Let's Make Robots!

Edge Detection

Possibly helps to detect objects, walls and holes.
 Some fancy nice ultrasonic sensors can read multiple echoes of sent ultrasonic wave. Cheap senosrs register the first echo that arrived back. If we could listen … Read more

LDR vs Ir Phototransistor

Hi  Everyone

I'm doing research for my first bot from scratch. I was hoping someone could point me to a good source of info on the advatages/disavantages of using LED & LDR vs Ir with Phototransistor for proximity sensors.

My basic goal for them is to have an edge detector in each corner and a line following array. I thought the LDRs would a simple and cheap approach but was surprised to see how cheap this Ir LED & Phototrasistor set was.

Edge Detection

I've noticed a lot of robots with edge detection, to prevent them falling off edges (obviously).

I'm curious as to the type of sensor used for this. I'm assuming it's IR, but are people using an off the peg sensor, or making their own?


The Bromz.