raspberry pi linux waveshare oled fan hat

gistfile1.txt

mount sd cards boot partition
remove console=tty1 from boot/cmdline.txt
add modules_load=pwm_pca9685 to boot/cmdline.txt
add dtoverlay=ssd1306,address=0x3c,width=128,height=32,inverted,sequential to boot/firmware/config.txt
add dtoverlay=i2c-pwm-pca9685a,addr=0x40 to boot/firmware/config.txt

# or

$ echo "dtoverlay=ssd1306,address=0x3c,width=128,height=32,inverted,sequential" | sudo tee -a /boot/firmware/config.txt
$ echo "dtoverlay=i2c-pwm-pca9685a,addr=0x40" | sudo tee -a /boot/firmware/config.txt
$ echo "pwm_pca9685" | sudo tee -a /etc/modules

# or

$ sudo dtoverlay ssd1306 address=0x3c width=128 height=32 inverted sequential
$ sudo dtoverlay i2c-pwm-pca9685a addr=0x40
$ sudo modprobe pwm-pca9685

# configure pwm

$ echo 0 | sudo tee /sys/class/pwm/pwmchip0/export
$ echo 24000000 | sudo tee /sys/class/pwm/pwmchip0/pwm0/period
$ echo 1 | sudo tee /sys/class/pwm/pwmchip0/pwm0/enable

# set fan speed

$ echo 24000000 | sudo tee /sys/class/pwm/pwmchip0/pwm0/duty_cycle

# read temp

$ cat /sys/class/thermal/thermal_zone0/temp

# write to console

$ echo "hello world" | sudo tee -a /dev/tty1