Whats the maximum distance the boe-bots IR pair can communicate at.? (pointing

Clock Loop

Has anyone found this out?

How about in sunlight?

Clock Loop

I guess I must test to see.

Anyone have any suggestions on how to test them to see their max distance? (circuits, and programs)

allanlane5

I would use the "FREQOUT IR_Pin, 1, 38500" to send a 1 mSec pulse.

Then recieve it with another BOE with IR-decoder, and measure the pulse width.

Then move them further and further apart until the pulse width started to drop.

I would assume it would be 10 to 20 feet. It should be possible to up the power on the IR-LED sending the data, or even send to two IR-LED's at the same time, to increase the distance.

Clock Loop

Hmm, i only have a single BS2....

allanlane5

OK, then aim it at a mirror. Use the SSIR sensor to send AND recieve the echo.

FREQOUT IR_Pin, 1, 38500
PULSIN IR_Dec_Pin, ...

An IR-Decoder will 'hold' the signal for a little while after the IR-LED stops sending, which gives you a chance to read the signal with PULSIN. Look up the SSIR sensor on the Parallax website, they have a neat lab.

Note the SSIR is intended for an IR 'whisker'. In that use, it's range can be 'detuned' by the frequency you use with the IR-LED so you get an inch to a few inches in range, off of most surfaces.

I'm sure a mirror will get you better range, however, and will be a more realistic example of two BOE-BOTS trying to talk to each other.

Clock Loop

I measured the distance to be about 4 meters. With the ir transmitter and ir detector pointed at eachother. I added a second transmitter led and there was no increase of distance. The transmitter led alone, had a 330ohm resistor on it with a 38.5khz pulse from the stamp. I would imagine this would make it its brightest without doing damage. Like other leds.

I need to transmit an infared laser like beam at least 20feet.
Anyone have any suggestions?
Infared laser? Are they cheap? Are they safe?
I am trying to detect when the beam is broken.

Tricky Nekro

I used the common Sony led·(for remote controls)·emmiter, and i could mesure distance up to 60cm without pointing eachother... Considering they point each other the distance could exited the 1m!!!

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allanlane5

You might be able to "overdrive" the LED. The 11 mA you've got now [noparse][[/noparse](5 volts - 1.4 volts)/330 == 10.9 mA] would do for continuous use. But you're putting out a modulated signal, then leaving the pin LOW (off) when not in use. You could probably put 25 mA through the LED in those cases -- but you do run the risk of burning out the LED if you inadvertently turn it on continuously.

I'm sure there are "laser diodes" of some description that might help -- but I know nothing about them at this point.

Clock Loop

i'll give the overdrive a try. If im lucky it will let me just reach my distance. If im not it will burn out in too short of a time for this method to be practical.

Thanks.