Thank you for your information! I thought I selected Arduino Uno, but actually not.. I selected it and now I can compile testBuzzer.ino. When I upload it, buzzer sound one or two times, but stopped.. Output of Arduino IDE is here. 0 1 if (you cannot see this sentence on serial monitor) there's something wrong with your Arduino IDE's configuration. 0 1 if (you cannot see this sentence on serial monitor) there's something wrong with your Arduino IDE's configuration. 0 1

I have a pre-assembled Bittle, but my friend has not assembled one, and is trying hard to put the spring in, but failed. Could somebody take a movie to understand how to do dental floss trick? I could not understand how to use dental floss for this from the explanation.. Maybe a photo image will be helpful to understand... I suppose dental floss is a thread. Loop it around one or two turns at the end of the spring you are putting in last and feed the ends of the floss through the hole in the leg.