HMR3100 Honeywell International's Solid State Electronics Center (SSEC), HMR3100 Datasheet - Page 3

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

HMR3100
Note the “North Arrow” printed on the HMR3100 circuit board top side. This is the mechanical reference for product
alignment purposes. When placed on the development kit’s RS-232 motherboard assembly, this arrow also points
toward the 9-volt batterypin block on the motherboard (away from the RJ-11 jack).
Pin Configuration
The HMR3100 board is 0.77” on each side with eight pins in groups of four spaced at 0.6” apart in wide-DIP format.
Seated height is approximately 0.275”. See Figure 1 for further mechanical details.
USART Communication Protocol
HMR3100 module communicates through binary data and ASCII characters at four selectable baud rates of 2400,
4800, 9600, or 19200. The default data bit format is USART 9600.N.8.1. The baud rate selection is determined by
the position of jumpers J1 and J3. These jumpers are zero ohm SMT resistors (jumpers) and are normally high (logic
1) when removed, and grounded (logic 0) when in place. At 2400 baud, no jumpers are present for a 1,1 logic
presentation. At 4800 baud J3 is present for a 1,0 logic presentation. The factory default setting of 9600 baud is
created by a jumper present on J1 for a 0,1 logic presentation. With J1 and J3 jumpers present for a 0,0 logic
presentation, the compass module works at 19200 baud. See Figure 1 for jumper locations. Jumper J2 is for factory
testing, and J4 is for Y-axis inversion should the end-item mount of the HMR3100 module be upside down (pins up).
Solid State Electronics Center • www.magneticsensors.com • [phone] • Page 3
Pin Number
1
2
3
4
5
6
7
8
RTS
RXD
Pin Name
VCC
NC
NC
TXD
GND
NC
0.77”
Pin 1
Pin 4
J1 J2 J3 J4
HMR3100 Pinout
Top Side
Figure 1
2 C
Power Supply Input
No Connection
No Connection
Receive Data Input
No Connection
Description
Ready To Send Input
Transmit Data Output
Power and Signal Ground
xtal
0.77”
Pin 8
Pin 5
SENSOR PRODUCTS