X-Git-Url: https://git.gag.com/?p=fw%2Faltos;a=blobdiff_plain;f=doc%2Fmotortest-installation.inc;fp=doc%2Fmotortest-installation.inc;h=8a4cd77fb0eb7ce29f468a7d442190cb9c6d5977;hp=0000000000000000000000000000000000000000;hb=afc90f63c6a0c2a511fddc97b72537e0a6f40cfd;hpb=7f4059bbe74ecf86842134739ec521dcb646f04f

diff --git a/doc/motortest-installation.inc b/doc/motortest-installation.inc
new file mode 100644
index 00000000..8a4cd77f
--- /dev/null
+++ b/doc/motortest-installation.inc
@@ -0,0 +1,51 @@
+== 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.
+
+	=== Power Switch and Battery
+
+		In addition to the circuit board itself, EasyMotor needs 
+		a power switch and battery to operate.  Unlike most other 
+		Altus Metrum products, EasyMotor does not work with 
+		single-cell LiPo batteries.  That's because commonly
+		available inexpensive pressure sensors need 5V, which is
+		more than a single-cell LiPo provides.  Any battery that
+		provides from 6.5 to about 15 volts should work.  Good 
+		choices are the common 9V alkaline battery, or the very 
+		small and light A23 12V alkaline batteries.
+
+		Because he often mounts EasyMotor to the motor's forward 
+		bulkhead instead of to the airframe itself, Bdale often 
+		uses a length of "shooter wire" from an e-match or used 
+		motor igniter as a power switch, routing the wire out of 
+		the typical fin can vent hole and using "twist and tape" 
+		to power up the board.  Whatever works!
+
+	=== Pressure Sensor
+
+		The primary motivation for designing EasyMotor was to have
+		a reliable way of recording motor chamber pressure during
+		flight.  To that end, EasyMotor supports attachment of a
+		low-cost analog pressure sensor.  The board provides 5V
+		to power the sensor, and an input for measuring and 
+		logging the output voltage from the sensor.
+
+		The kind of sensor EasyMotor is designed to work with
+		takes 5V in and has a linear analog output that ranges
+		from 0.5V at 0 to 4.5V at the maximum pressure supported
+		by the sensor.  Very inexpensive sensors that have a 
+		"1/8 NPT" threaded input, a "Buick-style" 3-pin connector,
+		and typically ship with a short cable and mating 
+		connector, are readily available on eBay and AliExpress.
+
+		To log in-flight chamber pressure, a typical approach
+		might be to drill a 1/8" sampling hole all the way 
+		through the center of the motor's forward closure, then
+		drill and tap partially through the closure with a "1/8
+		NPT" pipe tap.  Fill the touch hole with grease, screw in 
+		the pressure sensor, and attach the sensor leads to 
+		EasyMotor.