Data Sheet

External(non‐USB)powercancomeeitherfromaDCpowersupplyorbattery.
LeadsfromabatteryorDCpowersupplycanbeconnectedtotheGndandVin
pins.
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Theboardcanoperateonanexternalsupplyof6to20volts.Ifsuppliedwithless
than7V,however,the5Vpinmaysupplylessthanfivevoltsandtheboardmay
becomeunstable.Ifusingmorethan12V,thevoltageregulatormayoverheatand
damagetheboard.Therecommendedrangeis7to12volts.
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Thepowerpinsareasfollows:
 VI.TheinputvoltagetotheMICROboardwhenit'susinganexternalpowersource
(asopposedto5voltsfromtheUSBconnectionorotherregulatedpowersource).
Youcansupplyvoltagethroughthispin.
 5V.Theregulatedpowersupplyusedtopowerthemicrocontrollerandother
componentsontheboard.ThiscancomeeitherfromVINviaanon‐board
regulator,orbesuppliedbyUSBoranotherregulated5Vsupply.
 3V.A3.3voltsupplygeneratedbytheon‐boardregulator.Maximumcurrentdraw
is50mA.
 GND.Groundpins.
Memory
TheATmega32U4has32KB(with4KBusedforthebootloader).Italsohas2.5KB
ofSRAMand1KBofEEPROM(whichcanbereadandwrittenwiththeEEPROM
library).https://www.arduino.cc/en/Main/en/Reference/EEPROM
InputandOutput
SeethemappingbetweenArduinopinsandATmega32U4ports,andthePin
MappingoftheArduinoMicro:

nomebottone
https://www.arduino.cc/en/Hacking/PinMapping32u4
nomebottone
https://www.arduino.cc/en/uploads/Main/ArduinoMicro_Pinout3.png

Eachofthe20digital i/opinsontheMicrocanbeusedasaninputoroutput,
usingpinMode(),digitalWrite(),anddigitalRead()functions.Theyoperateat5
volts.Eachpincanprovideorreceive20mAasrecommendedoperatingcondition
andhasaninternalpull‐upresistor(disconnectedbydefault)of20‐50kohm.A
maximumof40mAisthevaluethatmustnotbeexceededtoavoidpermanent
damagetothemicrocontroller.
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