I2C pull-ups for ESP32 devkit + DS3231 module

[franck102]

Hi all,

I am working on a project that will combine an ESP32 devkit rev 1 and a DS3231 module like this one.

I would appreciate it if you could comment on my current thinking w.r.t pull-up resistors for the I2C SDA & SCL lines:
- the Wire library will enable the internal pullups on the ESP32, that's about 10K
- the module itself has additional 10K pullups on each line (I'll check once I receive it)
- I will add an additional 10k pull-up per line

This should result in 3.3K pull-ups per line, which should work well for that bus (3.3V, single I2C device, short lines).

Any thoughts?
Thanks!
Franck

[boarchuz]

Internals are not 10k, they're about 50k.
That still leaves you with <5k, which will be fine. If you have any issues you can always lower the I2C speed.

[franck102]

Thanks for the feedback!

Franck