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Topic: "The Brick" - All In One - Arduino Platform Compatible (Read 14322 times) previous topic - next topic

frank26080115


There are 3 AtTiny84's. Each one is used for high speed counting. The reason I have seperate processors is high speed counting uses alot of processor resources once you start counting really fast pulses, and I didnt want to A) effect the result and B) bog down the main processor, which is potentially doing a ton of other things. So the AtTiny's just send the result to the main processor on request.


This sort of stuff I think would have been perfect for a CPLD or even FPGA, you can synthesize as many asynchronous counters as you can fit in one chip, and also make them do other stuff

How are you networking the ATtinys? I2C? UART (two wire per chip? addressing each chip? daisy chained? ) ? SPI?
Freelance engineer, consultant, contractor. Graduated from UW in 2013.

TonyD



There are 3 AtTiny84's. Each one is used for high speed counting. The reason I have seperate processors is high speed counting uses alot of processor resources once you start counting really fast pulses, and I didnt want to A) effect the result and B) bog down the main processor, which is potentially doing a ton of other things. So the AtTiny's just send the result to the main processor on request.


....

How are you networking the ATtinys? I2C? UART (two wire per chip? addressing each chip? daisy chained? ) ? SPI?



They talk to the main processor over SPI.
The board utilises both SPI and I2C for its various on board IC's.



WanaGo

Yeah what he said :)
SPI

Yep this no doubt would have been perfect for a FPGA etc, not quite up to that level yet but I am planning to have a play with one in the near future.

How it is currently though utilises the Arduino IDE and therefore Arduino libs etc. All of the pins utilised on the 2560 are implemented in the Arduino Mega, so in theory the IDE can natively control everything without having to do direct port manipulation, for those who dont want to have to do that etc.

scott_fx

im sorry if i missed this, but does this have the additional rx/tx serial data pins also?

WanaGo

#34
Sep 01, 2011, 11:52 pm Last Edit: Sep 02, 2011, 12:11 am by WanaGo Reason: 1
Hi
Sorry what do you mean?

This utilises all 4 serial ports on the 2560, as mentioned in the first post (the references to UART's)


chuck99z28


WanaGo

I am just assembling the first 5 at the moment, and if it works then I dont see why not.

There will be a few versions of this made at some point, this one has a lot of features and some may not be desired by everyone, so other versions can be designed if required.

Regards
James

retrolefty

So do plan on publishing a schematic, or at least more details of all the specifics of the board?

Lefty

WanaGo

Hi

Yes I plan on doing something - yet I have to prove its actually going to work first.
Still assembling - will post more details once I have the first one fully complete.

:)

James

WanaGo

#39
Sep 13, 2011, 02:24 am Last Edit: Sep 13, 2011, 02:30 am by WanaGo Reason: 1
Thought I should write a bit of an update.

Assembled the first board and had issues from the word go - power correct everywhere, but 2560 no worky. Long story short, the atMega2560 processor on that board was dead for some reason. External clock, new crystal etc, nothing seemed to get it talking. Putting it down to a 1 in a million failure - who knows. Removed the 2560 from the board and will order another chip in to replace it.

Assembled the second board, and smooth sailing so far - phew, for the most part anyway.

Tested the following things, without issues - very crude code, just to prove the hardware

2560 bootloaded and fused correctly, and USB programming working.
Relay Outputs - all 6 switch fine.
General IO - all 18 as inputs trigger as inputs no problem. Even applied 18VDC to one of the inputs, and it lived - yay.
Analog Outputs - all 4 appear to work no problem with the library found on here.
Analog Inputs - all 8 appear to work no problem too, thanks for the help RetroLefty.
Digital/PWM Outputs - all 12 appear to turn on and off, havent put much effort into making the 16 bit capable PWMs run at 16 bit yet, but thats software really.
Bluetooth - connected my Sena module and with my very crude code echoed the response to the USB so I could see whats going on, so that works. Data flowing to laptop terminal program.
SPI to atTiny84's - Got comms working with the help of Graynomad and Nick Gammon - thanks, so have the USI working in SPI mode, and can pass data between the 2560 and the atTiny's. High Speed code, as per the intension of the atTiny's, I dont have working yet. Currently trying to get that working.

Still to test:
RS232
RS485
SD Writing
RTC
EEPROM
XBEE (Dont own a XBee yet...)

So great result so far, just time consuming testing everything as Im not much of a coder, but eventually get there. On about the 4th 2am finishes with 6am start for work - so getting a bit tired, but must...push.... on.... :)

James

CrossRoads

I did the testing on my Bobuinot the same way, several little sketches that each tested a function or data path.
Crude, ugly things, but they show the hardware working, which suited my needs.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

TonyD


So great result so far, just time consuming testing everything as Im not much of a coder, but eventually get there. On about the 4th 2am finishes with 6am start for work - so getting a bit tired, but must...push.... on.... :)

Thanks for posting an update. It looks like the board testing is coming along nicely :)

We've all been there, working late into the night but in the end the results are worth the lack of sleep ;)

Graynomad

Quote
We've all been there

Amen to that :)

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

liudr

Great project! Thought maybe I can share what I've been up to around the same time frame, an ATMEGA328 powered HMI (human machine interface) or LCD keypad panel with serial interface:


16 key keypad and multi-tap. Invoke interactive menu or long messages, tones on buzzer, LED indicator and all LCD functions etc over serial. Easy to construct a menu in 1 minute :)
There is also a 20X4 version.

CrossRoads

Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

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