Data Sheet

Calibration of the CMPS12
The CMPS12 is automatically calibrated by movement, there is no instigation required by the user. The
level to which the CMPS12 has been calibrated can be checked by using command 0x24, bits 0 and 1
of the response byte will start at 0 (xxxxxx00 un-calibrated) and increase to 3 (xxxxxx11) with
calibration.
Storing and erasing calibration profiles
After calibrating the compass the profile can be stored so it will be automatically reloaded when the
module is ready for use again. To do this we need to write a sequence of 3 commands sent in the
correct order.
To store a profile send the sequence 0xF0, 0xF5, 0xF6 to the CMPS12, remembering to pick up the
response byte ok (0x55) after each byte.
If you wish to erase the stored profile so your module powers into a default state send the sequence
0xE0, 0xE5, 0xE2 again each byte will return an ok (0x55).
Changing the baud rate
The default serial baud rate of 9600 can be changed. There are two other baud rates that can be used,
for 19200 just send 0xA0 or alternatively for 38400 send 0xA1. Please note that the CMPS12 will
always default to its 9600 bps rate after power cycling and after setting a new baud rate the ok response
(0x55) will be sent at the newly selected speed.
Board dimensions