This is an RF interface designed primarily for use as a ground station interacting with Altus Metrum altimeters on board high power model rockets. Think of it as a USB to RF interface. The RF filter components are set for use in the vicinity of 435 Mhz.
MegaDongle is intended to supplement and perhaps eventually replace TeleDongle with a product that provides on the order of 6dB better transmit and receive RF performance, at a modest increase in manufacturing cost.
For the latest MegaDongle firmware and related software, please visit the AltOS page on this site.
These are photos of the current MegaDongle prototypes:
- 70cm ham-band transceiver for interaction with Altus Metrum flight computers like TeleMetrum
- programmed for 38k4 GFSK data rate with forward error correction
- USB interface for power, configuration, and data interface
- 4 pin Tyco MicroMaTch connector for debug and flash programming
- 8 pin Tyco MicroMaTch connector supports serial or SPI interface
- 1.1 x 1.1 inch 4-layer board, fits inexpensive Hammond 1551 plastic enclosure
- Hardware Features
- Software Features
- Written mostly in C with some ARM assembler
- Runs from on-chip flash, uses on-chip RAM
- USB serial emulation for data interface
- Tools Used
- gEDA for schematic capture and PCB layout
The firmware can be found on the AltOS page on this site.
Our version 0.1 design was abandoned after we discovered the need for more processing power to implement in software the same FEC approach provided by the CC1111 we used in TeleDongle.
Three units of version 0.2 prototypes are assembled and seem to work just fine, more work remains to fully characterize their performance and complete their firmware.
No firm schedule for production and sale of MegaDongle has been set yet, but we hope to have this product in production for the 2013 flying season.