Radxa-X4 RP2040 Notua PWM-FanControl

PWM-Control for Fans on the Radxa-x4 using the built in rp2040 microcontroller

Equipment needed

• soldering equiment

• copper wire

• dupont-set

• crimping pliers

• wire stripper

• Noctua NF-A4x20-PWM

Create the Cable

The noctua-fan comes with a handy little adapter. Image below.

This adapter has two empty slots for dupont-pins to make this fan work with pwm. For the mod u just need to populate the outer spot of the adapter and crimp it with dupont-male on one side and female on the other. Also extend the red and black wire and also crimp it with dupont female. After u are finished you will have something that looks like this. (image below)

Pinout

Radxa-x4 Pinout in Docs Connect ground (black) to one of the black terminals on the radxa-x4 (Best is pin 6), connect red to one od the two red terminals (best is pin 4) and last connect the pwm-wire in color blue preferably to pin 8.

Finished Hardware-setup

Flash MicroPython onto the RP2040 on the Radxa-x4

Download the project to the radxa-x4 via git or wget or curl.

git clone https://github.com/arag0re/radxa_x4-rp2040-notua-pwm

Download Micropython for the RP2040 using wget from micropython.org.

wget https://micropython.org/resources/firmware/RPI_PICO-20241129-v1.24.1.uf2

U will need sudo apt install gpiod for the script to work on Ubuntu! idk about the other distros. Then create a new bash script using your favorite texteditor called usb.sh with the following content or use the one included in this repository:

#! /bin/bash

sudo gpioset gpiochip0 17=1
sudo gpioset gpiochip0 7=1

sleep 1

sudo gpioset gpiochip0 17=0
sudo gpioset gpiochip0 7=0

Make it executable using chmod:

sudo chmod a+x ./usb.sh

Now execute it to bring the rp2040 into bootloader mode:

./usb.sh

Now you should see a new device listed under /dev/ in my case it was sda. You can check and find it with lsblk. If u found it mount it under a freshly created folder:

mkdir /mnt/pico && sudo mount /dev/sda1 /mnt/pico
ls /mnt/pico
>INDEX.HTM  INFO_UF2.TXT

Copy the uf2 to this device and it should unmount and now run micropython.

cp ~/Downloads/RPI_PICO-20241129-v1.24.1.uf2 /mnt/pico

Its helpful to use vscode-ssh-remote-dev addons to flash the micropython code to the rp2040 using the micropico-addon