Qwiic shield on Arduino Uno Wifi Rev 2 not finding Adafruit AHT20 sensor

Qwiic System
1

I just soldered the headers on my Qwiic shield with 4 qwiic connectors.

I have tried using a couple of sensors via the Qwiic connectors, but no luck.

Using the AHT20 which has Stemma QT connectors:

  • Connecting the sensor to the VIN/GND/SDA/SCL headers on the shield and the sensor works fine.

  • Connecting the sensor to one of the Qwiic connectors on the shield and it fails. An I2C address scanner shows the address as 0x60.

I know there is something very basic that I am doing wrong, but I could use enlightenment.

Thanks.

– Paul

2

DOH!

Found the solution in another topic.

The pins not going in all the way is normal, it’s caused by the USB connector being higher than normal.

We haven’t tested the Qwiic Shield on the Uno WiFi V2 but it should work with this small change:

Connect a jumper wire from A5 to SCL

Connect a jumper wire from A4 to SDA

The reason for the jumper wires is that the shield was made for the regular non WiFi Uno where the I2C pins are on A4 and A5 and the Uno WiFi V2 moves those pins over to the other side of the board. With the jumpers in place, the shield will work even though it doesn’t sit flush with the Arduino.