I'm certainly interested in a group collaboration.? Much better to have a pool of talent working on this together rather than plugging away at it on my own.
As far as goals are concerned, I'll toss this list out as a starting point for discussion:
General goals:
- uses GitHub for sharing and file distribution
- Initial code supports CW and SSB on multiple bands
- Supports Si5351
- Add various digital modes over time
- Code support for rotary encoders
- Code supports use of both external keypad/switches and external USB keyboard
- Code supports both standard Pi HDMI display output and optional non-HDMI LCD displays
- S-meter support via ADC on HAT
- Display code shows frequency, S-Meter, mode (CW/USB/LSB/etc)
PC board 'HAT' requirements:
- Works with any Pi that uses the standard 40-pin Pi GPIO connector
- Stackable, allowing user to use multiple HATs if desired.? For example, this would allow a user could use add a sound card HAT rather than a USB sound card dongle
- On board 5V/3.3V power supply generation from 12-15V input supply with connector for external power switch (something the Pi's lack)
- Si5351, perhaps on a small daughter-card to allow user to select chip version that best suites them
- Support for external non-HDMI LCD display for those that want a cheaper or smaller display
- Support for external switches/keypads
- Support for 4 or more ADC channels
- On board Relay drivers for BitX 12V/24V power, TX/RX, M1/M2, etc.??
- On board Relay drivers for multi-band BPFs/LPFs.? User can populate PCB for multi-band support or leave off relay driver components for single band support
Optional and/or Future Hardware/Software Features
- Tone generation for tuning/debugging
- Touch screen support
- Real Time Clock (RTC) support
- GPS support (perhaps including grid locator support)
- Digital volume control using either USB Keyboard or additional push-buttons or rotary encoder
- Built in antenna analyzer (perhaps based on W8TEE design, but using Pi for control)
- Support for both Si5351 and DDS
- Built in frequency meter
- Quadrature support for SDR
Notes:
1) Since the various Raspberry Pi models only have 1-2 USB ports (not including the micro-USB input power-only connector), any enclosure should probably include room for an optional small 4 port USB Hub.
2) Although the Raspberry Pi has excellent interrupt support, its interrupt latency can be highly variable.? Any feature requiring precision timing-critial interrupts may have to be handled by a small microcontroller/Arduino.??
3) Depending on proximity/shielding/etc, user may have to disable WiFi and/or Bluetooth on the Pi while using it to drive the BitX/uBitX to limit noise.
Thanks,
Carl, K0MWC
