TeleGPS v3.0

For the third TeleGPS version, which was manufactured during the Covid-19 pandemic induced global semiconductor shortage, we had to change processor SOCs again. We were able to source enough of a ball grid array version of the CPU we used on v1.0 for this batch. We also moved to the much newer uBlox 10-series GPS modules. Unfortunately, a production process problem reduced yield on this batch.

• NXP LPC11U24FET48 System-on-Chip
• uBlox MAX-M10S GNSS Receiver

Artifacts

Here are pdf snapshots of the design for Production PCB version 3.0:

• schematic
• pcb artwork
• bill of materials

TeleGPS v2.0

For the second TeleGPS version, we moved to a different processor SOC, with a feature that made production turn-on and test easier. We also moved to a more robustly attached USB connector than was used on the original boards.

• ST Micros STM32L151 ARM Cortex M3 based Microcontroller
• TI CC1200 High Performance RF Tran sceiver for Narrowband Systems
• uBlox Max 7Q GPS receiver
• Built-in USB data download and battery charger connection
• 2MB SPI flash

Artifacts

Here are pdf snapshots of the design for Production PCB version 2.0:

• schematic
• pcb artwork
• bill of materials

TeleGPS v1.0

These are photos of production version 1.0:

These early boards used a different processor, a transmit-only radio chip, and had a few other minor differences from current boards.

Features

User View

• GPS tracker and logger
• Offers custom digital telemetry, APRS and direction beacons
• 16mW transmit power
• High-dynamics GPS receiver for accurate tracking
• Uses 3.7V Lithium Polymer battery.
• 1.5 x 1.0 inch board designed to fit inside 29mm airframe coupler tube
• 2MB on-board data logging flash
• Built-in USB connection for configuration, data download and battery charging
• 12.3g flight weight (including antenna, excluding any battery)

Developer View

• Hardware Features
  • NXP LPC11U14 System-on-Chip
    • ARM Cortex-M0 MCU
    • 32k Flash
    • 6k RAM
    • USB 2.0
    • 8 12-bit analog inputs
    • I2C, SPI, async serial
    • digital I/O
  • uBlox Max 7Q GPS receiver
  • TI CC115L 70cm transmitter
  • Built-in USB data download and battery charger connection
  • 2MB SPI flash
• Software Features
  • Written mostly in C with some ARM assembler
  • Runs from on-chip flash, uses on-chip RAM, stores tracking data to flash memory part
• Tools Used
  • gEDA for schematic capture and PCB layout
  • GCC compiler and source debugger
• Licenses
  • The hardware is licensed under the TAPR Open Hardware License
  • The software is licensed GPL version 2

Artifacts

There is a single manual for TeleGPS and all other Altus Metrum products, which is available in html and pdf formats.

The hardware design files can be found on git.gag.com in the project hw/telegps.