API

USB / UART API to communicate with the IMU Sensor

Sensor Transmit (Tx) API

The sensor transmits data continuously at 100Hz in the format below. Each messages is 19 bytes.

Header	Index	Yaw	Roll	Pitch	X-axis accel.	Y-axis accel.	Z-axis accel.	Reserved	Csum
2 byte	1 byte	2 byte	2 byte	2 byte	2 byte	2 byte	2 byte	3 byte	1 byte
0xAAAA		LSB-MSB	LSB-MSB	LSB-MSB	LSB-MSB	LSB-MSB	LSB-MSB	0x000000

Data	Description
Header	Each message starts with 0xAAAA
Index	8 bit counter (0-255)
Yaw	Rotation around z-axis, range -180 to 180. Clockwise is positive. 0.01 degree increments, e.g. 7435 is 74.35 degrees.
Roll	Rotation around x-axis, range -90 to 90. Counter clockwise positive. 0.01 degree increments, e.g. 1222 is 12.22 degrees.
Pitch	Rotation around y-axis, range -180 to 180. Counter clockwise positive. 0.01 degree increments, e.g. 1356 is 13.56 degrees.
X-axis acceleration	X-axis acceleration in mg
Y-axis acceleration	Y-axis acceleration in mg
Z-axis acceleration	Z-axis acceleration in mg
Reserved	3 bytes set to 0.
Checksum (Csum)	Sum of index, yaw, pitch, roll, and acceleration.

Sensor Receive (Rx) API

To reset the sensor heading direction (Yaw, Pitch, Roll) to 0 send the following command to the sensor.

$MIB,RESET*87

Example Message

Below is an example message sent by the IMU sensor.

Message: 0xAA AA DE 01 00 92 FF 25 08 8D FE EC FF D1 03 00 00 00 E7

Data	Hex	Value
Index	0xDE	222
Yaw	0x00 01	0.01 degrees multiply by -1 for counter clockwise = -0.01 degrees
Roll	0xFF 92	-1.10 degrees
Pitch	0x 08 25	20.85 degrees
X-accel	0x FE 8D	-371 mg or -3.638 m/s2
Y-accel	0x FF EC	-20 mg or -0.196 m/s2
z-accel	0x 03 D1	977 mg or 9.581 m/s2 multiply by -1 for Z-accel. up = -977 mg
Checksum	0xE7