Driver Update

Some versions of the QT Py have a new serial chip which needs a driver installed before we can install WLED. Head over to our How to Install Drivers for WCH USB to Serial Chips tutorial, and download and install the new driver.

If you have an older QT Py with CP2102 USB-to-Serial bridge, use SiLabs’ driver instead.

Install WLED

These next steps require a Web Serial-compatible browser. As of this writing, that means Google Chrome, Microsoft Edge or Opera “desktop” browsers. Other browsers (Safari, Firefox, Explorer and anything mobile) won’t work.


Plug your microcontroller into your computer with a known good USB cable. Click "Install" and select the port for your board.

Depending on the USB-to-serial bridge chip on the board, you might see one or two serial ports. On Mac, for instance, there might be both “/dev/cu.usbmodem[number]” and/dev/cu.wchusbserial[number]”. Use the “wchusbserial” one.

After successful installation, enter your WiFi network name and password when prompted. This must be a 2.4 GHz WiFi network; ESP32 does not support 5 GHz networks. If it can’t connect, then as a fallback WLED will create its own 2.4 GHz WiFi access point.

Setup & Preferences

WiFi Setup

It's a good idea to head to WiFi Setup screen and create a good URL so you can control your project from any web-enabled device. I called mine http://pico.local -- this is what I type into any web browser on my WiFi network in order to connect to my project.

LED Preferences

You need to change just a couple settings in the app to get the lights running correctly. Click the LED Preferences tab and scroll down to Hardware Setup. Enter the total number of LEDs in your strip under "Length".

Our data pin is connected to A3 (aka pin 15) on the QT Py, so make GPIO match the pin number. Also, change the IR GPIO pin to 22, which corresponds to the blue wire in the Stemma connector.

Use It

Now you can use any computer or handheld device to control your LEDs. 

Make sure your device is on the same WiFi network as your board. Navigate to your custom URL (pico.local/ for me) in a web browser. You'll see a color picker above a whole bunch of color palette choices.

Choose a color, choose an effect, and watch your lights animate and glow!

Save your favorite combinations as presets, create playlists, control the speed and intensity of the animations, and lots more. This web app is incredibly intuitive and easy to use.

On my 44-key remote, there are buttons near the bottom labeled "DIY1", "DIY2" etc. WLED will automatically assign your animation presets to these buttons so you can select your favorite presets or playlists. Simply save the presets you want to the first 6 preset slots and the buttons will pull them up. 

You will need to press the button marked "Auto" to switch to DIY mode on the remote. Press "Auto" then "DIY1" to play the preset saved to slot #1 in WLED.

Head over to the WLED wiki at to delve into all the particulars.

This guide was first published on Dec 06, 2022. It was last updated on Mar 08, 2024.

This page (WLED Software) was last updated on Mar 08, 2024.

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