ADC volt Measurer using Infrared

Tex42

Ok i need some help. I have been working on a robot that uses an infrared scaner to avoid walls and other obsticals. However the sensor will not detect anything untill it is about and inch infront of it. I have used the cicuit from the javelin Stamp user's manual on page 55 and have made my own program that prints out the value as the sensor reads it. It is very close to the exmple programe given by the manual. Why is my sensor not working and what can i do to fix it. the sensor is a Sharp gp2d120 3y and it is wired up to the javelin stamp. if there is anyhting else you need to know plz ask i have been stuck on this problem for a long time and need help. So again. Why is my sensor only able to read about one inch infront of it and how can i fix that.
-Thx Tex (Conor)

John Abshier

The sharp sensor you are using is the short range version of the series.· A GP2D12 has twice the range and a GP2Y0A02YK··has 5 times the range. Maximum output voltage is is only 3 volts.· I haven't used a Javelin stamp but have used a Handyboard and an AVR based controller.· For the Handyboard, the ADC ports with the pull up resistor do not work with this sensor.· The AVR based controller has pull up resistors for the line sensors but doesn't use them for the Sharp sensors.