Diff: main.cpp

Revision:

5:3c4f35ea3cd9

Parent:

4:66928695da01

Child:

6:9d9e7c9adc7c

--- a/main.cpp	Tue Feb 19 20:38:58 2013 +0000
+++ b/main.cpp	Tue Feb 19 21:37:32 2013 +0000
@@ -11,6 +11,13 @@
 #define LOGGING_INTERVAL    0.1
 #define ANALOG_SCALE        3.3
 
+//potential divider scaling factor = 2/3
+#define ACCEL_SCALE         20.0 / (10.0 + 10.0)
+#define ACCEL_BIAS          0.5
+//312mV per g at 5V full scale
+#define ACCEL_SENSITIVITY   312 * ACCEL_SCALE
+
+
 State car;
 CANComms* can;
 
@@ -61,8 +68,9 @@
     telemetry.warnings = car.warnings;
     telemetry.voltage = car.voltage;
     
-    telemetry.accel_x = analogInputs[4].read();
-    telemetry.accel_y = analogInputs[5].read();
+    //convert the accelerometer values to g
+    telemetry.accel_x = (analogInputs[4].read() - ACCEL_BIAS) / ACCEL_SENSITIVITY;
+    telemetry.accel_y = (analogInputs[5].read() - ACCEL_BIAS) / ACCEL_SENSITIVITY;;
     
     pb_encode(&pb_out, telemetry_message_fields, &telemetry);
     pb_write(&pb_out, &zero, 1);