资 源 简 介
Filament degas project
USB microcontroller implementation for a filament degassing routine
Goals:
controlling a current supply
reading pressure from a vacuum controller
setting a filament current as a function of time and vacuum pressure
send data and receive parameters from a PC (via USB)
Hardware used:
* dsPIC33f
* FTDI FT232R miniboard
Implementation
1. Communication protocol
The hardware layer is RS232, 250kBaud rate.
Communication is based on frames. A Start Of Frame (SOF) byte indicates basic protocol informations.
Pressure to voltage and viceversa conversion
* p=10^(1.667*v-11.33)
* v=(log10(p)+11.33)/1.667
Board photo:
