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Table of Contents
Clock over GPIO
This workaround is not finished jet!
One can use the GPIOs of the Raspberry Pi to generate a clock signal in using Wiring. Wiring for the Raspberry Pi was written by Gordon Henderson.
Install Wiring
In the terminal:
$ sudo apt-get install wiringpi
For the Raspberry Pi 4 one needs to update the WiringPi to version 2.52:
$ cd /tmp $ wget https://project-downloads.drogon.net/wiringpi-latest.deb $ sudo dpkg -i wiringpi-latest.deb
http://wiringpi.com/wiringpi-updated-to-2-52-for-the-raspberry-pi-4b/
Clock the Pin
The clock frequency is derived from the 19.2MHz Raspberry Pi clock. One can use GPIO 4 (pin7), GPIO 5 and GPIO 6.
2.4Mhz would be 2400000
Terminal example:
$ gpio mode 7 clock $ gpio clock 7 2400000
Or in C:
pinMode (pin, GPIO_CLOCK) ; gpioClockSet (pin, frequency) ;