Raspberry Pi Fan Expansion Board SG FAN HAT A

Overview

The Raspberry Pi cooling fan is a dedicated cooling solution designed for the Raspberry Pi. The Raspberry Pi is a powerful little computer, but it can generate some heat when running under heavy load. The cooling fan is designed to provide effective cooling performance and keep the Raspberry Pi running within a reasonable temperature range. It consists of PWM output chip PCA9685, 6 Full-color RGB LEDs WS2812, DC power conversion circuit TPS54331, fan speed indicator LED and other circuits, and can be perfectly connected with the Raspberry Pi 40PIN GPIO header.

Parameters

Usage

Resource Profile

① DC-044 power input jack, the input voltage is DC7-28V

② Fan switch

③ RGB LED WS2812 switch

④ Fan

⑤ RGB LED WS2812 data input pin selection DIP switch

⑥ Raspberry Pi 40PIN GPIO header

⑦ 11-way PWM leading out of PCA9685

⑧ PCA9685 I2C address setting DIP switch

⑨ Fan speed LED

⑩ 6 RGB LEDs WS2812

Wiringpi Library Installation

sudo apt-get install wiringpi
wget https://project-downloads.drogon.net/wiringpi-latest.deb #Version 4B upgrade of Raspberry Pi
sudo dpkg -i wiringpi-latest.deb
gpio -v #

If version 2.52 appears, the installation is successful

For the Bullseye branch system, use the following command:

git clone https://github.com/WiringPi/WiringPi
cd WiringPi
./build
gpio -v

Running "gpio - v" will result in version 2.70. If it does not appear, it indicates an installation error．

If the error prompt "ImportError: No module named 'wiringpi'" appears when running the python version of the demo code, run the following command

For Python 2. x version

pip install wiringpi

For Python 3. x version

pip3 install wiringpi

Note: If the installation fails, you can try the following compilation and installation:

git clone --recursive https://github.com/WiringPi/WiringPi-Python.git

Note: The -- recursive option can automatically pull the submodule, otherwise you need to download it manually.

Enter the WiringPi Python folder you just downloaded, enter the following command, compile and install:

For Python 2. x version

sudo python setup.py install

For Python 3. x version

sudo python3 setup.py install

If the following error occurs:

At this time, enter the command "sudo apt install swig" to install swig. After that, compile and install "sudo python3 setup.py install". If a message similar to the following appears, the installation is successful.

Python Library Installation

#python3

sudo apt-get update
sudo apt-get install python3-pip
sudo apt-get install python3-pil
sudo apt-get install python3-numpy
sudo pip3 install spidev
sudo pip3 install rpi-ws281x

The routine uses the python3 environment, and you need to install smbus to run the python demo code:

sudo apt-get install -y python-smbus

Configure the I2C interface

sudo raspi-config

Enable I2C interface

Interfacing Options -> I2C -> Yes

Install the i2c-tools tool to confirm

sudo apt-get install i2c-tools

View connected I2C devices

i2cdetect -y 1

Check the address and indicate that the connection between the fan board and the Raspberry Pi is successful, the DIP switch is connected to a high level by default (A0~A5 are all OFF), and the displayed address is 0X7F;

Run the demo code

1) Install the SG-FAN-HAT-A on the Raspberry Pi correctly and power on the Raspberry Pi, make sure the fan switch and the RGB LED switch are in the "ON" state.

2) Run the python program:

Enter the python path of demo_codes according to its own path:

cd xxx/fan-hat/python # xxx Represented as its own Raspberry Pi path

Run the program：

sudo python3 fan-hat.py

3) Run the C program:

Enter the c path of demo_codes according to its own path:

cd xxx/fan-hat/c # xxx Represented as its own Raspberry Pi path

Run the program：

sudo make clean
sudo make
sudo ./main

The program prints out the current CPU temperature and fan speed every 1 second. The fan speed is automatically adjusted according to the CPU temperature. The 4 fan speed LEDs on the board and the 6 RGB LEDs at the bottom display different states, temperature values and their corresponding values according to the CPU temperature. The status is shown in Table 1 below:

Table 1

4) Switch function

Turn the switch of the fan and RGB LED from "ON" to "OFF" and check whether the fan and the 6 RGB LEDs have been turned off. If they are not turned off, it is abnormal.

5) Temperature control test

Install sysbench:

sudo apt install sysbench

Start the thread scheduling test:

sysbench --test=threads --num-threads=4 --thread-yields=10000 run

Turn the fan switch to "OFF" and the RGB LED switch to "ON",

Then observe whether the 4 LEDs and RGB LEDs are displayed according to the status in Table 1.

Then turn the fan switch to "ON", at this time the CPU temperature will slowly drop, and then observe whether the 4 LEDs and 6 RGB LEDs are displayed according to the status in Table 1.

6) Boot self-starting test

C：

Open /etc/rc.local：

sudo nano /etc/rc.local

Add the following before "exit 0":

sudo /home/pi/fan-hat/c/main &

Save and restart the Raspberry Pi, and check whether the demo code is running normally after restarting.

Python：

Open /etc/rc.local：

sudo nano /etc/rc.local

Add the following before "exit 0":

sudo python3 /home/pi/fan-hat/python/fan-hat.py &

Save and reboot the Raspberry Pi, and check whether the demo code is running normally after restarting.

Note: c and python code cannot be run at the same time, you should comment out "sudo python3 /home/pi/fan-hat/python/fan-hat.py &" when you need to start up and run C code, and you need to start up to run python code "sudo /home/pi/fan-hat/c/main &" should be commented out.

Resources

Schematic

Product

Data Sheet

PCA9685

Demo codes

Technical Support

Technical Support and Product Notes