EasyTimer
This board provides two programmable timer-based pyro channels with tilt limits. It is the same size and shape with the same connector layout as our EasyMini flight computer.
The IMU used is the same as on TeleMega and EasyMega, allowing acceleration based launch detection, and gyro-based tilt limiting. This means it's possible to configure a pyro event for some amount of time after launch, or after motor burnout, etc, with the possibility of locking out each event if the rocket is tilted too far away from vertical.
For projects that require staging or air starts, EasyTimer is a low-cost alternative to use of our more expensive products, while retaining the safety aspects of tilt-limiting.
EasyTimer firmware and associated configuration software is part of the AltOS suite.
Photos of the first production unit (the current version 2 looks nearly identical!):
EasyTimer v2 is available for sale now at Bdale's web store and from Altus Metrum distributors.
Features
User View
- Two programmable flight state event and timer-based pyro channels with tilt limits
- USB for configuration
- Designed for use with batteries from 3.7 to 12 volts
- 1.5 x 0.8 inch board
Artifacts
There is a single manual for EasyTimer and most other Altus Metrum products, which is available in html and pdf formats.
This board was designed using lepton-eda and pcb-rnd.
The hardware design files are available from git.gag.com in the project hw/easytimer.
For those who don't have ready access to the gEDA suite, here are pdf snapshots of the files for current production PCB version 2 in more easily readable form:
Previous Versions
All versions of EasyTimer have the same user-visible features and specifications, except that v1 did not contain on-board flash data storage making post-flight analysis .. "challenging". Other than that, the differences are primarily in the choice of processor and sensors, which is driven by availability.
Here are the schematics, artwork, and bill of materials for version 1: