While trying to upload code from the Arduino IDE to my EL Sequencer I encountered the error message, "avrdude: stk500_getsync(): not in sync: resp=0x00".
- Set board and port (there is ample documentation about this).
- Enable verbose output during upload (hold down the shift key while clicking on the upload button in toolbar. There is also a checkbox setting in preferences)
- From the verbose output I observed the IDE was Sending data but the board was not Receiving it.
- I resoldered the Receive header pin on the El Sequencer used to connect the FTDI cable/breakout board.
- Voila! Program uploaded successfully.
Hope this helps.