IR Range Finder Ruler

[Alfa_Zulu]

Hey, this is my first post here and I hope someone can help.

I'm wanting to make a device that uses an IR Range finder to display a distance (in metres) on an LCD screen
I have some experience with making basic-moderate circuits using IC's not a problem, although I have had trouble
programming EEPROM's in the past so I'd like to avoid micro controllers if possible.

Thanks in advance.

[Soeren]

Hi,

This is easy with a microcontroller, but will be quite a bit of work (and a large(ish) PCB) to get even slightly precise.
The output function of an IR range finder is not linear and with a controller, you can make a table translation or find the function f(x)=?Y and use that - all with some lines of code, while with a discrete build...
And driving an LCD will be so much easier with a controller as well.

[Alfa_Zulu]

hi,

yeah i thought that the microcontroller would be the way to go, so pretty much just input the voltage and use a function to find the distance value?. any help with a basic schematic would be greatly appreciated and i have an atmega8 laying around, would that be sufficient for this do you reckon?

Thanks

[Conscripted]

The atmega8 should be able to handle this project. Do you have a board to put your controller in? If not there is a build on this site that will get you a workable solution. Look for the $50 robot and disregard the parts you don't need.  Good luck with your project and let us know how it goes.

Conscripted

[Alfa_Zulu]

ok thanks, it there a tutorial or something here on how to drive a lcd with a microcontroller? i've had a look but couldnt find anything, once i know how to do that i think the rest should be pretty straight forward i think lol.

[cyberfish]

Yes, the datasheet .

[paulstreats]

You need to be more specific about the LCD.

Is it text/graphic?
How does it receive data? through a parallel data bus with EN pin, or serial rx/tx or SPI I2C etc...

[Alfa_Zulu]

You need to be more specific about the LCD.

Is it text/graphic?
How does it receive data? through a parallel data bus with EN pin, or serial rx/tx or SPI I2C etc...

ok sorry, this is what i dont know, i've never used one before, what would you suggest to be the easiest to work with?

[cyberfish]

I suggest something like this -
http://www.sparkfun.com/commerce/product_info.php?products_id=255

It's fairly simple to work with, and well documented.

Only downside is it's parallel, so it will need a bunch of pins from the microcontroller (11).

I've worked with it quite a bit before, and it's a very common LCD controller, so I'm guessing many other people have as well.

We can help if you get stuck.

If you choose one that no one has used, you'll probably be on your own.

[Alfa_Zulu]

ok sweet thanks, i'll have a look at the documentation and if i can't figure out how to send text to it i'll be back lol

btw, with the ir range finders does anyone know what type of max range you can get with them, with the sharp ir rangers i was looking at they said about 6cm-30cm which isn't a very long distance.... thanks

[cyberfish]

There are a few versions with different ranges.

The GP2D12 for example can do 10 to 80cm.

[Alfa_Zulu]

so I take it that you cant get much more distance than about 1 metre? I was kind of hoping for at least 10 metres.
is there an equivalent sensor that can do around that distance or more?

[Joker94]

10 m is a push, i dont know of any sensors for that.

a ping ultrasonic sensor can get about 3m.

http://www.parallax.com/dl/docs/prod/acc/PingDocs.pdf

may be a laser sensor may be suitable for what you need

Cheers

Joker94

[Alfa_Zulu]

ok thanks, so i think that a laser ranger might be the way to go as I want it for short
to medium distances rather than precise small distances. anyone know of a decent
laser ranger module that i could use for this?

Thanks!

[Soeren]

Hi,

[...] anyone know of a decent laser ranger module that i could use for this?

Yes, the Bosch DLE40 Professional, measures 5 cm to 40 m in less than 0.5 s with an accuracy of +/- 1.5 mm.
And best of all, it comes; totally assembled with an LCD display and options for measuring 2 or 3 dimensions (for area and volume), a belt pouch and in a box at least 20 times its size.

It's so well built that I haven't yet had the hearth to hack it 

[Alfa_Zulu]

lol the point was to make it to learn. 

anyway thanks for everyone's help/advice but I'll shelve this until I can afford to do something lol