Maybe make the orientation process more consistent.

main/managementinterface.go

@@ -459,8 +459,9 @@ func handleOrientAHRS(w http.ResponseWriter, r *http.Request) {
 			log.Printf("AHRS Info: sensor orientation: received up direction %d\n", u)
 
 			if f == u || f == -u {
-				log.Println("AHRS Error: sensor orientation: up and forward axes cannot be the same")
-				http.Error(w, "up and forward axes cannot be the same", http.StatusBadRequest)
+				log.Printf("AHRS Error: sensor orientation: up (%d) and forward (%d) axes cannot be the same\n", u, f)
+				http.Error(w, fmt.Sprintf("up (%d) and forward (%d) axes cannot be the same", u, f),
+					http.StatusBadRequest)
 				return
 			}
 

main/sensors.go

@@ -376,6 +376,8 @@ func makeSensorRotationMatrix(g [3]float64) (rotmat *[3][3]float64) {
 
 // This is used in the orientation process where the user specifies the forward and up directions.
 func getMinAccelDirection() (i int, err error) {
+	myIMUReader.Read() // Clear out the averages
+	time.Sleep(500 * time.Millisecond) // Ensure we have enough values
 	_, _, _, _, a1, a2, a3, _, _, _, err, _ := myIMUReader.Read()
 	if err != nil {
 		return

web/plates/gps.html

@@ -61,7 +61,7 @@
 							<span class="col-xs-3 text-center">{{ahrs_heading}}&deg;</span>
 							<span class="col-xs-3 text-center">{{ahrs_pitch}}&deg;</span>
 							<span class="col-xs-3 text-center">{{ahrs_roll}}&deg;</span>
-							<span class="col-xs-3 text-center">{{ahrs_alt}} ft</span>
+							<span class="col-xs-3 text-center">{{ahrs_alt}}'</span>
 						</div>
 						<div class="row">
 							<strong class="col-xs-3 text-center">Mag Hdg</strong>