PNI RM3100 Sensor Suite - Manual (Page 43)

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RM3100 & RM2100 Sensor Suite User Manual Page 42 of 45
5.8.2 Initiate a Single Measurement
The I
2
C transactions to initiate a single measurement on all 3 axes are given below.
START MagI2C ADDRESS RW ACK POLL REG. ADDRESS (N) ACK DATA TO POLL REG (N) ACK STOP
S 0 1 0 0 0 X X 0 0 0 0 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 P
From Host to MagI2C
From MagI2C to Host
After this transaction sequence the MagI2C will initiate a measurement sequence, and
this can run in the background. At the end of the measurement sequence the DRDY pin
is set HIGH and the Status Register will have a “1” in bit 7, indicating data is ready. The
MagI2C will be placed in Idle Mode.
5.8.3 Initiate Continuous Measurement Mode
A sample I
2
C transaction to initiate continuous measurement mode is given below.
START MagI2C ADDRESS RW ACK CMM REG. ADDRESS (N) ACK DATA TO CMM REG (N) ACK STOP
S 0 1 0 0 0 X X 0 0 0 0 0 0 0 0 0 1 0 0 1 1 1 1 0 0 1 0 P
From Host to MagI2C
From MagI2C to Host
In this example, the CMM register is set to initiate measurements on all 3 axes, and to set
DRDY to HIGH after all three measurements are made.
5.8.4 Read the Measurement Results
When the host is ready to read the Measurement Results registers, the following
transactions should occur. Note only the initial Measurement Results register address
needs to be sent, as the MagI2C automatically increments to the subsequent registers.
START MagI2C ADDRESS RW ACK MX2 ADDRESS (N) ACK STOP
S 0 1 0 0 0 X X 0 0 0 0 1 0 0 1 0 0 0 P
From Host to MagI2C
From MagI2C to Host