URM37 V3.2 Ultrasonic Sensor Range Finder AVR processor

Introduction
- URM37 V3.2 Ultrasonic Sensor Manual - Rev 2.2URM37 V3.2 Ultrasonic Sensor uses an industrial level AVR processor as the main processing unit. It comes with a temperature correction which is very unique in its class

Specification
- Power: +5V
- Current: <20mA
- Working temperature: -10℃～+70℃
- Detecting range: 4cm-5m
- Resolution: 1cm
- Interface: RS232 (TTL), PWM
- Servo control: One servo control output
- Operating Mode: Serial; (PWM) passive control mode; Autonomous Mode; On/OFF Mode
- Temperature sensor: 12 bits reading from serial port
- Size: 22mm × 51 mm
- Weight: 30g

1. +VCC - +5V Power
2. GND - Ground
3. RST - Reset
4. PWM - PWM Output 0－25000US，Every 50US represent 1cm
5. MOTO - Servo control signal output
6. COMP/TRIG
COMP - On/OFF mode, when the detecting distance is smaller than a pre-set value, this pin pulls low.
TRIG - PWM or RS232 trigger pin
7. NC
8. RXD - RS232,TTL communication
9. TXD - RS232,TTL communication
Compare with other ultrasonic sensor
Compare with SRF08 and XL-MaxSonar-WRC1 Ultrasonic Distance Sensor Evaluating
Hardware requierments

1×URM37 V3.2 Ultrasonic Sensor
1×Arduino Microcontroller
1×IO Expansion Shield For Arduino(V5)
1×USB cable
Tools used

4×jumper wire
Software

User manual:Click Here

Arduino IDE
Working Mode Selection

The working mode can be changed by writing 0x00, 0x01 or 0x02 to EEPROM through serial port.
Mode 1: Serial passive control mode
Under this mode, the sensor is always waiting for command from serial port. Every time it receives a command, it will return the distance and wait for the next command. The degree in the command will be used to control a servo motor to rotate corresponding degree. Please note that this mode is always on. It can not be switch on or off.
Jumper setting for RS232 and TTL output
The selection of RS232 or TTL output level is switched by changing three jumpers (J1, J2, J3). A diagram below illustrates the setting: