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Topic: How to Use Laser Distance Meter / laser Rangefinder With Arduino (Read 820 times) previous topic - next topic


Hi All..

I bought laser distance meter with PCB B707C.
They just give me the modul like picture.

please help me..

how to connect it whith arduino ??
where is Tx and Rx ??
what should I solder in the red box (picture)? what is the function?

Thank in advance



Google finds this as the possible manufacturer that you might find details from and the image on that page

implies a UART serial connection (possible 19200 baud).
Don't PM me for help as I will ignore it.


Thanks for the reply
Sorry, I want to ask again. Are other components needed besides the laser module? because I only got the laser module, not with the other components.

I want to use it for Arduino, and there are 4 cables besides power. what are the uses of the cable?
sorry, I am still a beginner in using Arduino, and as soon as I am Arduino only use 2 cables (Tx and Rx) as data communication


Be aware this device interface is probably 3.3V so connecting a 5V Arduino to it may damage it.

As the picture shows the LDM connected directly to a BT module you should be good with UART signals (no need of RS232 adaptor board) as long as they are only 3.3V.

It looks like 2 wires from the battery pack go to power the LDM and then the 4 wires going to the BT module (HC-08) are going to be 3.3V (red), GND (black), RX (blue) & TX (grey)
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Geek Emeritus

look at the picture above. the rectangle at top center is marked HC01

this page shows the many variants of that module: Bluetoooth modules

the one in the picture appears to be this one:

so, left to right, RX, TX, GND, VCC,

so, gray wire RX, blue wire TX
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Find the data sheet for your specific device. That will contain all the information needed on how to connect it (voltage level, power requirements, communication protocol, etc), and the specific commands to communicate with the thing (as that's the obvious next step).

It will also likely tell you what this Bluetooth module is doing. That probably offers another way of communicating with it. Could be more convenient than a wired connection.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.


Sorry for tearing up this old thread but I stumbled into the same pit as the Threadstarter.

I bought this part on Banggood and thanks to this thread I now know that it is manufactured by JRT.

That doesn't help much, though. I emailed them just now and asked if they could provide me the Datasheet and instructions, but I'd be surprised if they answered in a timely manner.

Here's some additional data from the Banggood listing:

  • Interface: 2.8V TTL signal .by PC show date. three wire serial interface ( the single chip microcomputer UART interface), 19.2 kHz.Start bit 1 + 8 + 1 stop bit and no flow contro
  • 2 mA electrical flow: DC2.8V, standby, measuring 120 mA;
  • Laser type: 635nm, 1 mw.(red)
  • Range: 0.02 to 100 meters;
  • Measurement speed: 0.3-3 s
  • Typical accuracy: + / - 2 mm
  • Storage temperature: - 20-60 use temperature: -10-40
  • module  size: Approx  72*40*18mm

Communication and Control:

Communication interface: serial communication (TTL), 19.2K, baud rate parity bit: no parity, data bits: 8;
Function: send capital letters "O" to open the laser, capital letters "C" to close the laser, capital letters "D" for measuring distance, capital letters "S" to view the module temperature and power supply.
Instructions: open the laser, laser, a single measurement, gets to the power supply voltage and temperature.
There's some useful information there, but the main challenge is soldering the right ports.
I mean you can clearly see the + and - connectors, but where do I solder the cable which goes into the digitalPin?

I took a look at that version with the battery pack and I guess it could be the connector with the gray cable?

I'll post any info I (hopefully) receive from the manufacturer.


where do I solder the cable which goes into the digitalPin?
You need two connections to a serial port, to 3.3V RX and from 3.3V TX on a 3.3V Arduino.

In comparison to the radio module connections, it appears that on the laser module, the blue wire should be connected to Arduino TX, and the grey wire to Arduino RX.


Thanks for the info jremington!

The Lady from JRT said she wasn't entirely sure if the product from Banggood was the same as theirs, but she snapped some pictures of the manual with her phone (and sent me the screenshots  :smiley-eek-blue: )

They are low quality and cut off, but I've attached them for you guys.

In the coming days/weeks I'll try to make this work and report back if I succeeded!



 did you manage to solve the reading and connection of your sensor?

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