Power Pins
- 5V → Directly connected to the USB input port. It provides the voltage (5V) and current capability of the connected USB power source. A power source between 500 mA and 1000 mA is recommended. It can be used to power externally connected units.
- 3V3 → Provides a 3.3V voltage and up to 1A current output via a DC-DC step-down converter. It can be used to power externally connected units.
- EN → This pin must be held at logic “1” (3.3V) to enable the operation of the ESP32-S2 microcontroller. This condition 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).
- GND → Common ground line of the circuit for all power and logic connection pins.
Logic Pins (Input/Output Pins)
- D0 – D12 → Used as digital input/output pins. Logic “0” corresponds to 0V, and logic “1” corresponds to 3.3V. 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 connected to D12 (DA0) and D11 (DA1) respectively.
Communication Pins
- TX – RX → Serial communication (UART) pins. Firmware uploading and terminal communication are carried out through these pins. TX is the output pin and 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 → Sensors or actuators can be controlled via the SDA and SCL pins. SDA is the bidirectional data line, and SCL is the output clock (timing) line. These pins are held at logic “1” (3.3V) level with 10K pull-up resistors. In addition to I2C communication, they can also be used as digital input/output pins. They are connected to D8 (SDA) and D7 (SCL).
- SPI → Sensors or actuators can be controlled via the MOSI, MISO, SCLK, and SS* pins. MOSI (output) is the data pin, MISO (input) is the data pin, SCLK (output) is the clock 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–D12) can be used as PWM pins.
Capacitive Touch Sensor Pins
- T0 – T6 → Input pins used for capacitive touch sensing. They are connected respectively to T0 (A0), T1 (A1), T2 (A2), T3 (A3), T4 (A4), T5 (A5), and T6 (A6) pins, and can also be used as digital input/output pins.
RGB Pin
- RGBLED → The pin to which the onboard addressable RGB LED is connected. It is not exposed externally through pins. It is also referred to as D14.
Button Pin
- GPKEY → The pin connected to the onboard general-purpose button. It is also used to place the system into manual boot (upload) mode. It is held at logic “1” (3.3V) level with a 10K pull-up resistor. It is also connected to D13 and can be used as a digital input/output pin.
Programming Pins
- EN → This pin must be held at logic “1” (3.3V) to enable the operation of the ESP32-S2 microcontroller. This condition is ensured by an internal 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).
- BOOT → Used to place the system into manual boot (upload) mode. It is the pin connected to the onboard general-purpose button (BUT). It is held at logic “1” (3.3V) level with a 10K pull-up resistor. It is also connected to D13.