I’m having difficulty Enabling I2C coms on pins 27 and 28 (SDA and SCL respectively) on a Radxa Zero 3W running Debian 11 Bullseye for the OS. I used rsetup to enable I2C4-M0 overlay and rebooted. Here is the output from the i2cdetect utility.
hank@Hank1:~$ sudo i2cdetect -y 4
[sudo] password for hank:
0 1 2 3 4 5 6 7 8 9 a b c d e f
00: – -- – -- – -- – --
10: – -- – -- – -- – -- – -- – -- – -- – --
20: – -- – -- – -- – -- – -- – -- – -- – --
30: – -- – -- – -- – -- – -- – -- – -- – --
40: 40 – -- – -- – -- – -- – -- – -- – -- –
50: – -- – -- – -- – -- – -- – -- – -- – --
60: – -- – -- – -- – -- – -- – -- – -- – --
70: 70 – -- – -- – -- –
hank@Hank1:~$
I am using I2c to communicate with a server on viam.com which provides various robotics functionality. In this case it should drive a servo through a pca9685 breakout board. The viam server complains with the following error:
9/12/2025, 9:45:31 AM error rdk.resource_manager.rdk:component:servo/head-servo resource/graph_node.go:297 resource build error: resource has unresolved dependencies not found in machine config or connected remotes: [viam-labs_periph-servo-pca9685] resource rdk:component:servo/head-servo model viam-labs:servo:pca9685.
Given the error, the problem could be in the viam configuration file, or, it could be I2C is not working properly. My question is how can I test I2C independent of the viam backend?
Thaks
Bill