Let's get started with the PiicoDev® 3x RGB LED Module. In this guide, we'll connect the LED Module to our Raspberry Pi Pico and get it working with some example code to display colourful patterns.
To follow along, it's best to have:
- A Micro:bit V2
- A PiicoDev 3x RGB LED Module
- A PiicoDev Adapter for Micro:bit
- A PiicoDev Cable
- (Optional) A PiicoDev platform helps secure everything together.
We'll program with Thonny in this tutorial. If you haven't used Thonny before, check out our guide for Programming a Micro:bit with Thonny. If you prefer, you can program your Micro:bit using python.microbit.org instead (see our guide).
Contents
- Connect the RGB Module to your Micro:bit
- Download MicroPython Modules
- Example Code - Feature Demo
- Remix - Fade LEDs
- Multiple Modules (Traffic Lights)
- Reference
Connect the RGB LED Module to your Micro:bit
Plug your Micro:bit into the adapter, connect your RGB Module to the adapter via the PiicoDev cable, and finally connect your Micro:bit to your computer with a USB lead.
On the RGB Module, Ensure both ID switches are OFF, and both ID jumpers (on the back side) are unsoldered.
If you're unfamiliar with connecting PiicoDev modules, read the PiicoDev Connection Guide before proceeding.
Download MicroPython modules
We will need three files to easily control the RGB LED Module.
- Download the PiicoDev Unified Library: PiicoDev_Unified.py (right-click, "save link as").
- Download the device module: PiicoDev_RGB.py (right-click, "save link as")
- Download the example script: main.py (right-click, "save link as")
It will be best to keep these files wherever you like to keep your coding projects eg. Documents > PiicoDev
Feature Demo
Open Thonny, connect to your Micro:bit and navigate to where you stored the files from the last step. Right-click each file and select "Upload to /" to upload them to your micro:bit (Hint: View the files menu with View > Files)
Restart your micro:bit (Keyboard shortcut, Ctrl+D) and you should see your RGB LED Module run through a feature demonstration. The demos, in order, are:
- Colour individual pixels
- Clear the LEDs
- Fill the LEDs with a colour from the colour wheel, and toggle the "Power" LED
Remix - Fade LEDs
In this remix, we'll use loops to animate the LEDs, glowing them on then off. Copy the following code and paste it into main.py. Re-run main.py to observe the results.
from PiicoDev_RGB import PiicoDev_RGB
from PiicoDev_Unified import sleep_ms # Cross-platform compatible sleep function
leds = PiicoDev_RGB() # initialise the LED module with conservative default brightness
while True:
for x in range(255): # glow on
leds.fill( [x, 0, 0] ) # fill() will automatically show()
sleep_ms(2)
for x in range(255,0,-1): # glow off
leds.fill( [x, 0, 0] ) # fill() will automatically show()
sleep_ms(2)
Multiple Modules (Traffic Lights)
We can control multiple LED Modules by setting unique IDs using the onboard switches and jumpers. For this remix, leave one module with all its switches cleared (off) and set ID 1 on the second module. Make sure the solder jumpers on the rear of each module are open (unsoldered)
The following code initialises two LED modules to be controlled independently. This is done by setting the id argument of the second module to indicate the switch positions: [1,0,0,0]. For this module, only the first switch is ON, and so we put a 1 in the first position. If we closed the second switch instead, we would use id=[0,1,0,0].
To learn more about PiicoDev Modules with ID options, read our PiicoDev Connection Guide (Smart Modules).
from PiicoDev_RGB import PiicoDev_RGB
from PiicoDev_Unified import sleep_ms # Cross-platform compatible sleep function
trafficA = PiicoDev_RGB() # initialise an RGB LED module with default address (all switches OFF)
trafficB = PiicoDev_RGB(id=[1,0,0,0]) # initialise RGB LED module using switch positions (first switch ON, all others OFF)
red = [255,0,0]
amber = [225,165,0]
green = [0,255,0]
while True:
### Traffic flows one way
trafficA.clear(); trafficB.clear()
trafficA.setPixel(2, green); trafficA.show()
trafficB.setPixel(0, red); trafficB.show()
sleep_ms(2000)
### Transition
trafficA.clear();
trafficA.setPixel(1, amber); trafficA.show()
sleep_ms(1000)
### Traffic flows the other way
trafficA.clear(); trafficB.clear()
trafficA.setPixel(0, red); trafficA.show()
trafficB.setPixel(2, green); trafficB.show()
sleep_ms(2000)
### Transition
trafficB.clear();
trafficB.setPixel(1, amber); trafficB.show()
sleep_ms(1000)
Reference
setPixel
setPixel(n, colour) will set led # n to the RGB colour colour = [r,g,b] where r,g,b are 0-255
Once the pixels are set with setPixel(), the new values must be pushed to the physical LEDs with show().
show
Updates the physical LEDs with data set by eg. setPixel().
clear
Blanks all the RGB LEDs. It is not necessary to call show() after calling clear().
setBrightness
setBrightness(x) controls the maximum brightness of the RGB LEDs, where x may be between 0-255. This function is useful to avoid being dazzled by the bright LEDs, or to keep current consumption low.
fill
fill(colour) will fill all RGB LEDs with the colour specified by the RGB list colour. Automatically updates the LEDs by calling show()
wheel
wheel(i) returns an RGB colour list [r,g,b] colour from the colour wheel, where i is the angle (in degrees) on the wheel. You don't have to constrain i to between 0-360, i will wrap the colour wheel.
pwrLED
pwrLED(True/False) will set the LED to True = on, False = off
