From 20891312557a0c10d9a2c469d1722a0e09d25780 Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Thu, 1 Jan 2009 10:44:28 -0700 Subject: [PATCH] documenting original project --- AltusMetrum/index.mdwn | 52 +++++++++++++++++++++++++++++++++--------- 1 file changed, 41 insertions(+), 11 deletions(-) diff --git a/AltusMetrum/index.mdwn b/AltusMetrum/index.mdwn index 890f29b..8ce1f91 100644 --- a/AltusMetrum/index.mdwn +++ b/AltusMetrum/index.mdwn @@ -1,19 +1,49 @@ # AltusMetrum

-Welcome LCA, SCALE, and OLS 2008 attendees! -Thanks for looking, but there's not much here yet... +This is the design that started it all! Bdale got frustrated with existing +commercial altimeters and decided to build his own. This project was +presented in talks at LCA, SCALE, OLS, and Debconf in 2008.

- -

-Information on the OpenAlt model rocketry avionics system coming very soon! -

-

-Here are photos of the version 0.1 PCB, which has enough issues to not be -worth duplicating. Version 0.2 is coming soon, and will be fully documented -on this site! +Here are photos of the front and back sides of the version 0.1 prototype PCB.

- +## Features ## + +### User View ### + +* Recording altimeter for model rocketry +* Supports dual deployment (can fire 2 ejection charges) +* Primary operations based on pressure sensor +* 3-axis accelerometer +* Temperature sensor +* 2 serial ports for attachment of GPS and RF link modules +* USB for data recovery and post-flight power source +* Flexible battery choices +* Designed to fit 24mm airframe tube + +## Problems ## + +In addition to the various "oopses" that were found and fixed during initial +turn-on of this board, several issues contributed to the decision to shelve +the design for now: + +* lots of work went in to trying to make the board fit in a 24mm airframe, + but the resulting design with battery is really too heavy for such a small + rocket. + +* the 3-axis accelerometer has a max scale of +/- 6g. This is insufficient + for characterizing the kinds of motors that we're playing with now. + +* while using a gcc-based toolchain to cross-develop for the ARM7 core works + reasonably well, it's a heavy toolchain to build and maintain, and the + processor really is serious overkill for the task at hand. + +## Artifacts ## + +The version 0.1 design had enough issues that Bdale decided not to publish +it. Work on an 0.2 revision is mostly complete at the schematic level, and +some printed circuit board artwork updates were made, but a second run of +boards was never attempted. This design is now mostly of historical interest. -- 2.47.2