Arduino remote IRsend undefined reference error
It looks like you have IRSend installed wrong.
Did you follow the instructions from the homepage?


Navigate to the Releases page.

Download the latest release.

Extract the zip file

Move the &quot;IRremote&quot; folder that has been extracted to your libraries directory.

Make sure to delete Arduino_Root/libraries/RobotIRremote. Where Arduino_Root refers to the install directory of Arduino. The library RobotIRremote has similar definitions to IRremote and causes errors.



Number 5 looks like a good candidate for the cause of your trouble.