High-precision magnetometer calibration is suitable for products that have already been packaged,
and other methods are used for bare boards.
1.Fix the electronic compass in the use environment, and try not to carry magnetic items such as keys
and mobile phones during calibration;
2.Connect the product to the system and put it in a horizontal state(within ±5°);
3.Open the serial debugging assistant and send the start calibration command in hexadecimal format:
77 04 00 08 0C.The rotation process should be as slow as possible and rotate at a uniform speed. The
time of one rotation is about 10~15 seconds;
4.Starting from 0 degrees defined by yourself, the acquisition command is sent every 30 degrees,
waiting to receive the return command and then continuing to rotate until the product rotates
around the Z axis for a total of 13 points.
[Acquisition command: 77 04 00 A1 A5, return command: 77 05 00 A1 XX YY, XX is the hexadecimal
number corresponding to the collection point, and the return value corresponding to the last point is
0D.]
5.Send end calibration command: 77 04 00 A2 A6, received return value: 77 05 00 A2 00 A7.
6.Wait for about 20~30s until the sensor returns to the end command: 77 05 00 A2 01 A8, the
calibration is completed.
无锡北微传感科技有限公司
www.bwsensing.com Tel: +86 510 8573 7158
BMR3300
Three-Axis Accelerometer Three-Axis Magnetometer
High Accuracy Electronic Compass
Method 2 - Multi-face calibration:
1.Fix the electronic compass in the use environment, and try not to carry magnetic items such as keys
and mobile phones during calibration;
2.Connect the product to the system and put it in a horizontal state(within ±5°);
3.Open the serial debugging assistant and send the start calibration command in hexadecimal format:
77 04 00 08 0C, return value 77 05 00 88 00 8D;
4.The product is placed horizontally, face up (pitch and roll are within ±5°), rotate one revolution at a
constant speed approximately and use for more than 10 seconds.
5.The product is placed horizontally, with the mounting surface facing up (pitch and roll are within ±5°),
rotate one revolution at a constant speed approximately and use for more than 10 seconds.
6.The product is placed in a vertical state, the smooth side of the casing is facing downward (the pitch
and the roll are both within ±5°), rotate one revolution at a constant speed approximately and use for
more than 10 seconds.
7.The product is placed in a vertical state, and the other smooth side of the casing faces downward
(the pitch and the roll are both within ±5°), rotate one revolution at a constant speed approximately
and use for more than 10 seconds.
[Where step 4.5.6.7 can be exchanged];
8.After the four faces have been rotated, send the hexadecimal command 77 04 00 09 0D to save the
calibration and return to 77 05 00 89 XX YY. (XX represents the calibration error coefficient, the
smaller the value, the better, less than 1 is ideal, FF indicates calibration failure, and YY is the
checksum of the command);
9.Calibration completed
Method 3 - High-accuracy magnetometer calibration＞
Note: Do not power off or send other commands before receiving the end command to prevent the
sensor from losing data.
Bewis Sensing Technology LLC www.bwsensing.com Tel：+86 189 0617 7922
