HMR3100 Honeywell International's Solid State Electronics Center (SSEC), HMR3100 Datasheet - Page 5

• Manufacturer Part Number: HMR3100
• Description: Digital Compass Solution
• Manufacturer: Honeywell International's Solid State Electronics Center (SSEC)

HMR3100
Calibration Mode
When the host processor pulses low the RTS pin, and sends the RXD pin to a low logic level, the HMR3100 is in
hard-iron calibration mode. This calibration is only for nearby magnetized metals (hard-iron) that are fixed in position
with the HMR3100. At a moderate rate (5 seconds or more per rotation), rotate the HMR3100/host assembly two
complete circles (on a flat, non-magnetic surface if possible) to allow the HMR3100 to take measurements for
compass calibration. At the completion of the rotations, return the RXD to a high logic level. The HMR3100 will return
to sleep mode until another active mode has been initiated. Upon initiation of the calibration mode, the
microcontroller shall output an ASCII STA (53 54 41 hex) indicating a start of calibration and then an ASCII RDY (52
44 59 hex) at the completion of the rotations and the RXD line returned high. Figure 4 shows the calibration mode
timing diagram.
Solid State Electronics Center • www.magneticsensors.com • [phone] • Page 5
Continuous Mode Timing Diagram
Calibration Mode Timing Diagram
Calibration Mode Timing Diagram
Figure 3
Figure 4
Figure 4
SENSOR PRODUCTS