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LSM303AGR how to get 12-bit resolution on accelerometer

Question asked by Torgeir Jakobsen on Mar 28, 2017
Latest reply on Mar 29, 2017 by Torgeir Jakobsen

LSM303AGR how to enable high resolution mode on the accelerometer? I have done exactly as described in the data sheet/manual setting the LPen bit to 0 and the HR bit to 1. I can play around with these bits but it does not look like I get a change in the resolution. The data written out by my program matches exactly the data bytes shown on my oscilloscope (with serial SPI decoding). The 6 least significant bits are always 0. Setting the BLE bit does not swap the order of the bytes which indicates that I am not able to activate the high resolution mode (BLE only works in high res mode). Anyone who can help here, what is the trick to get 12-bit resolution on the accelerometer?

My register settings:

- CTRL_REG1_A set to 0x67 ( ODR 200 Hz, LPen = 0, all 3 axis enabled)

- CTRL_REG2_A set to 0x00 (high pass stuff disabled)

- CTRL_REG3_A set to 0x02 (FIFO overrun int on int1)

- CTRL_REG4_A set to 0x89 (BDU=1, LSB at lower adr, HR=1 high res, SPI enabled, normal mode)

- CTRL_REG5_A set to 0x40 (FIFO enabled)

- CTRL_REG6_A set to 0x02 (int active low)

- FIFO_CTRL_REG_A set to 0x40 (FIFO mode)


Anyone who have a sequence of register settings which gives 12-bit resolution?