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Sensor will not respond, help? — Parallax Forums

Sensor will not respond, help?

MacadaciouseMacadaciouse Posts: 16
edited 2010-10-11 14:21 in BASIC Stamp
I'm using the sharp GP2Y0D340K IR range sensor for an obstacle-avoiding robot.
(datasheet: http://sharp-world.com/products/device/lineup/data/pdf/datasheet/gp2y0d340k_e.pdf)

I had it working a few months ago (briefly) but then of course I was called away to other projects and forgot how I had it set up. I can't even figure out how to connect it to the breadboard without it overheating. The most logical setup seems to be
1-Vdd
3-in 15
4-Vss
This setup is used here with apparent success: http://courses.cit.cornell.edu/ee476/FinalProjects/s2007/bt48_rsr32/bt48_rsr32/sensorcrt.jpg

No matter what I do though, my board will not respond to the sensor. If everything is plugged in, I get an endless stream of 1's. If something is unplugged/loose, I get an endless stream of 0's or occasionally 1010101010 etc.

The test program I am using is as follows:
' {$STAMP BS2}
' {$PBASIC 2.5}
INPUT 15
test_routine:
DEBUG "sensor = ", BIN1 IN15, CR
GOTO test_routine

Is something not hooked up correctly? Is the programming wrong? I've had about as much as I can stand from this project, this just shouldn't be that difficult. Please, if anyone has any advice I'll give it a shot, I'm about to just pitch the sensor all together.




My end goal is a robot that will turn when it encounters a wall, the program I wrote a few months ago is as follows:
' {$STAMP BS2}
' {$PBASIC 2.5}
main:
IF IN15 = 1 THEN
GOSUB go
ELSE
GOSUB turn
ENDIF

go:
HIGH 14
HIGH 13
DEBUG "go"
GOTO main

turn:
LOW 14
LOW 13
HIGH 12
HIGH 11
DEBUG "turn"
PAUSE 500
LOW 11
PAUSE 500
LOW 12
HIGH 14
HIGH 13
GOTO main

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2010-10-11 14:21
    You do need a filter capacitor between pin 5 and ground. The datasheet says 0.1uF while the Cornell link says 1uF. Probably anything in that range will work.

    According to the datasheet, you should get a "1" output whenever there's something in front of the sensor at any distance up to about 0.4m.
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