Ultrasonic range finder URM37

Please help?

I have recently purchased two of these units from you and am struggling to get them to work on my Arduino.

I connected the sensor as per the manufacturers forum and ran their sketch http://www.yerobot.com/forum/viewtopic.php?f=5&t=7&p=10&sid=72f4c2fbb84bf3 but the code gets stuck here:

do // Loop until pin reads a high value { val = digitalRead(ultraData); }while(val == HIGH);

so it seems the data pin never goes low.

Now the manufacturer states in that forum that boards shipped before 08-2008 needs to be programmed via rs-232 serial to enable PWM output mode. See http://www.yerobot.com/forum/viewtopic.php?f=5&t=5&sid=c50aa4cf567aee4ad61b6305bb4a97b0

I assumed this to be the case with my two sensors? So … I connected one chip to a UartSB also from yourselves and the red led comes on when connected to the sensor. I paid attention to the schematic mentioned in the thread and made sure that the voltage on the uartsb was set to 5v and used the 5V pin and ground to connect to the sensor. The software supplied by the manufacturer does not get a reading from the sensor though and using the ‘enable PWM output’ did not work either?

Will I have to build myself an actual RS232 cable to fix this?

I must also mention for other Arduino users that the serial link on this sensor is true RS232 and cannot be used without some modifications to the sensor (de-soldering and resoldering some small surface mount resistors…) for use with ttl…

You may send following instruction by serial port to enable PWM: 0x44 0x02 0xbb 0x01

This model was RS232 interface, we have TTL version available now, which would listed later. Thanks for the detailed feedback! :slight_smile: