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URM V3.2 Ultrasonic sensor

URM3.2_Mannual_Rev2.pdf306.71 KB
Vendor's Description: 

URM37 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.

Direct control through RS232, easy to control by PC.



Power: +5V
Current: <20mA
Working temperature: -10 ~ +70 C
Detecting range: 4cm-5m
Resolution: 1cm
Interface: PWM, RS232 or TTL (via Jumper)
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 



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I decided for this ultrasonicsensor but i have a problem: I will change the mode (write on the EEPROM) and I want to use the mode 3(default mode1)

So I connected the sensor with my pc RS232 interface (programm docklight)

(my pc RS232 interface is an adapter for usb to RS232)
I tried to measure the command of docklight and I think it´s ok!

Baudrate: 9600 / Stopbit: 1 / Paritybit: None / Data bits: 8 / command: 0x44 0x02 0xbb 0x01 (mode 3) / Jumper setting: RS232
Connection: (RS232 <-> sensor: RXD <->TXD, TXD <-> RXD), sensor:GND, 5V

So i send the command to the sensor but i don´t get any information back to docklight and the mode also don´t change.

Has I forget something? Or do I something wrong?

Tanks for your help!

Can this thing work with Picaxe? If so this might be a good competitor for the SRF005 ! 

Yes. It does allow users to send serial command to control a servo. And Mr Miles has developed an Arduino library for this little sensor, and it should be very easy to use. 

Here is the download link: http://download.milesburton.com/Arduino ... 37_2.0.zip

Interesting device and a great price. I took a quick look at the manual. Does the servo control function allow this sensor to commnand a servo? It looks like a very impressive sensor.

Has anyone used one with a PICAXE?

Arduino supports Parallax's Ping, but not this one. If I buy it, were do I find information about the code needed to use it?

How do you access the serial control of the URM V3.2 via an Arduino - has this been documented anywhere.

I know you have to change to "Mode 1: Serial passive control mode" do you have any schematics of how to do this ?

Does this mean i have to desolder the SMD R16,17,15 and resolder to R18,19 for it to work off the Arduino Serial Port ?

Do you supply them with this modification already done ?


This would be a much better way to control it - plus its got a temparature probe installed.....

 Using this mode releases the Processor and lets the module do all the work. (ie just a simple serial read)


You are right. You have to desolder the SMD R16,17,15 and resolder to R18,19. Hope this answer your first question. 

Thanks for quick reply ,thats perfect - gives me a bit more confidence to desolder the the SMDs now.

Did you notice Mr.Flex has one of your URMs installed.....

SMD resistors easy to change - phew.....

Please could you help me with the mode change - if we get this working then i am sure the LMR crew will pick up thier ears.

Reading the Manual its not clear what value i should be sending to the module to change  to:-

Mode 1 - serial passive control mode.


I assume i must send this to the module:-

0x44 + 0x02 + (0x??) +0x22  -  can you help me with the  ?? ....... it only shows mode 2 (0xaa) and mode 3 (0xbb).

Thanks in anticipation.