This issue is commonly observed while using STM32 boards, where I2C is interrupt based. When the ‘I2C’ block is present inside an enabled subsystem, which is triggered by an ‘Interrupt’ block, the ‘I2C’ block does not read or write any data. This is because the interrupt which enables the subsystem has a higher priority than the ‘I2C’ block.
To fix this issue, you can try the following workaround:
- Add a System Initialize block in the model. When a model includes the ‘System Initialize’ block, the ‘Simulink Code Generator’ adds external code, which is specified in the ‘SystemInitialize’ function that is generated by the block. You can specify code for the code generator to add to the declaration, execution, and exit sections of the function code. Please refer to the following link to understand more about the ‘System Initialize’ block: https://www.mathworks.com/help/releases/r2024b/rtw/ref/systeminitialize.html
- Add custom code in the ‘System Initialize’ block such that it assigns a higher priority to the ‘I2C’ block, than the ‘Interrupt’ block that drives the ‘I2C’ subsystem. This will ensure that the ‘I2C’ block can perform read or write operations effectively.
The above workaround is also mentioned in the following link: https://www.mathworks.com/help/rtw/nucleo/ug/workaround-interrupt-workflow-sensors.html#mw_5d57635b-fab7-4fe7-8928-f35d11998407
I hope this helps.
