- Sun Mar 22, 2009 10:24 am
#68979
I am having difficulties getting proper readings from the honeywell HMC5843 3-axis compass.
The device is connected in single supply reference design (3.3v) as shown in the datasheet. And an STM32 microcontroller for I2C Comms all on a single pcb. I have tried two chips from digi-key and they both have the same results.
I am able to properly connect and read / write registers over the I2C bus at 100khz (i.e. the Config Registers A,B and Mode as well as ID Registers 'H43' set & read fine).
The problem is the X,Y,and Z axis readings are bogus. When in continuous sample mode with sensitivity at default +-1 Gauss, the readings I get in ADC counts are: x-axis about +-4, y-axis +-5, z-axis +20
When in self test operation as described in the datasheet readings are X:~40, Y:~40, Z:~60, though they should be close to 715 ADC counts. Different sensitivity settings don't achieve different results.
Has anybody had any success with the HMC5843?
The device is connected in single supply reference design (3.3v) as shown in the datasheet. And an STM32 microcontroller for I2C Comms all on a single pcb. I have tried two chips from digi-key and they both have the same results.
I am able to properly connect and read / write registers over the I2C bus at 100khz (i.e. the Config Registers A,B and Mode as well as ID Registers 'H43' set & read fine).
The problem is the X,Y,and Z axis readings are bogus. When in continuous sample mode with sensitivity at default +-1 Gauss, the readings I get in ADC counts are: x-axis about +-4, y-axis +-5, z-axis +20
When in self test operation as described in the datasheet readings are X:~40, Y:~40, Z:~60, though they should be close to 715 ADC counts. Different sensitivity settings don't achieve different results.
Has anybody had any success with the HMC5843?