I ordered a couple of Parallax Ping)))'s for my project, but can anyone recommend a cheap method of measurement of longer distances? Up to maybe 1 or 200m, wouldn’t have to be accurate to more than about a metre.
I also need something with a fairly accurate 2-axis inclinometer and compass. Any ideas? This is to go on a pan/tilt assembly along with the range finder and a directional wifi antenna to do some estimation of the location of wireless access points.
200 meters? x-band radar?
ADXL322 accelerometers, plenty available.
Alan KM6VV
Ahhh I wondered what the accelerometer was that all the gadgets used. Thanks Alan, and I’ll have a look at x-band radar.
For long range, you could try IR sensor like those used to check the range when shooting.
But I don’t know if you can find this kind of sensor alone easily ?
EDIT :
Check this googlelunarxprize.org/lunar/teams/selene/blog/final-rover-design-part-19
They seem to use a conventional Sharps sensor but with a laser diode to get a better range.
That’s an interesting adaption! Have you tried it yet?
Alan KM6VV
Very cool, will investigate
No, just found the webpage yesterday. But it seems to be something interesting as you can find a 808 nm laser diode for under 5$ (you should be able to have a complete sensor for less than 30$).
Also, beware that playing around with lasers (and surely with invisible ones) can be dangerous.
Hi guys,
DIY LIDAR? Sign me up! Anyone have ideas?
My background is mechanical, but I could make use of sensors like this.
You can get a usable LASER diode out of a DVD or CD recorder (google it). But as I understand, you need a driver to control the current to the diode.
Yes BE CAREFUL WITH LASERS!
Alan KM6VV
Hehe I used to work writing software for a company that made plotter-cutter machines with 400W lasers, been through all that laser safety rigmarole 
(yeah it is actually pretty serious I know haha)
I’ll definitely add this to my list of googleables. Hopefully it won’t require much in the way of an external board. My circuit design skills are terrible nigh unto nonexistence.
Thanks! 
A further to my “BE CAREFUL WITH LASERS!” comment,
I got a report today of a tech in our lab looking into a powered optical (IR Laser) shaft encoder!
Always be careful around LASERS, and especially IR, what you can’t see CAN hurt you!
Alan KM6VV
And may be non correctable.
For the driver, it should be something like those used in PowerLed driving, no ? (I’ve made one for two 3W powerled)
As for laser, I’ve worked with 200 kW UV pulsed laser used in industrial engraving production :mrgreen: (We had to use really thick glass panels to sheat the machine and we had to wear special equipment).
If you want to know if a IR led (or laser) is working, try to use a digital camera, they can see IR light (I’ve used this trick to debug my homemade IR obstacle detector).
Yes, I’ve used a digital camera to see my sensor coverage patterns!
Alan KM6VV
