ESP32 as an I2C slave

[wonde05]

I was trying to set the esp32 as an I2C slave and I could only find the Boris Lovosevic's version of micropython firmware which supports I2C slave mode.

Code: Select all

https://github.com/loboris/MicroPython_ESP32_psRAM_LoBo/wiki/i2c

The lobo's version doesn't have some features like i2s support so I spent a lot of time trying to merge lobo's version with the main micropython but I couldn't figure it out. Is it even possible to merge the two versions ?

[tepalia02]

Hi, have you checked this document too?
https://micropython-docs-esp32.readthed ... b.I2C.html

[wonde05]

Yes I did but that one is specific to the pyboard.

[tepalia02]

From this old thread, it looks like ESP-32 cannot be configured as a slave: viewtopic.php?t=10203
Let's see if anyone has anything else to offer.

[Lobo-T]

The ESP32 has hardware support for I2C slave. But it is not made available in Micropython.
You probably could get it to work by manipulating the i2c registers directly. I know someone did that for the Raspberry pico (completely different architecture, so doesn't help you).

What is your master? The easiest solution might be to switch who is master and slave.

[wonde05]

@tepalia02 thanks for your answer.
@Lobo-T I am using esp32 as master may be I'll try manipulating the i2c registers like you said or I can always use another board with slave support Its just right now I only have esp32. I hope the next micropython version includes slave support for the esp32.

[Lobo-T]

Are there any other devices on this i2c bus? If it's only the two ESP32s, have you considered just using UART between them instead?

[wonde05]

yes there are other esp32's on the bus I chose the i2c because I was trying to communicate with multiple slave esp32's and I thought that i2c would be easier to implement that.