I2C Loopback using bare-metal code

[maya16]

Hello All, I am trying to do a loopback test between 2 i2c's on the same board, using bare metal coding and interrupts, and the clk is HSI, 16MHz. How the i2c i configured as slave is failing to acknowledge the address sent by master i2c.
Here is a zip file containing the project.

[Andrew Neil]

You already have a thread on this - marked as solved:

I2C Loopback Test using STM32F429ZI

[maya16]

That was using HAL(API), this is register level programming.

[Andrew Neil]

So compare what happens in your bare-metal code with what happens in the (working) HAL code.

Step through both of them - see where they differ.

The chip neither knows nor cares what your code uses - it just needs to have the correct register setting, etc.

PS:

You seem to have switched both slave and master to bare-metal.

It would be more sensible to do just one at a time - otherwise you don't know whether the problem(s) are in the Master, or the Slave - or both!

https://community.st.com/t5/stm32-mcus-products/two-nucleo-boards-stm32f446re-and-stm32h723zg-communicate/m-p/737695/highlight/true#M264992

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@maya16 wrote:

slave is failing to acknowledge the address sent by master i2c.

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So is the master actually sending the correct address?

Or is the Slave not correctly recognising its address?

Or both?!