Qwiic LED Stick - APA102C Hookup Guide
El Duderino, MAKIN-STUFF 
Troubleshooting
In this section we'll outline a few troubleshooting tips for common issues you may run into using the Qwiic LED Stick.
Software Tips
Make sure when using multiple Qwiic LED Sticks to set each board to a unique I2C address. Adjust the address either by opening the ADR jumper or using the Address Examples from the Arduino library or Python package.
Also, update to the new number of LEDs in your chain using the Change Length examples in the Arduino library and Python package. Note, the default firmware limits the maximum number of LEDs to 100.
Power Supply Tips
When using many LEDs (either multiple Qwiic LED Sticks or an additional LED strip), make sure to take into account the total current draw of your LED chain. If the total current draw is outside of the limits of your chosen controller's 3.3V regulator capacity (most SparkFun Qwiic boards have a max out of 600mA@3.3V), adjust the VLED jumper to isolate the LEDs from the rest of the circuit and use a separate voltage input via the VIN PTH pin. Connect 3.3V to 5.5V power supply capable of sourcing enough current to drive the APA102 LEDs in your string.
There is no need to add a decoupling capacitor when using an external power supply connected to VIN as the board includes a 4.7µF capacitor parallel to VIN and Ground when the VLED jumper is adjusted to use that pin to power the LEDs.
General Troubleshooting
If you need technical assistance and more information on the Qwiic LED Stick or another SparkFun product that is not working as you expected, we recommend heading on over to the SparkFun Technical Assistance page for some initial troubleshooting.
If you don't find what you need there, the SparkFun Forums are a great place to find and ask for help. If this is your first visit, you'll need to create a Forum Account to search product forums and post questions.