dfm17_hamradio

This repo is a development implementation of code to run on a Graw DFM-17 radiosonde

TODO

• Comment existing code
• Decide on functionality of LEDs
• Check crc in ubx payloads
• Decide on gps tick time, currently at once every 5 sec
• Implement GPS lock status based on 1 PPS input (don't update GPS if no tick?)
• Test tone output on 2GFSK
• Implement APRS tick timer (26.4Khz to generate 1200 and 2200)
• Implement RTTY tick timer (100Hz to generate 50Hz, include 75Hz?)
• Implement CRC generation for APRS packets
• Implement morse code OOKing
• Implement APRS with fixed packet data
• Integrate GPS with APRS data
• Implement RTTY data
• Power-up check if running from battery or usb
• Decide on use case for button
• Read ADC samples (battery voltage, usb voltage, current)
• Calibrate ADC

Unknown capability

• Temperature/humidity measurement ("Tmux") operation
• How or if to use NFC based memory

Long term ideas

• Decide if peripherals should be shut off to conserve power
  • when no gps lock, should UART2 and DMA be disabled?
  • when radio is shut down, should SPI be disabled?
  • stop timers when applicable functions are not in use (delay_us timer, baud timers, etc)