I2C Communication with QWIIC Quad Relay

Qwiic System
1

Hello,

I am having issues getting my Arduino Uno to recognize the Qwiic Quad Relay through I2C. I have soldered my wires directly to the header pins as I will not be using the qwiic connect. I am using a 5v 4A barrel jack to power the Qwiic board and have soldered the 5V jumper as directed.

Additionally, the SCK on the Qwiic board is wired to A5 on the arduino and SDA is wired t opin A4 on the arduino uno. I have confirmed the board is receiving the 3.3 volts directly at the pin. I haven’t found much support for not using the Qwiic connect and wondered if there is something I should be doing differently. Thank you.

2

Hi James,

The I2C pins broken out on the Qwiic Quad Relay tie into the same traces as the Qwiic connectors so you should have no issue manually running those wires to your Arduino. It might be a connection issue. Can you please take a few photos of the top and bottom of your Quad Relay as well as the circuit you have it in? Also, how are you checking to see if the Arduino sees the Quad Relay board on the I2C bus? Are you running a I2C scan sketch or are you using the [example code and circuit from the Hookup Guide?](https://learn.sparkfun.com/tutorials/qwiic-quad-relay-hookup-guide#example-code)