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STM32 serving as an I2C port expander

Open yrashk opened this issue 5 years ago • 3 comments

You mention STM32 being able to be used as a port expander by default (via I2C). Can you elaborate on this?

Neither the source code in stm32 nor STM32F030 datasheet provide anything of value with respect to this.

Thank you!

yrashk avatar May 27 '20 06:05 yrashk

Hello, this has to be implemented in the STM32. It will soon be added to the STM32 firmware. Basically the STM32 has to listen on the I2C port for messages send from the ESP32. I simple protocol is required to define how STM32 port pins can be read from and written to.

modtronix-com avatar May 27 '20 08:05 modtronix-com

Thank you! I guess I was confused by the wording

esp32MX-E has a secondary 32-bit ARM processor (STM32F030F4) that serves by default as an I²C port expander

(emphasis mine)

I initially assumed that your default hardware had this implemented (but I didn't find this in the source as right now the main loop of that firmware is much simpler than that).

Again, thank you! :)

yrashk avatar May 27 '20 12:05 yrashk

I'm needing the I2C port expander capability too. Any timeline for this?? Hoping this will also fix the I2C problems on your SDA/SCL pins as well??

skiizo avatar Oct 23 '20 17:10 skiizo