* '''GND''': Common ground between logic and power.
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* '''Vin''': Power In 3.3 to 6V. The board regulated it to 3.3V. '''Be sure you can supply up to 150mA''' on this pin since Radio Emitting can reach this current level.
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* '''EN''': Enbable Pin used to switch off the Power supply (and the radio module). EN use a pull-up resistor to maintain the regulator enabled, just pull it down to switch off the radio.