Mehmed Blazevic

WallFrame 1/5 - RGB

Introduction

This guide will walk you through the process of setting up Visual Studio Code (VS Code) for programming the Raspberry Pi Pico W using the MicroPico module, and then driving RGB LEDs (e.g. WS2812B). The Raspberry Pi Pico W is a microcontroller board with built-in Wi-Fi capabilities, and the MicroPico module allows you to program it using MicroPython.

RPi Pico W pinout

Prerequisites

All electronics will be explained in a futur post.

Step-by-Step installing environment and testing

Short walks through MicroPython environment from installation to testing the onboard LED.

Step 1: Install the MicroPython Firmware

  1. Download the MicroPython Firmware:
  2. Flash the Firmware:
    • Hold down the BOOTSEL button on the Pico W while plugging it into your computer via USB.
    • This will mount the Pico W as a storage device.
    • Drag and drop the downloaded .uf2 firmware file onto the mounted storage device.
    • The Pico W will automatically reboot with the new firmware.

Step 2: Install VS Code Extensions

  1. Open VS Code:
    • Launch Visual Studio Code on your computer.
  2. Install the Python Extension:
    • Go to the Extensions view by clicking the Extensions icon in the Activity Bar on the side of the window or by pressing Ctrl+Shift+X.
    • Search for “Python” and install the extension provided by Microsoft.
  3. Install the MicroPico Extension:
    • Search for “MicroPico” in the Extensions view.
    • Install the “MicroPico” extension.

RPi Pico W pinout

Step 3: Configure VS Code

  1. Open a Folder:
    • Open a new folder or an existing project folder where you will store your MicroPython scripts.
    • If new project, Ctrl+Shift+P and then “Initialize MicroPico project”
  2. Configure the MicroPico Extension:
    • Go to the Command Palette by pressing Ctrl+Shift+P.
    • Type “MicroPico: Connect” and select it.
    • Follow the prompts to connect to your Pico W board.
  3. Create a New MicroPython Script:
    • Create a new file with a .py extension in your project folder.
    • Write your MicroPython code in this file.

Step 4: Upload and Run Your Code

  1. Upload the Script:
    • Save your script.
    • Use the Command Palette (Ctrl+Shift+P) and type “MicroPico: Upload and Run” to upload and run your script on the Pico W.
    • Or use this icons if connected properly:

Run

Terminal shows up

  1. Interact with the Serial Monitor:
    • To view the output from your Pico W, use the Command Palette (Ctrl+Shift+P) and type “MicroPico: Serial Monitor”.
    • This will open a terminal window where you can see the output from your script running on the Pico W.

Step 5: Example Code

Here is a simple example of a MicroPython script to blink an onboard LED:

import machine
import time

# Initialize the onboard LED
led = machine.Pin("LED", machine.Pin.OUT)

# Blink the LED indefinitely
while True:
    led.on()
    time.sleep(1)
    led.off()
    time.sleep(1)

Step 6: Timer improvements

The folowing code provides another way of driving the led by setting a timer (newbies)


import machine
import time

# Initialize the onboard LED
led = machine.Pin("LED", machine.Pin.OUT)

# Create a Timer object
timer = machine.Timer()

# Define a function with timer as parameter
def toggle_led(timer):
    led.toggle()

# Initialise the timer to call the function *toggle_led* 
# *period* in milliseconds
# *mode* calling the function periodically (vs one shot)
# *callback* the function to be called
timer.init(period=200, mode=machine.Timer.PERIODIC, callback=toggle_led)

def main():
    print("Hello, world!")
    while True:
        ... # do what you want


# Call main function
main()

You can find it here

LED

RGB

Here is an example on how to drive the RGB stripes.

Initialisation

# Setting the GP0 pin (#1 on the RP2040's connector)
pin = machine.Pin(0)
# Setting the number of stripes
ledQty = 2
# Create a strip object
strip = neopixel.NeoPixel(pin,ledQty)

Set colors & write to strip

# set color BRG (24=3*8 bits)
b = 30
r = 30
g = 0
strip[0] = (b, r, g) # type: ignore | purple
b = 0
r = 30
g = 30
strip[1] = (b, r, g) # type: ignore | yellow
strip.write()s

RGB first colours

Do something random

# Do something completly random (what? it's my code!)
while True:
    time.sleep_ms(20)
    b = b+10
    g = g+5
    if b > 80:
        g = g+10
    strip[0] = (g,30,15) # type: ignore
    strip[1] = (0, b, g) # type: ignore
    strip.write()

RGB random

Next

At this stage, all components have not been selected. Details regarding the electronics will be outlined in a separate post. The next one will focus on how to run an HTTP server on the Pico, and drive the LED via the server. For more information, please see: https://github.com/mekiisupertramp/wallframe/blob/main/rgb.py