Talking to a Model B with a Raspberry using OBD_TX/RX

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niuh2seN
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Joined: Mon Mar 02, 2015 4:29 am

Talking to a Model B with a Raspberry using OBD_TX/RX

Post by niuh2seN »

Hello,

I would like to interface my Apdater ModeL B (3.3V) with a Raspberry. As I would like to get access to the ELM237 commands I thought about bypassing the I2C Interface and talk directly to the STM32.
Can I do this by using the OBD_RX and OBD_TX I can access via J6? I'd wire the OBD_TX to the PI's RX, OBD_RX to the Pi's TX and GND to GND, bypassing the AtMega on board.
Then set the Baudrate to 38400 and talk via the /devttyAMA0 on the PI.

Is this feasible?
stanley
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Joined: Sat Mar 01, 2014 3:15 am

Re: Talking to a Model B with a Raspberry using OBD_TX/RX

Post by stanley »

Why don't you just use the UART version?
niuh2seN
Posts: 2
Joined: Mon Mar 02, 2015 4:29 am

Re: Talking to a Model B with a Raspberry using OBD_TX/RX

Post by niuh2seN »

Valid question :) Note I could also talk to it via I2C (the Pi can do that too) and a level shifter to get the voltage from 5V to 3.3V.

The answer is: I thought about it for the fun of hacking, to see if I can bypass the AtMega and just use the more powerful Pi.
stanley
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Posts: 1018
Joined: Sat Mar 01, 2014 3:15 am

Re: Talking to a Model B with a Raspberry using OBD_TX/RX

Post by stanley »

If you add a level shifter, it will work.
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