Pololu Robotics & Electronics
My account Comments or questions? About Pololu Contact Ordering information Distributors

Pololu Forum

I²C clock on A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge


Just a question on the I²C clock pins on the A-Star 32U4 Robot Controller SV with Raspberry Pi Bridge.

I would like to use a few I²C sensors on my project but am not certain if the listed SCL/SDA pins are available for 5v A-Star use or reserved for 3.3v Raspberry Pi communication… it would seem the latter:

PD0	3, SCL	I²C clock for Raspberry Pi communication
PD1	2, SDA	I²C data for Raspberry Pi communication

But the only other SCL/SDA referenced seem to be that actual RasPi ones at GPIO 2 and GPIO 3



The I2C lines of the ATmega 32U4 and the Raspberry Pi are connected through a level shifter on the robot controller. You can see this on page 2 of the schematic which is provided on the Resources tab of the controller’s product page. It sounds like you are not planning to use a Raspberry Pi and just want to make sure you can control some 5V I2C sensors from the ATmega 32U4. If that is the case, connecting your sensors to A-Star pins 2 and 3 (not GPIO 2 and 3) should work.



Thank you for the speedy response. Actually planning to use the Raspberry Pi for higher-functionality, but yes, hoping to control the 5V I2C sensors from the ATmega 32U4. Sounds like I can use A-Star pins 2 and 3 for that, thanks!


Just to confirm, this worked perfectly… thank you