IR Signal Plotter for IRremote & Arduino

We are delighted to present here a new sketch which implements a basic IR Signal plotter for IRremote. The sketch runs on an Arduino and makes use of the Serial Plotter feature of the Arduino IDE. Although there is no comparison to our powerful AnalysIR application, it may prove useful for beginners to get a quick overview of the shape of their IR remote signals.

Screenshot of IR Signal Plotter for IRremote
Screenshot of IR Signal Plotter for IRremote


Simply download the sketch and use the Arduino IDE to upload to your Arduino. The IR receiver is defaulted to digital pin 2 on the Arduino and you can change it to another pin, if desired. The serial port is set to operate at 115,200 bps. When you are ready to go, select the Serial plotter option from the tools menu on the Arduino IDE, select the correct port number & BAUD rate for your Arduino and then simply press a button on your remote and the plotter will be updated automatically for every signal captured by IRremote. You will also require the IRremote library installed in your Arduino IDE. (We assume users are familiar with Arduino, the Arduino IDE & IRremote.)


The Serial plotter is quite limited by design and provides only 500 display points across the X-axis. The sketch automatically scales every signal to fit into the full window width. However, some longer signals will not fit into the window and will scroll out to the left (or be compressed tightly), before you get to study them. Some remotes will send multiple signals for every press of a button or if you keep the button pressed. In this situation you will likely only see the last chunk of the signal.

IR Signal Plotter for IRremote & Arduino

Source Code of Sketch

The source code of the sketch can be downloaded here. The file is in text format and the contents should be copied and pasted to a new sketch in the Arduino IDE. If you nee support go to our IRforum.

Other Platforms

The sketch was designed for the Arduino UNO using the Arduino IDE & Serial Plotter along with IRremote. We tested with the UNO using our A.IR Shield Rx (Infrared receiver module). It should also work with little or no modification on most other Arduino platforms that are supported by the IDE and IRremote. You can use any standard IR receiver.

Power Users

The sketch provides basic, but useful, plotting of IR remote control signals as pictured above. More advanced users may prefer to pick up a copy of our AnalysIR application from our webshop along with our range of advanced IR modules. AnalysIR is the leading tool for the analysis, decoding, playback & reverse engineering of Infrared remote control signals and protocols.

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