Hi!Could you be more specific on your problem? When building mine I prototyped the circuits using an Arduino UNO, when I was sure I had the code correct I downloaded the code onto a pro mini. I highly recommend you do the same!Pro minis need an FTDI to USB adapter to download the code onto them. ( I will add this component to the parts list!) When using the pro minis make sure you have selected the right kind of board (Tools > Board > Arduino Pro Mini) and com port from the Arduino software. Cheers.