jhihn
Posts: 21
Joined: Wed Apr 24, 2019 3:31 am

I2C repeat start support?

Sun May 09, 2021 2:55 pm

I just got burned on a project where the slave was using repeat start variant fo the I2C protocol but the connected micro did not support it.

Can I get official word if Pi Pico supports the repeat-start variant protocol?

The slave is: https://learn.adafruit.com/using-melexi ... s?view=all
"This sensor uses a slightly non-standard type of I2C called "repeated-start". If you are not using an Arduino, make sure your microcontroller can support "repeated start I2C requests"!"

ronter
Posts: 32
Joined: Thu Nov 12, 2015 3:11 am
Location: Ottawa, Canada

Re: I2C repeat start support?

Sun May 09, 2021 5:02 pm

Section 4.3 of RP2040 Datasheet says it supports I2C Restart. I haven't actually tried it, though.

fivdi
Posts: 443
Joined: Sun Sep 23, 2012 8:09 pm
Contact: Website

Re: I2C repeat start support?

Sun May 09, 2021 5:41 pm

It should work. Take a look at the nostop parameter that can be passed to several of the I2C read and write functions. See here.

pica200
Posts: 275
Joined: Tue Aug 06, 2019 10:27 am

Re: I2C repeat start support?

Mon May 10, 2021 5:42 pm

What do they mean with its non-standard? As far as i know repeated start is perfectly fine and standard behavior for devices with registers when you change the direction.

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