DeskPi Lite for Raspberry Pi 3B/3B+, With Power Button/ Heatsink with PWM Fan

1. Unscrew the screws on back of the case and paste the thermal pad to Raspberry Pi.

 Please do remember remove the protect film on both side of thermal pad.

  

2. Fix heatsink with fan as following figure:

After that, use 2 x M.2 screw to fix the heatsink to Raspberry Pi.

3. Connect the mainboard with Raspberry Pi as following figure:

4. Put the transparent plastic LED indicator shield into the slot as following figure:

5. Put them all together into the DeskPi Lite case as following figure:

6. Cover the bottom case and fix it with the screws.

And insert the TF card (please flash the image before inserting it into the card slot) into the TF card slot.And then connect the power supply, mouse and keyboard, and connect HDMI cable to your display and select the right signal source on your display, press the power button to turn on.

How to cut off the power?

After safe shutdown your Linux system by typing this command:

sudo init 0

and Long press the power button until the LED color on power button from Blue turn to Red.

How to enable the PWM adjustable fan?

We are assume that you are using Raspberry Pi OS (Official).

1. Press Ctrl+T or click terminal Icon to open a terminal and typing: “sudo raspi-config”

Navigate to 4 Performance Options

and navigate to P4 Fan and select YES.

Keep 14 as default.

select yes, input a temperature in degrees should the fan turn on, Recommend setting to 60 degrees.

select yes and reboot your Raspberry Pi.

If you are using other OS on Raspberry Pi, please refer to how to generate PWM signal in your OS.

Here is a demo code, it will help you to control the fan speed according to the temperature of CPU.

 

Demo code:

#File Name: fan_control.py

#!/usr/bin/python3



import RPi.GPIO as GPIO

import time

import subprocess



GPIO.setmode(GPIO.BCM)

GPIO.setwarnings(False)

GPIO.setup(14, GPIO.OUT)

pwm = GPIO.PWM(14,100)



print("\nPress Ctrl+C to quit \n")

dc = 0

pwm.start(dc)



try:

while True:

temp = subprocess.getoutput("vcgencmd measure_temp|sed 's/[^0-9.]//g'")

if round(float(temp)) >= 45:

dc = 100

pwm.ChangeDutyCycle(dc)

print("CPU Temp:",float(temp)," Fan duty cycle:",dc)

time.sleep(180.0)

if round(float(temp)) >= 40:

dc = 85

pwm.ChangeDutyCycle(dc)

print("CPU Temp:",float(temp)," Fan duty cycle:",dc)

time.sleep(120.0)

else:

dc = 70

pwm.ChangeDutyCycle(dc)

print("CPU Temp:",float(temp)," Fan duty cycle:",dc)

time.sleep(60.00)



except KeyboardInterrupt:

pwm.stop()

GPIO.cleanup()

print("Ctrl + C pressed -- Ending program")



save it and execute it in a terminal:

python3 fan_control.py