TeleBT History

Version 1

The v1 product was based on the same TI RF system on chip part that many of our other early products used. As a result, it required pair programming (meaning you could not update the firmware over USB). That radio was also lower transmit power, and had less receiver sensitivity than the ones used in our current products.

These are photos of the first production version, 1.0:

User View

• 70cm ham-band transceiver compatible with Altus Metrum products, programmed for 38k4 GFSK data rate with forward error correction
• micro USB interface
• 4 pin Tyco MicroMaTch connector for debug and flash programming
• 8 pin Tyco MicroMaTch connector supports serial or SPI interface
• 850mAh LiPo battery charged via USB

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
  • interfaced to Arduino via async serial plus two handshake pins
• Rayson BTM-182 (Bluetooth SPP module) with async interface to CC1111
• 150mA 3.3V LDO regulator
  • input and output appear on 8-pin companion connector
• Firmware 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

Artifacts

For those who don't have ready access to the gEDA suite, here are pdf snapshots of the files for Production PCB version 1.0 in more easily readable form.

• schematic
• pcb artwork
• bill of materials

Version 3

For version 3, we moved to an ARM system on chip and discrete radio chip, which gave the ability to re-flash over USB and better UHF radio performance, but we continued to use the same Bluetooth module.