Beetle CM-32U4 Compatible with Arduino Leonardo - ATmega32U4 Wiki - DFRobot



Beetle CM-32U4, an upgraded version of DFRobot Beetle Board, adds a charge management function while retaining the original advantages like rich functions and small size. Users can use the battery pack to power the project or charge the battery via USB, which can greatly increase the service life when using this little board in "one-off" compact projects. There are 3 power supply methods: USB power supply; Battery pack power supply on the BAT pin; 5V external power supply on the VIN pin. Features like compact size, being rechargeable and diverse power supplies make this board more widely applicable to DIY projects, workshops, gift projects, E-Textiles wearable, and educational.

Beetle CM-32U4 is fully compatible with Arduino, please select “Arduino Leonardo” when using.




Board Overview



Board Selection


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Indicator Status description

Status Power Indicator(red) LED Light(blue) Charging Indicator(green)
OFF Mainboard Power off Can be set Fully charged
ON Mainboard Power on Can be set Charging
Flash Burning Codes/Resetting Resetting/can be set No battery

Introduction of Charging Process

Prepare a 1000mAh lithium battery. Connect the positive of the battery to BAT on the Beetle CM-32U4 and the negative to GND, and then connect to the USB charging cable.


At this time, the BAT port will charge the battery with an input current of 200mA~600mA and the green charging light will present the current status of the battery:

Status Charging Indicator(green)
OFF Fully charged
ON Charging
Flash No battery

Introduction of Resetting



NOTE: Only the red power indicator and blue indicator will be affected during the RST process.

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