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Is it possible to use the CAN bus protocol on an STM32 without using a module?

matehyliffe
Associate II

"Hi, I'm working on an EV project. We're attempting to implement the CAN bus protocol on STM32. I'm wondering if there's a way to communicate between two STM32s using the CAN bus without using a module?"

1 ACCEPTED SOLUTION

Accepted Solutions
AScha.3
Chief

Hi,

what is the "module" here ?

If you mean a driver chip : yes, you need one on every cpu-> CAN bus; transforms rx/tx from cpu to CANH/CANL symmetrical/complement signal line..

Something like this :

AScha3_0-1709384287620.png

MCP2562  doing 3,3v cpu -> 5V standard CAN bus voltage level; and termination 120r on every end of line.

is about $ 1,50  on every cpu , and you work with real conditions, can connect to other CAN bus devices also.

If you feel a post has answered your question, please click "Accept as Solution".

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6 REPLIES 6
AScha.3
Chief

Hi,

what is the "module" here ?

If you mean a driver chip : yes, you need one on every cpu-> CAN bus; transforms rx/tx from cpu to CANH/CANL symmetrical/complement signal line..

Something like this :

AScha3_0-1709384287620.png

MCP2562  doing 3,3v cpu -> 5V standard CAN bus voltage level; and termination 120r on every end of line.

is about $ 1,50  on every cpu , and you work with real conditions, can connect to other CAN bus devices also.

If you feel a post has answered your question, please click "Accept as Solution".

The term 'module' referred to the transceiver, but as far as I understand, I need to purchase it to work on STM32. Thank you.

You need something to merge the signals. There's a low cost method with diodes and a resistor you can use to experiment at a board level.

https://www.keil.com/appnotes/files/apnt_236.pdf

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Up vote any posts that you find helpful, it shows what's working..

I was planning to buy MCP2551, but since it's not sold in my country, I will buy the SN65HVD230 module. Is it compatible with STM32F407?

I expect so, it's been used on several of the STM32 EVAL boards

Tips, Buy me a coffee, or three.. PayPal Venmo
Up vote any posts that you find helpful, it shows what's working..

I will buy the SN65HVD230 module. Is it compatible with STM32F407?

Yes indeed you can use this transceiver. It's already used in some STM32 Eval boards.

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