Qwiic relay and I2C Doubt!

Qwiic System
1

Hello!

I am currently working on a project to control 20 separate led lights individually (each rated at 12v, 8w) using a raspberry pi, and would like to know what are the limitations I may encounter in controlling each light individually, using 5 SparkFun Qwiic Quad Relay, daisy chained.

Which will be connected to the raspberry pi using the SparkFun Qwiic HAT.

With this setup in mind, I intend to use the I2C for the addressing and remote control of each light individually.

Would there be any limitations related with the I2C because of the distance between the raspberry pi and the last relay?

Thank you,

2

Yes - most i2c connections’ max length is around 1m…so you’ll want to keep the entire bus to that or less

You will also need to disable all except one set of i2c pull ups resistors (per bus, it sounds like you intend to run one)

Lastly - you’ll need one of these https://www.sparkfun.com/products/16784 to ensure each quad relay gets its own i2c address (they have an address jumper pad, but only allows for 2 different addresses…you’ll need 4, so the mux accomplishes this for you)