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IKEA VATTENSTEN low voltage 5V LED strip with Raspberry Pi Pico controller

I recently picked up a few VATTENSTEN low voltage 5V LED strips from IKEA because I figured they’d be easier to integrate into a USB-powered Raspberry Pi or Raspberry Pi Pico project. I was right!

Photo of lights with assembled Pico carrier board

The VATTENSTEN’s power cord is a USB plug on one side, a small PCB capable of only very limited lighting options, and a custom slide-to-fit adapter for the silicone-coated LED strip. I cut the side of the cord with the proprietary adapter and put Dupont connectors on it to make it easier to prototype with.

Ultimately, I decided to build a small carrier board for a Raspberry Pi Pico and contain the circuitry under the socket for the Pico. I had a handy right-angle Dupont socket so I could plug the strip underneath the Pico and have the connector partially supported by the circuit board.

I did take the time to run the GPIO GPIO outputs into a 2222 NPN transistor so the LED strips current wasn’t being pulled through the Pico. Instead, I used the Pico’s VBUS on pin 40 to provide +5VDC to the strip, then connected ground from pin 3 to the emitters of each of the transistors. The Pico’s GP5, GP6 and GP8 were the most conveniently-located pins (7, 9, and 11) to connect to each transistor’s base, and I connected the collectors of each transistor to the LED strip’s red, green, and blue connectors. (Like a few other strips I’ve seen, the order of the colors is irritatingly NOT red, green, blue.)

Photo of completed carrier board without the Pico in place to show the components and wires

To validate it worked, I wrote a very simple CircuitPython script to quickly run through different colors using the Pico’s PWM:

import board
import pwmio
import time

red_led = pwmio.PWMOut(board.GP5, frequency=1000)
blue_led = pwmio.PWMOut(board.GP6, frequency=1000)
green_led = pwmio.PWMOut(board.GP8, frequency=1000)

while True:
    colors = [
        [0xFFFF, 0x0000, 0x0000], # Red
        [0x0000, 0xFFFF, 0x0000], # Blue
        [0x0000, 0x0000, 0xFFFF], # Green
        [0xFFFF, 0xFFFF, 0x0000], # Magenta
        [0x0000, 0xFFFF, 0xFFFF], # Yellow
        [0xFFFF, 0x0000, 0xFFFF], # Cyan
        [0xFFFF, 0xFFFF, 0xFFFF], # White
        [0x1FFF, 0x1FFF, 0x1FFF], # Dim white
    ]
    
    for r, g, b in colors:
        red_led.duty_cycle = r
        blue_led.duty_cycle = g
        green_led.duty_cycle = b
        time.sleep(0.25)

I’m particularly excited about tinkering with the Pico’s hardware PWM because it’s so much higher frequency than my current desk lighting setup that relies on piblaster for software-based PWM. (Little-to-no flicker with high frequencies!)