unit to send a message “yy..yy” over I2C to unit “A”; “xx” is requests of a bytes to be read from the I2C. If message is big it sends over I2C by 10 bytes packets.

<units><speed><unit> - where speed = ‘9’(9600)| ‘1’(19200) | ‘3’(38400)| ’5’(57600)| ’0’ (max)

i.e unit <5> needs to check on unit <3. what is a clock reading – it send this stream:

Another sample: Power plant unit <4> needs to orient satellite by XXX YYY ZZZ for better energy harvesting. It send packet to a stepper motor unit <3>:

Same command can be send by main processor to adjust direction to a ground station.

Command 3+xxxyyyzzzDvxDvyDvzNNNLLLL3 can be send by backup communication to set communication session. Xxx yyy zzz is a starting orientation, and Dvx, Dvy, Dvz is a delta for a linear approximation of motion on the orbit, NNN is delay to apply delta, LLLL is amount of cycles to perform.

Sequence for commands like 3+xx..3 can be presorted in a memory unit. At the finish of command execution unit can send request to memory for another command.

i.e. Main processor unit <8> using com1 as IP dial up connection. Communication <2> unit’s TX connects to <8> unit’s RX. <8> unit’s TX connects to power plant <3> unit’s RX. At the end of the loop communication <2> unit’s RX getting the stream. Sequence send by unit <8> is :

Packets can be inside each other – for example last sample 2v23^3 can be changed to 2v3^32.

If serial stream is out of packet any unit can insert its own packets for transfer.

If unit echoing some serial packed addressed to unit N, then unit can insert another packet addressed to unit K, where K < N, otherwise it needs to wait for the end of the packet.

Execution of a CMD can be immediate after receiving command or delayed to the end of the package.

Each unit has MCLR(RA5) (h-l-h for reset), PRG(RB3,RB6,RB7) pins. Units with less pins used can be utilized to perform reset and reprogramming functions for neighbor unit. Four unused pins can reprogram / reset one unit, 5 unused pin – 2 unit, 8 can reprogram and reset 5 units. Separate programming port and reset shell be used for a main processor unit.

June 17, 2011 – IUP (Inter Unit Protocol) was re-designed from old code – now each unit has serial output connected to nearest unit’s serial input. I.e. main computer serial output connect to Transmitter’s serial input, then Transmitter’s serial output connected to Receiver’s serial input, and Receiver output connected back to main computer serial input. In passive state bytes from any units travels (looping) over entire net. Integrity of all network can be verified by any units individually. NAND gates can be used to bypass un-functional unit. RST in high state will enable transmit data btw nearest units, and pull-down resistor can be used to skip broken. Both microcontrollers (16LF88) for LDF (Laser Distance Finder) transmitter and receiver designed to be exactly the same (difference in command “wW” and “wV’ – W set W/R high, and V set ports bus into input mode). Source code: STM_LTRX.c, and for and project: STM_LTRX.mcp, STM_LTRX.mcw

================================================================================

Feb 5, 2011 – From redirection cases one remain unimplemented – in a time of receiving / transmitting packet needs to switch (by default) two remain channels in redirection state. It will be not a problem but needs to find “good” solution. Good in sense to be a small code. Also implementation of a time sensitive motor commands will require some tailoring – ether it will require special event block for TMR1/TMR0 or independent implementation using TMR2. Main function 0x3X for stepper motor implemented (by the way it takes only one processor command MOV). Now it is possible to port protocol to communication unit (modem), guidance unit, storage unit, and camera unit.

For stepper motor also needs to implement temperature sensor reading via analog/serial input.

Power station for stepper motor will include analog reading on capacitor/battery.

Jan 26 2011 – Original design was changed - 3 pins only will be available to connect network RB7,RB6,RB4 (or RB5 depended on communication serial/ I2C / serial asynchronous) speed was reduced dramatically to 8 kbit per second (data actually can be transferred twice faster 16 kbit) for now the code works with send/receive. Redirection will be later. Commands for discovery neighbourhood will be on Unit level. Code size for communication (only) 1024 bytes. Communication code will be base for another Units like Storage, Cameras, BT, Gyro, accelerometers. Left to implement Redirection (will add some size), stepper motors commands. Source code here.

Jan 11 2011 – well – it is hard to mix together coding and birth day par ty + Christ mas celebration – but it is not evening et. Interrupts on PIC16F88 are working – max # channels per unit limited to 3 (one pin has to be reserved to Serial/ I2C communication- it is pity), and serial communication over channels better be coded not using regular algorithms (check for high-low transition – delay time= ½ of a bit’s speed – delay time= bit’s speed – read bit and accumulate byte – delay –read-delay-read, etc.). Better approach (in view of saving progr memory) is to – interrupt on pin changes – then check time elapsed from first high-low transition – timing will give nice transmitting byte – and if value of a byte can be ignored (re-transmission from neighbor unit) it give processor slice of time.

Jan 7, 2011 – controller communication design. Target device PIC16F88. Design target - to get communication independent from connection’s configuration. Each unit (Stepper motors, transmitter/receiver, main on-board computer, gyro-system, power station, backup control unit, cameras) will be connected based on topology of a probe/vehicle.

Unit address is 6 bit long, total 63 addresses. Address 0x3f reserved for all units.

1000 0000 - (implemented) received message used as to identify neighbor unit – basically this is NOP operation – one unit inform its address.

1100 0000 - (implemented) received message used as to identify neighbor unit – and ask to transmit back its address In response unit send back 1000 0000 command.

1111 0011 – switch controller to SLEEP state (low power) – switching to SLEEP state makes clock unpredictable

Each unit set status “BUSY” on command execution. In "WAIT" state unit can accept new command. If unit in “BUSY” state it can be interrupted by command with interruption request.

Input buses monitored and serial input from any - read, stored internally into buffer, and then executed if unit’s address matched. If unit’s address does not match then data transferred to neighbour unit. On each session neighbour’s addresses updated. Direction chooses by closest addresses in unit’s neighbourhood.

Connection btw units can be in state “BUSY”. When data transfer finished by event

If in field <TO> high bit set ‘1’ – unit <TO> needs to interrupt execution of a command.

If in field <TO> high bit cleared ‘0’ – and unit <TO> in “BUSY” state then response from<TO> unit fill be with high bit set ‘1’. This bit will propagated to original transmitter station and transmitter stop transfer.

If on re-transmitter station all connections will be in “BUSY” state, then re-transmitter reply its address with high bit set and transmitter will stop transfer.

Samples 1. On-board computer (Unit 0x01) needs to set a clock to day 7 hour 12 min 15 sec 16 xsec 0000 in stepper motor (unit 0x14):

YYY calculates by – 1000 msc - minus transmission time – minus EEPROM read time (7 bytes) – minus store time (6 bytes) into internal clock.