BMX055 flat detection

[MiguelSanches]

Dear all,

I am using a bmx055 and I would like to detect when the sensor is at a flat position.

According to the datasheet, the ACC register 0X0C detects if the sensor is at a flat position.

I am using the Arduino IDE and doing the following set of instructions to detect if the sensor is flat.

writeByte(BMX055_ACC_ADDRESS, 0x16, 0x80);  //enable flag to flat detection

byte c = readByte(BMX055_ACC_ADDRESS, 0x0C) & 0x80; // get byte from register, perform AND bitwise to retrieve only the flag bit.

I have been able to detect the flat position but the angle range is a bit higher than the desired. Is it possible to set the range to another value?  The register 0x2E contains the threshold if I am not mistaken, but I can't figure how to translate the range of 0 to 44.8º into the byte that fits the address 

How can I detect if the sensor is at a flat position with an error of +/- 2º for example?

Please advise,

Thanks,

Miguel

[FAE_CA1 · Accepted solution]

Hi,

Thanks for your inquiry. Please refer to the attached How to use "BMA253 flat interrupt in low power mode v1.1.pdf" for more informaiton. It can be applied to the accelerometer inside BMX055.

Thanks.