Power Pins
- 5V –> Directly connected to the USB input port. It provides the voltage (5V) and current output capacity of the connected USB power source. It is recommended to use a power source between 500 mA and 1000 mA. It can be used to power externally connected units.
- 3V3 –> Provides a 3.3V voltage and up to 1A current output through a DC-DC step-down regulator. It can be used to power externally connected units.
- EN –> This pin must be held at logic “1” (3.3V) level to enable operation of the ESP32-S2 microcontroller. This is ensured by an internally placed pull-up resistor. The “RES” button is connected to this pin and is used to reset the system. When the button is pressed, the EN pin is pulled to logic “0” (0V) level.
- GND –> Common ground line of the circuit for all power and logic connection pins.
Logic Pins (Input/Output Pins)
- D0 – D13 –> Used as digital input/output pins. Logic “0” corresponds to 0V; logic “1” corresponds to 3.3V voltage level. All of these pins can be used as PWM pins. The pins are not 5V tolerant.
Analog Pins
- A0 – A6 –> Used as input pins for analog signals in the range of 0V – 3.3V. All of these pins can also be used as digital input/output pins.
- DA0 – DA1 –> Used to provide analog signal output in the range of 0V – 3.3V. They can also be used as digital input/output pins. They are respectively connected to D12 and D11 pins.
Communication Pins
- TX – RX –> Serial communication (UART) pins. Firmware upload and terminal communication are performed through these pins. TX is the output pin, while RX is the input pin. Besides UART communication, they can also be used as digital input/output pins. They are also referred to as D1 (TX) and D0 (RX).
- I2C –> SDA and SCL pins can be used to control any sensor or actuator. SDA (input/output) is the data line; SCL (output) is the clock (timing) synchronization pin. These pins are held at logic “1” (3.3V) level with 10K pull-up resistors. Besides I2C communication, they can also be used as digital input/output pins. They are also connected to D8 (SDA) and D7 (SCL) pins.
- SPI –> MOSI, MISO, SCLK, and SS* pins can be used to control any sensor or actuator. MOSI (output) is the data pin, MISO (input) is the data pin, SCLK (output) is the clock (timing) synchronization pin, and SS is the slave select pin. These pins can also be used as digital input/output pins. They are also referred to as SS (D10), SCLK (D6), MISO (D5), and MOSI (D4).
PWM Pins
- PWM –> PWM0 and PWM1 are pulse-width modulation (PWM) square wave output pins. They are also connected to D2 and D3 pins and can be used as digital input/output pins.
- All digital input/output pins (D0–D13) can be used as PWM pins.
Capacitive Touch Pins
- T0 – T8 –> Input pins used for capacitive touch sensing. They are also connected to T0 (A0), T1 (A1), T2 (A2), T3 (A3), T4 (A4), and T5 (A5) pins and can be used as digital input/output pins.
RGB Pins
- LEDR –> Pin connected to the internal red LED; external connection is not available.
- LEDG –> Pin connected to the internal green LED; external connection is not available.
- LEDB –> Pin connected to the internal blue LED; external connection is not available.
Button Pin
- GPKEY –> Pin connected to the internal general-purpose button. It is also used to put the system into manual upload mode. It is held at logic “1” (3.3V) level with a 10K pull-up resistor. It is also connected to D13 pin and can be used as a digital input/output pin.
Programming Pins
- EN –> This pin must be held at logic “1” (3.3V) level to enable operation of the ESP32-S2 microcontroller. This is ensured by an internally placed pull-up resistor. The “RES” button is connected to this pin and is used to reset the system. When the button is pressed, the EN pin is pulled to logic “0” (0V) level.
- BOOT –> Used to put the system into manual upload mode. It is the pin to which the internal general-purpose button (BUT) is connected. It is held at logic “1” (3.3V) level with a 10K pull-up resistor. It is also connected to D13 pin.