This project response to my need of an universal high voltage power supply to be used with mostly all type of geiger tubes that I have in my collection.
I’ve needed a selectable output voltage between 300V and 900-1000V, low power output, on board pulse counter and maybe a display. All powered by 5V
There is also a JTAG connector for uploading new firmware via a USBAsp programmer. During operation the jtag pins 3 and 4 becomes RX/TX uart. Pin 1 is GND.
The voltage selection jumpers are made to select output voltage when the board is used stand-alone. Make a solder bridge according with the table below and you’ll get the corresponding output voltage out.
The firmware is in currently developement but it’s already stable, counts pulses, display voltage and also send info like pulses/voltage via UART.