Arduino Nano 33 BLE Rev2

Arduino Nano 33 BLE Rev 2 is based on the Nordic nRF52840 SoC, featuring a 32-bit ARM Cortex-M4F core running at 64 MHz. It integrates Bluetooth Low Energy (BLE) connectivity and exposes multiple GPIO pins through Nano-style headers.

Official Pinout

Power management & low power modes

The board is designed for battery-operated efficiency, but it requires careful jumper management on the bottom of the PCB.

• VIN Pin: Accepts 5V to 18V. If used, it automatically disconnects the USB power source.
• 3.3V Pin: Output from the onboard regulator.
  • Ultra-Low Power Hack: To bypass the regulator and save every micro-amp, you can cut the 3V3 jumper on the back and power the board directly with a 3.3V battery.
• 5V Pin: By default, this pin is inactive. To output 5V (from USB or VIN), you must short the VUSB jumper on the back.
• LED ON: A power indicator tied to the 5V rail (USB or VIN).

Digital & PWM pins

All 14 digital pins (D0–D13) can be used for general input and output.

• PWM: Unlike the standard Nano, all digital pins on the Nano 33 BLE can support PWM (Pulse Width Modulation).
• Logic Level: Strictly 3.3V. Connecting a 5V sensor signal directly to these pins will likely fry the microcontroller.

Analog pins

There are 8 analog input pins (A0–A7).

• Resolution: While the standard Arduino uses 10-bit resolution, this board supports up to 12-bit resolution, providing a range of 0 to 4095.
• A4 (SDA) and A5 (SCL): These are specifically assigned for I2C communication.

Communication interfaces

The Nano 33 BLE is one of the few boards that can act as both a Bluetooth® Client and Host.

Interface	Pins	Specialized Notes
I2C	A4 (SDA), A5 (SCL)	Warning: These have internal pull-up resistors. Usage as analog inputs is NOT recommended.
NFC	D7 & D8	You can attach an external NFC antenna here to emulate an NFC tag.
UART	D0 (RX), D1 (TX)	Dedicated hardware serial for high-speed communication.
SPI	D11 (COPI), D12 (CIPO), D13 (SCK)	Standard SPI for peripheral displays or SD cards.

Onboard sensors & internal pins

The “Sense” version of this board includes a suite of sensors, but even the standard BLE version has internal connections you should know:

• Built-in LED: Connected to D13.
• RGB LED: This is a common-anode LED. To turn a color on, you must write the pin LOW.
  • Red: LEDR
  • Green: LEDG
  • Blue: LEDB
• I2C Bus: The onboard IMU (Inertial Measurement Unit) is connected to the same I2C bus as A4/A5.

Specifications

Feature	Specification
Microcontroller	nRF52840 (32-bit ARM® Cortex®-M4)
Operating Voltage	3.3V (Not 5V tolerant)
Input Voltage (Limit)	5V – 21V (Nominal: 5V – 18V)
Clock Speed	64 MHz
Flash Memory	1 MB
SRAM	256 KB
Digital I/O Pins	14 (All can be used for PWM & Interrupts)
Analog Input Pins	8 (12-bit resolution ADC)
DC Current per I/O Pin	10 mA – 15 mA (Conservative limit)
Bluetooth	Bluetooth® Low Energy 5.0 (NINA-B306 module)
IMU (9-axis)	BMI270 (6-axis) + BMM150 (3-axis Magnetometer)
USB Connector	Micro USB
Interfaces	UART, SPI, I2C
Board Dimensions	45 mm x 18 mm

Important usage notes

• 3.3V Limit: The pins are not 5V tolerant. 5V signals will damage the board.
• New IMU Library: Rev 2 uses the BMI270 (6-axis) and BMM150 (3-axis) sensors. You must use the Arduino_BMI270_BMM150 library instead of the old LSM9DS1 library.
• VUSB Jumper: The solder bridge to enable 5V on the VUSB pin has moved to the top side of the board for easier access.
• Improved Power: It uses a new step-down converter (MP2322), which is more efficient but retains the same voltage limits.
• Double-Tap Reset: If the board is “bricked” or won’t upload, quickly double-tap the reset button to enter bootloader mode.
• BLE Only: It supports Bluetooth Low Energy 5.0; it is not compatible with “Classic” Bluetooth (BT 2.0/3.0).
• RGB LED: The onboard LED is “Active Low”—writing LOW turns it ON, and HIGH turns it OFF.
• MicroPython Support: The Rev 2 is fully compatible with MicroPython if you prefer it over C++.

Helpful resources