This is a small, baro-only recording dual-deploy altimeter for model rocketry

For the latest EasyMini firmware and related ground station software, please visit the AltOS page on this site.

Features

User View

• Recording altimeter for model rocketry
• Supports dual deployment (can fire 2 ejection charges)
• Barometric pressure sensor good to 100k feet MSL
• Designed to use a battery supplying 3.7V-12V.
• 1.5 x 0.8 inch board designed to fit inside 24mm airframe coupler tube
• 1MB on-board data logging flash
• Weighs only 6.5g (less than 1/4 oz)

Developer View

• Hardware Features
  • STM32F042 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
  • Measurement Specialties MS5607 pressure sensor
  • 1MB SPI flash
• Software Features
  • Written mostly in C with some ARM assembler
  • Runs from on-chip flash, uses on-chip RAM, stores flight 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 shorter manual for EasyMini which is available in html and pdf formats.

Thanks to Bryan Duke, there's also a 3d model of EasyMini available on Thingiverse.

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

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