From 96181ff1e0d376d7a2c9519abbf4f346d8fd47ea Mon Sep 17 00:00:00 2001 From: Bdale Garbee Date: Thu, 19 Jan 2023 22:41:24 -0700 Subject: [PATCH] doc: update EasyMotor behavior description for firmware 1.9.13 and later --- doc/motortest-installation.inc | 27 ++++++++++++++++++++++----- 1 file changed, 22 insertions(+), 5 deletions(-) diff --git a/doc/motortest-installation.inc b/doc/motortest-installation.inc index 1edee68d..3914bc70 100644 --- a/doc/motortest-installation.inc +++ b/doc/motortest-installation.inc @@ -1,10 +1,27 @@ == Installation - EasyMotor needs to be rigidly attached in the airframe, and the - long axis of the circuit board needs to be aligned with the axis - of flight. By default, the round beeper on the board should be - “up” towards the nose cone, and the screw terminal strips should - be “down” towards the fins and motor nozzle end of the rocket. + [WARNING] + Firmware versions prior to 1.9.13 used acceleration to detect + launch. Starting with 1.9.13, the firmware switched to using + pressure to trigger recording. Altus Metrum strongly recommends + upgrading all EasyMotor boards to current firmware, the + behavior of which is described here. + + EasyMotor needs to be rigidly attached in the airframe, in any + convenient orientation. + + === Trigger to Start Recording + + Starting with firmware version 1.9.13, a pressure sensor must + be attached, and pressure change is used to initiate and conclude + data recording. Pressure and 3 axes of acceleration are recorded + for later analysis. + + EasyMotor looks for a 50 psi rise in pressure from ambient to + start recording. Recording stops when the pressure drops + below 50 psi and shows variation of less than 30 psi for at + least 10 seconds. These conditions are intended to capture all + actual burn data including anomalies such as "chuffs". === Power Switch and Battery -- 2.30.2