Troubleshooting

1. Code doesn't upload

Change the serial port by going to Tools > Serial Port > and try out any other COM #

Make sure the USB cable is securely connected to the board and the computer

2. Code uploaded but LED won't light

Make sure all other connections are securely and properly made as outlined in the diagram and tutorial

3. Check your wiring

Make sure that the breadboard is provided a +5V and ground from the arduino

Ensure that the diodes black strip is going towards the TIP31

Ensure your motors are properly soldered