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Serial communication is used to transfer data between two devices.
Data passes between the computer and Arduino through the USB cable. Data is transmitted as zeros (‘0’) and ones (‘1’) sequentially.
Arduino dedicates Digital I/O pin # 0 to receiving and Digital I/O pin #1 to transmit.
For this reason, we typically do not use Digital I/O 0 or 1 for anything in our designs.
Serial Monitor & analogRead()
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