Infrared Proximity Sensor for your Robot
I've been working on an Infrared sensor to allow my rc car to detect obstacles and move to avoid them. I have had success using a design I found here at ikalogic.com, it's quite a complex design but it works well when completed.
I used a 555 timer chip to pulse my emitter LED on and off however I did not encounter the difficulty with over heating which is discussed in the article on ikalogic.com, my circuit seemed to have no problem running without the timer. I do not suggest you ignore it, I may have supplied less currant than they did so best to include it.
Parts needed to make an Infrared Proximity Sensor
- 2 x op-amps (I just got a single quad op-amp as it's more useful later)
- 4 x 1k resistors
- 1 x 50 ohm resistor
- 1 x 10 ohm resistor
- 1 x 2N2222A transistor
- 2 x Infrared LED's
- 1 x 10k variable resistor (you could get a few 47k resistors as they'll be handy for other testing)
- 1 x 555 timer chip
- You need a few capacitors for the timer two but I have to check the board at home to see what values they are. If your looking for the values send me an e-mail as I may have forgotten to update this page.
Testing the homemade Infrared Proximity Sensor
You can see a small video of the prototype being tested below. It used an Infrared transducer as a receiver and the result is a beam which detects objects around 25cm away.
Designing my own board for my autonomous car
Following this success I moved on to produce a board to use in the RC car. It is mostly based on the design from ikalogic however it uses a chip to control the timing of the IR sender. I found that the system did not seem to work consistently so I replaced the IR transducers with normal IR LEDs and this resolved the issue but reduced the signal distance to around 10cm. With this board I was able to do testing, I dismantled a second RC car to get a board which can send the signal from the RC car back to the computer. I connected these boards to my RC car and found that my signals interfered with each other, I then had to locate a third RC car to use as the base.