I still haven't fully figured out lower level hardware stuff like MCUs and I'm bit confused if I'm going in right direction.
Goal is to read digital signals from OBD2 port, transmit it over internet and reconstruct same data on copy of same hardware, like "wireless middleman".
OBD2 is 16pin standard diagnostic port for cars, it has multiple protocols:
from what I've found I need only CAN transreceiver for CAN bus to step down signal.
but, rest of the pins are vendor-specific, any manufacturer can implement whatever protocol they want and I want to be able to transmit data from those pins as well but there isn't much documentation available about protocols they use, if voltages are matched MCU should be able to handle reading and writing data right? I feel like I'm missing something.
what other problems should I be expecting?
I think I'm after DSP technology, what beginner-friendly development board would you recommend that also has Wi-Fi capability?
Phalelashvili said:I think I'm after DSP technology
Why do you think that?
Usually, in this context, "DSP" = Digital Signal Processing: https://en.wikipedia.org/wiki/Digital_signal_processing - which doesn't sound at all like what you've described!
Sounds like you really need to do basic research into two separate topics:
The two are entirely unrelated, and can be tackled separately.
There are many websites discussing OBD - and open-source projects.
I would suggest that you start with something based on one of the ELM chips - which take care of all the low-level protocol stuff for you:
Maybe look at some Arduino examples ...
None of this has anything to do with ARM.
I don't know all the protocols I'll be reading and writing, so i need to read raw data without understanding what it means, transmit it and write it because other side knows how to handle the data. DSP sounded like what i was looking forI think AVR chips are too slow for this.I mentioned internet data transmission because i was looking for prototyping board that already has built-in way for internet communication.ELM is a firmware, I'm limited to it's commands.edit: i decided it would be better to use PC for internet part, communicating with device via serial connection, i just need to read all the low level data and pass it to PC.
Phalelashvili said:I don't know all the protocols I'll be reading and writing, so i need to read raw data
You said it's OBD - so that defines what protocols will be used!
OBD does have standard protocols, but there are other free pins on the connector, every car manufacturer uses those pins to implement their own protocols which aren't documented
So what you need to do is to build something that will sample the pins - like an oscilloscope or logic analyser.
Perhaps you could take a look at this:
Or maybe just get one of the cheap scope of LA boards available on ebay, etc ...
Or, perhaps, https://www.scopefun.com/
etc, etc, ...
that's a great start. thanks.
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