Hello friends! Today we will troubleshoot the “Failed, response timed out” message that can appear while using an nRF24L01 or nRF24L01+ radio with Arduino. We will work through the local SPI connection, radio settings, power supply and the reply expected by the example program. The original experiment on this page improved after adding a 100-microfarad capacitor across the radio supply. That is useful experience to retain, but it is not a universal diagnosis. A timeout reports a missing event; it does not identify the reason that event was missing. If you are wiring the radios for the first time, begin with our nRF24L01 and Arduino interfacing tutorial . Here, we will concentrate on finding faults systematically rather than changing several settings until the link happens to work. Figure: ...