View Full Version : laser ranger-----pity

kelvin james
02-25-2007, 02:11 AM
This was an attempt to hack idea with the $100 TLM100 laser ranger

from Stanley, i think cst-berger own it now. The new circuit

technology has made it too much bother to attempt, but i thought i

would share a look inside.
I do quite a bit of handywork, so it will come in useful anyway. I was

hoping this would be an easy way for people to use some laser ranging

technology for their hobby projects, but it looks like the complexity

would be a major deterent. It works very well, specs are 1/4 in.

resolution at 100 ft., i am getting 1/8 in. up to slightly more than

100 ft. with a good read. In metric it displays to the millimeter.

I took it to work to test it against a linear ( 12 ft), and it is very

accurate. It only took a minute to take it apart, obviously no

attempts to hide anything here. The laser send/receive module is

sealed, so no way to see what the inside looks like. My guess is time

of flight for the reading, specs say it has a 1 nanosecond pulse


As you can see in the pictures, lots of small smt connections, not

easy play with. The lcd is the major trouble, my guess would be around

150 + segment graphic being used. As far as my eyes can tell, the lcd

has 36 leads, and uses that mylar or whatever strip for cable

connection. I suppose the useful info to the lcd could be probed

easily enough, and decoded to interface with a stamp. But the hardware

interface would be a nightmare.

You will notice the 4 circular circuits on the back of the board,

these are the "switches" for the buttons, good idea, but another

problem to remotely activate.

On the up-side, it does have a microwire serial eeprom on board,

probably to store values when doing volume calculations. It may be

possible to read the write data going to the eeprom, something that i

will look into.

It's a letdown that no one has manufactured a cheap ranger module as

a sensor, though i suppose the patents and other crap comes into play

here. Even at work i thought of ideas to use this for such things as

error proofing in assembly areas. Anyway, if anyone has any ideas how

to hack this that is non-destructive , i will give it a try.

I would recommend this tool for anyone thinking of purchasing one for

home/work related use. BTW, I bought this from laserstreet.com, good

service. I already tried a search on the part numbers, and nothing

except the eeprom.

Dennis Ferron
02-26-2007, 02:04 AM
I wonder if the "magic" is happening inside the sealed laser module, and the big microcontroller chip on the buttons-board is just driving the display, or if the laser module is dumb and the large chip on the buttons board is doing all of the calculation?

02-26-2007, 04:23 AM

The large chip has the word 'LEICA' on it, and they doesn't just sell camera lenses, but also some very expensive surveying equipment, so it's a good bet that it is the 'brains' in this setup.

Now, $100 sounds cheap for a laser rangefinder.
Are you certain that this IS a laser rangefinder?

Some only use the laser as a pointer, and does the actual measuring with ultrasonics...
(A picture of the end would help for that)

Don't visit my new website...

02-26-2007, 05:29 AM
Hi All;

The Leica's I have purchased in North America ran about $300 for a true time-of-flight laser ranger.

I made an interface with an SX52 to selected display segments, those were all being clocked at 1 mHz as I recall. Quite a bit of trickery capturing the desired segments .... there were tons (256?) of them, and then mapping those into a table to generate machine readable distances. Ended up working pretty well. As I recall, the actual measuring accuracy was a pretty impressive 1 mm in 30 ft.


Peter (pjv)

kelvin james
02-26-2007, 09:47 AM
Man, i tried to duct-tape this thing, now what do i do?

Yup, she's a real laser range finder, you can shoot this through a keyhole and get a reading, can't do that with sonic, not to mention the 100 ft. range. Leica makes these for Stanley/ Berger whoever, they own the the rights to the technology. The TLM100 is the base model, there is the 200 and 300 also, with higher range and resolution. The time of flight is not magic, if you want some good info, look at the acam website for the TDC chip ( time to digital convertor ). It would not suprise me that they manufacture the chips for Leica. The laser module itself is the mystery to the workings, like a beam splitter for a comparator. I figure trying to do a shift-in from the eeprom data line will give the necessary info, but i have to figure out the configurable bit length, and toss the other address data, etc. The eeprom is made by CSI, a 1 mhz 1K serial, data sheet included below. Having to remotely control the swiches without hardware is a problem. I think the keypad is a conductive material that activates the circuit on the board, pictures included. Attemping to read the lcd data is not going to happen here. For obvious reasons, there is no commercial aspect here other than trying to get an external reading from the unit, to use for hobbiest purposes. Mine came with laser safe glasses, hint---hint.

kelvin james
03-26-2007, 10:11 AM
Still workin on it, just have to bang the 'ol nogin off the wall about another 50 times to make it happen. Nothing like some self abuse, i think it's a hidden fact that programmers like pain. #)

03-28-2007, 07:54 PM
Sure would make a nice altimeter for a Prop based UAV.
Looks to have a few test points on the pcb for calibration or programming?

The Leica chip could be an asic, of the 5 large pads, 1 is ground 2 go into the Leica chip, not sure where the other 2 pins go.
There looks to be an interesting non populated connector in the corner, wonder what it's for?


kelvin james
03-29-2007, 01:10 PM
Thanks for heads-up Gavin, was wondering what the pads were for, shows you how little i know. Maybe they are there for diagnostics, i will definately take a look at it. Yeah, this would be a great sensor for robotics, and numerous other applications. Kinda makes you wonder why the technology has been kept under wraps, i suppose there is some type of " political " issue here, just don't understand it. Anyway, i have lots of patience and don't give up easy, so i will eventually get it to walk and talk, unless someone beats me to it.

03-29-2007, 07:46 PM
Would be interesting to know the update rate too, a few mirrors and servos and you have a 3D scanner.

Did a quick google
Looks like Leica do a few laser range finders.
http://www.lascolaser.com/show_products.php?cat=Hand%20Held%20Distance%20Met er

The Stanley one looks like the cheapest.
Good find find Kelvin, I can remember when the TI Ultrasonic modules first came out, very soon robots everywhere were using them.


05-18-2007, 07:13 AM
Very interesting indeed. It will be great when you can get usable data out of it!
What's the latest?
Any progress?


Tricky Nekro
05-19-2007, 02:53 AM
The big chip as you call it must have a crystal cause probably it's an embedded microcontroller...
And yes it does all the calculations... It also seem to be a LCD driver, not exactly one, but I can't figure out any other ICs...
What I want to point out is that the "head" of the device is probably a stand alone sensor which has it's one IC...
As you can see there is a magnetic GND shield in the back of the sensor... And this is where all the electronics are...
By·seeing the width of the connector (this brown cable - leaf like thing) I can say that it is connected in parallel with the microcontroller...
Probably there are trigger and chip select connections... You won't be able to know until you get the .pdf from the producer of the product or the company which made the sensor if you can fing any readings on the sensor...

Just get to know which sensor is and download the .pdf!!!
Do that and we will be able to help you further...

Friendly advice,
Lefteris Greece...

-Rule your Destiny-
--Be Good. Be Bad. Be Provas--

The hellinic (Greek) robots portal: Greekbotics (http://ptyxiouxos.net/greekbotics/e107/news.php)
Many Projects and Schematics by the users·and also robotic news
(Translate using babelfish (http://babelfish.altavista.com/babelfish/tr))

05-21-2007, 08:36 PM
If there is any electronics in the head then it could be an avalanche photo diode and a preamp.
Shielding would be to protect the sensitive amp from noise?

Just a guess from I design I did a very long time ago, back when red laser diodes were $300 each.


kelvin james
05-22-2007, 12:23 AM
I have been making some progress on this, but being a busy time of year for me, i have not had much time lately to play with it. I am not sure how the whole thing operates, so it is kind of like shooting in the dark. I have searched around the net, and there is no info available. I have been focusing on the data passed to the eprom, but have had some trouble picking up the higher speed stuff. Not sure if that is the right way to go, but it is the easiest to start with. A good scope would help out too. The electronics are very sensitive which is not making things any easier also. I figure the electronics on the back of the laser module is probably the trigger / pulse control for the laser. Anyway, when i get something useful out of it, i will post it here.

05-22-2007, 09:50 PM
kelvin james,
Here is a laser range finder that has a RS232 interface http://www.opti-logic.com/industrial_rangefinders.htm
its a little pricey at 500 dollars but is a real nice unit.

Lord Banshee
06-05-2007, 03:57 AM
Kelvin, i too wanted to do exactly what you are trying to do. I do not have my Stanley yet to work on it though :(

Would you mine taking Higher Quality Pictures of the Front and Back PCB and possible all the chip numbers from each chip.

If you have time to do this thanks,

07-07-2007, 01:27 AM
I poked around on the connector between the main circuit board and the measurment head. Here is what I found starting with connector pin 1 as the one nearest the edge of the board....

1 - 4v power I think
2 - looks low
3 - low, has gnd plain
4 - 3.4v 5.0 mhz afte shot, 10mhz before shot
5 - 10mhz before shote, 5mhz after. ac coupled 200mv or so
6 - 50 uS low-going pulse on trigger
7 - looks like serial clock pulses - 24 pulses multiple times during measurement
8 - gnd i think - connected to pin 3
9 - looks like serial data pulses
10 - seven pulses, 12.5ms long at 50ms intervals
11 - looks like constant 1 volt
12 - 18 pulses 2.3ms long, about 4ms apart. missing pulse after pulse 2
13 - 3.6v whenever power is on
14 - 3.36 v normally, but dips very slightly, apparently as the unit seeks distance
15 - powers up during measurement, powers down with slight decay after more or less 1/2 second
16 - gnd
17 - complicated - initial pulse from 1.7 up to 3.6, then series of 7 up down spikes
18 - even more complicated

pins 7 and 9 look very promising to me. I haven't had time to investigate them further. Maybe one of you can look into it.

07-27-2008, 02:10 AM
Hi all

Been scowering the interenet now for over an hour looking for a really cheap 1 point laser rangefinder that can be interfaced with. It is so ridiculous that this is so hard.

I am a ME working for GDRS. I am used to high quality ladars at work, and just want something cheap at home.


Good luck getting the info from the eeprom, really hope you figure it out and spread the knowledge.

Will post back if i ever find something this cheap but easier.

kelvin james
07-27-2008, 03:35 AM
I hear ya, i have been looking around at this stuff for about 3 years now, and it hasn't improved much. Unless these units are mass marketed, they are going to be expensive. Attempting to make one? Forget it, by the time the laser, photo diodes, beam splitter, optics and electronics are purchased, it would be much cheaper to buy one with a serial output.

Right now, i have my sights set on finishing a sun tracker system. After that, when i finally take the plunge for a good digital scope, i will work on the tlm. I have wanted to do this so the robotics community would have a cheap ranger to use.

By the way, this is one of the few companies that sell oem laser ranger components, i have never bought from them, so i can't give any recommendation.


Post Edited (kelvin james) : 7/27/2008 4:02:23 PM GMT

07-29-2008, 05:02 AM
Thought i would pass this along


I was originally not paying attention to IR sensors.

But sharp claims these will work outside in full sun looking at a black target.

While its not true time of flight, if it works how they say, I might be able to use this.


07-29-2008, 05:27 AM
The sharp rangefinders work by triagulation of the IR beam. The produce an analog output that is related to the range. You can find sample code for use with the BS2 on the Crustcrawler web site. Scan down their downloads page at:

05-02-2009, 05:29 PM

Did you or anyone else ever get anywhere with this laser finder? Sounded like you were making progress and then the thread stops.

Ole Man Earl
05-03-2009, 01:47 AM
This is just what I am looking for to add to my UAV project. Currently I am using a ping sensor, but it is only good out to about 130 ". Works ok for helping on landings tho....
If you need any help, I am retired and do this stuff 12 hrs a day in my lab.

12-23-2010, 02:19 AM
Take a look at: http://porcupineelectronics.com/Laserbotics.html
This interface board provides a USB port for a Fluke 411D which is the same basic laser distance meter as the Stanley TLM100.

08-18-2011, 06:13 PM

Has there been any further progress in hacking into the Stanley TLM-100?