Honeywell HMR3100 manual Introduction, Circuit Description

HMR3100

SENSOR PRODUCTS

INTRODUCTION

The Honeywell HMR3100 is a low cost electronic compassing solution for use in consumer electronics and personal navigation products. Honeywell’s magnetoresistive sensors are utilized to provide enhanced reliability and accuracy in a small, two-axis, solid state compass design. This compass solution is easily integrated into systems using a simple UART interface and binary data format. Performance is optimized for a horizontal circuit board orientations.

SPECIFICATIONS

Characteristics	Conditions
		Min	Typ	Max	Units
Heading
Accuracy	Level		± 5		deg RMS
Resolution			0.5		deg
Repeatability			± 3		deg
Magnetic Field
Range	Maximum Magnetic Flux Density		± 2		gauss
Resolution			6		milli-gauss
Electrical
Input Voltage	Unregulated	2.6	3	5	volts DC
Current	Normal Mode (Average)	0.1	0.2	0.5	mA
	Sleep Mode			1	µA
	Calibration	6.1	7.3	17.3	mA
Digital Interface
USART	USART 9600.N.8.1	2400	9600	19200	Baud
Update	Continuous or Polled	-	2	20	Hz
Connector	8-Pin				-
Physical
Dimensions	Circuit Board Assembly		19 x 19 x		mm
			4.5
Weight			1.5		grams
Environment
Temperature	Operating	0	-	+70	°C
	Storage	-40	-	+110	°C

Circuit Description

The HMR3100 Digital Compass Solution circuit board includes the basic magnetic sensors and electronics to provide a digital indication of heading. The HMR3100 has a Honeywell HMC1022 two-axis magnetic sensor on board. The HMR3100 allows users to derive compassing (heading) measurements when the board is in a reasonably horizontal (flat) position.

The HMR3100 circuit starts with the HMC1022 two-axis magnetic sensors providing X and Y axis magnetic sensing of the earth’s field. These sensors are supplied power by a switching transistor to conserve power with battery operated products. The sensor output voltages are provided to a dual operational amplifier and then to analog to digital

Solid State Electronics Center • www.magneticsensors.com • (800) 323-8295 • Page 2