TeleDongle

This is an RF interface designed primarily for use as a ground station interacting with a TeleMetrum altimeter on board a high power model rocket. The primary computer interface is USB, but async serial and SPI are also available as alternatives. The RF filter components are by default set for use in the vicinity of 435 Mhz, but can be altered to support other frequency ranges.

Production units are available now from the Garbee and Garbee web store.

Features

User View

• 70cm ham-band transceiver for interaction with 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 2-layer board, fits inexpensive Hammond 1551 plastic enclosure

Developer View

• TI CC1111F32 Low Power RF System-on-Chip
  • Sub-1Ghz transceiver
  • 8051 MCU
  • 32k Flash
  • 4k RAM
  • USB 2.0
  • 6 12-bit analog inputs (11 bits with single-ended sensors)
  • 2 channels of serial I/O
  • digital I/O
• 100mA 3.3V LDO regulator
  • takes input from USB interface by default
  • output appears on 8-pin companion connector
  • can take input from 8-pin companion connector in non-USB applications
• Software Features
  • Written mostly in C with some 8051 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
  • SDCC compiler and source debugger
• Licenses
  • The hardware is licensed under the TAPR Open Hardware License
  • The software is licensed GPL version 2

Production History

Artifacts

The hardware design current gEDA files are available from git.gag.com in the project hw/teledongle.

For those who don't have ready access to the gEDA suite, here are pdf snapshots of files in more easily readable form.

• schematic
• pcb artwork
• bill of materials

This board is an integral part of a TeleMetrum system, and the firmware for both share common elements. More details, including full source code and pre-built packages can be found on the AltOS page on this site.

Future Plans

The current version 0.2 boards "just work", and are available for sale from the Garbee and Garbee web store in either board-only or packaged form.

Several people are working on firmware changes to use these boards as general purpose RF interfaces for Arduino and other microcontroller systems.