Newbe question - I'm thinking of creating a simple robot that heads to a signal source.

Ie, when you press a button on some remote control - the robot will head towards its source.

What would be the best choice of signal? A strength of a wifi, sound?


  • Will it have line-of-sight to the remote control? If so infrared (IR) would be my choice. You would have to place IR receivers all around the robot.
    – sa_leinad
    Oct 14, 2016 at 0:34

2 Answers 2


IR sensor in combination with an ultrasonic distance sensor would work great.

You can mimic a radar with an IR sensor so that it can detect from where the IR source from your remote is comming from. Then from there, process the angles and make you robot go towards it.

The ultrasonic distance sensor can be used a "fail" prevention system. In the sense that if it detects an object in front of the robot, it will stop, go around it and then continue towards the target


I like @Canadiancyborg's IR solution, but the same theory can be applied to any other emitter, and RF emitters may be preferable to an IR emitter since IR light can be blocked by intermediate objects. Also an omnidirectional RF transmitter is easier to arrange than an omnidirectional IR transmitter.

The basic theory is that you need to work out which direction a signal is coming from. In order to do that you need to "look around you" and find at which angle the signal is strongest.

A highly directional receiver (parabolic dish, IR receiver with lens, etc) will allow you to sense the signal strongest when the receiver is pointing directly at the source. By then rotating the receiver (either on its own independent rotational system, such as a servo motor, or by rotating the entire robot using the wheels) you can "lock on" to the direction where the signal is strongest and drive towards it.

  • Well RF is a little too powerful. My idea was to isolate the ir in something like a PVC pipe so it would detect the IR signal only at a specific angle. Otherwise, you can't really know where the target is.
    – Dat Ha
    Oct 14, 2016 at 13:55
  • @canadiancyborg RF doesn't need to be powerful - it all depends on the power of your transmitter, the sensitivity of your receiver, and the field of vision of your detector. Hence the parabolic dish (like a mini satellite dish). For IR you really want a lens to focus the receiver on a narrower point (the optical equivalent of a parabolic dish).
    – Majenko
    Oct 14, 2016 at 13:57

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