Difference between revisions of "How to control the backlight brightness with PWM(7-B/7-C)"

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(The value of <font color="red">'''X'''</font> should be between 0 and 1024)
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(The value of <font color="red">'''X'''</font> should be between 0 and 1024, 0 brightest, 1024 darkest)
 
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In Raspberry Pi 4B, you need to update the wiringPi GPIO library (Raspberry Pi needs to connect to the Internet):
 
In Raspberry Pi 4B, you need to update the wiringPi GPIO library (Raspberry Pi needs to connect to the Internet):
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(The value of <font color="red">'''X'''</font> should be between 0 and 1024, 0 brightest, 1024 darkest)

Latest revision as of 11:21, 4 August 2020


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This method is only available for 7-B Rev3.2, 7-C Rev3.3 or above

7-C-背光控制-4.jpg



Connect the Raspberry Pi:

7-C-背光控制-21.jpg

In Raspberry Pi 3B/3B+, The backlight brightness can be controlled by following the command:

gpio -g pwm 18 1024
gpio -g mode 18 pwm 
gpio pwmc 1000
gpio -g pwm 18 X

(The value of X should be between 0 and 1024, 0 brightest, 1024 darkest)


In Raspberry Pi 4B, you need to update the wiringPi GPIO library (Raspberry Pi needs to connect to the Internet):

cd /tmp
wget https://project-downloads.drogon.net/wiringpi-latest.deb
sudo dpkg -i -B wiringpi-latest.deb

Execute the following command to control the backlight brightness:

gpio -g pwm 18 1024
gpio -g mode 18 pwm 
gpio pwmc 1000
gpio -g pwm 18 X

(The value of X should be between 0 and 1024, 0 brightest, 1024 darkest)