I was wondering If I could use an Arduino to find the direction of a vehicle using radio. I want the Arduino to find the orientation of the radio/where the object is detected (North, South, East, West) and activate a bit of code. Based on the orientation and if there is an object it will run a bit of code.

  • $\begingroup$ Have you tried searching for "RDF" (Radio Direction Finding) ? $\endgroup$ Commented Feb 5, 2020 at 11:40
  • $\begingroup$ If the radio is sending out position reports by APRS, it is pretty easy. $\endgroup$
    – Jon Custer
    Commented Feb 5, 2020 at 15:41
  • 3
    $\begingroup$ Hi Andrew! Your question is a bit too broadly stated. What does the vehicle do, i.e. does it transmit something specific? How far away is it? What equipment is OK to attach to the Arduino (for example, you could use the arduino as a shim so that the laptop that receives the video stream from a drone via Wifi and does optical object recognition, doesn't wobble; and that would still be "using an arduino")? $\endgroup$ Commented Feb 5, 2020 at 16:47
  • 2
    $\begingroup$ by the way, the title said "location", but your system description said "orientation", and that's not the same, so I changed the title of your question to fit the content. If that's not your intent, please don't hesitate to change that again! $\endgroup$ Commented Feb 5, 2020 at 21:11
  • 3
    $\begingroup$ I'm not sure if this is asking about the direction the vehicle is traveling, the direction the vehicle is oriented, or in what direction the vehicle is in relation to the arduino. Would you please edit to clarify? $\endgroup$ Commented Feb 5, 2020 at 22:06

2 Answers 2


I was wondering If I could use an Arduino to find the location of a vehicle using radio.

Radio is a pretty big topic, so yes, of course there are ways to use radio technologies to locate a vehicle. There are commercial solutions, but it could also be as simple as leaving a smartphone in the vehicle and using another phone to track it. Whether any of these make sense for your application is a different story, but here are some examples:

  • GPS: The Global Positioning System uses radio signals from an array of satellites to let receivers calculate their position. There are many GPS chips available that can interface with an Arduino, so if the goal is to know where the vehicle is while you're in it, that could work. It's also possible to connect an Arduino to a radio transmitter, so there are various ways that you could receive the location and then transmit it to receivers. One of those ways is...

  • APRS: Automatic Packet Reporting System is a widely-used scheme for transmitting position and other information through a network of nodes so that it can be recovered by anyone interested. Take a look at https://aprs.fi for more information.

  • RADAR: The term RADAR is an acronym for Radio Detection and Ranging -- you transmit a signal using radio waves, and then listen for any reflected signals. The orientation of the receiver and the delay between transmission and reception tell you the direction and distance of the thing that reflected the signal. You'll probably want something more capable than an Arduino for this application, but perhaps you could make it work for a very limited problem.

  • radio beacon: A simple transmitter that emits a periodic signal can be tracked by several receivers, and the position determined by triangulation.

I'm sure there are lots of other approaches as well. Your requirements aren't very clear, and without knowing more it's hard to point you in one direction. Here are some things you'll need to consider:

  • Do you want to track the vehicle's position inside the vehicle, or from some remote spot?
  • Do you have an amateur radio license?
  • Do you want to track the vehicle in an urban, suburban, or rural setting?
  • Do you have access to the vehicle, and if so can you install tracking hardware in it?
  • What's your budget?

You have two different use cases. Position reporting and direction finding.

Position reporting would be using something like APRS, Automatic packet reporting system. While APRS can transmit different types of data, it is most often used to report positions. A vehicle with a APRS radio will periodically send it position. with a receiver you can get the data.

You can see real time APRS data at web sites like https://www.aprsdirect.com/

With direction finding you use directional antennas to find the bearing to transmitter. Some antennas such as Yagis have lobes with higher gains in certain directions. You rotate the antenna until the signal is the strongest. Other antennas have a sharp null in one direction. You rotate the antenna until you lose the signal.

if you need a location instead of a direction, then you will have to get bearings from two different locations.

For more information on directional antennas do a search on "fox hunting" a popular radio competition.


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .