Hi. VE3WGW here Graham..
I am into ham radio I like modifying commercial equipment to operate on the ham bands.
I have a piece of equipment that has 2 PLL's in it. The " original " processors are
set up in a way that it cannot be changed , BUT... I have a Pi Zero that does it quite nicely.
Code for the Pi was written in C a few years ago. The gentleman who wrote the code has passed...
There is no info on the code, but it compiled and works as it should bypassing the internal processors and programming the PLL"s as needed..
As this is for a repeater which is not close it has to run automatically on a power fail and return.
Manually I can type the lines necessary and up it comes.
What I need is help... I am new to the Pi and I can't find a solution ..
The program works in the terminal.
What I have done so far is get the Pi to boot into terminal mode.
I then have to type " sudo su " to get Superuser mode
next cd Rpi to the directory where it is..
Then enter rpi_pll -r 902.4125 -t 927.4125
It does its' thing and all works.
I then enter halt and the Pi goes to sleep.
I cannot enter shutdown as that changes the states of the GPIO and the PLL's go nuts.
What I need the help with is How do I set the Pi up to automatically run the program and then halt?
Any help would be greatly appreciated.