Esp32 DevKitC V4

Espressif ESP32 DevKitC V4 also integrates a wealth of peripherals, including capacitive touch sensors, Hall sensors, low-noise sense amplifiers, SD card interface, Ethernet interface, high-speed SDIO/SPI, UART, I2S and I2C, etc. The ESP32 DevKitC V4 development board is powerful and versatile, and can be used for low-power sensor networks and demanding tasks such as speech encoding, audio streaming and MP3 decoding.

The main components, interfaces and control methods of the ESP32 DevKitC V4 development board are as follows:

ESP32 DevKitC V4 development board (onboard ESP32-WROOM-32 module)

ESP32 DevKitC V4 datasheet

main components	basic introduction
ESP32-WROOM-32	ESP32 based modules. For more details, please refer to “ESP32-WROOM-32 Technical Specifications”.
EN	The ESP32 DevKitC V4 reset button can reset the system.
Boot	Download button. Press and hold the Boot button, and at the same time press the EN button (do not release the Boot button at this time) to enter the “firmware download” mode, and download the firmware through the serial port.
USB-to-UART bridge	Single-chip USB-UART bridge that provides transfer rates up to 3 Mbps.
Micro USB interface	The USB interface can be used as a power supply for the circuit board, or as a communication interface between a PC and the ESP32-WROOM-32 module.
5V Power On ESP32 DevKitC V4 onboard LED	This LED will be on when the board is powered (USB or external 5 V). For more information, see the schematic in the related documentation.
I/O connector	Most of the pins of the modules on the board have been LED out to the pin headers of the development board. Users can program ESP32 to realize PWM, ESP32 DevKitC V4 adc, DAC, I2C, I2S, ESP32 DevKitC V4 spi and other functions.

ESP32 DevKitC V4 power supply options

The ESP32 DevKitC V4 can choose one of the following three power supply methods:

Micro USB powered (default)

5V / GND pin power supply

3V3 / GND pin power supply

Warn:

The above ESP32 DevKitC V4 power supply modes cannot be connected at the same time, otherwise the development board and/or power supply may be damaged.

Module interface	ESP32 DevKitC V4 sd card, ESP32 DevKitC V4 UART, ESP32 DevKitC V4 SPI, SDIO, ESP32 DevKitC V4 12C, LED PWM, motor PWM, ESP32 DevKitC V4 12S, IR. Pulse counter, GPIO, capacitive touch sensor, ESP32 DevKitC V4 ADC, DAC, 2-wire auto Interface (TWAIR), compatible with ISO11898-1 protocol (CAN specification 2.0)
On-chip sensor	Hall sensor
Integrated vibration	40MHZ crystal oscillator
Integrated SPI flash 1	4 MB
Working voltage/supply voltage	3.0V~3.6v
Working current	Average: 80mA
supply current	Minimum: 500mA
Recommended working environment temperature range	-40 °C～+85°℃

ESP32 DevKitC V4 Development board size

The table below lists the names and functions of the ESP32 DevKitC V4 pins (J2 and J3) on both sides of the development board

J2:

J3

J3

1(1,2)

P: Power; I: Input; O: Output.

2(1,2,3,4,5,6)

ESP32 DevKitC V4 pins D0, D1, D2, D3, CMD, and CLK are used for internal communication between the ESP32 chip and the SPI flash, and are concentrated on both sides of the ESP32 DevKitC V4 development board near the USB port. Generally speaking, it is best not to connect these pins, otherwise it may affect the work of ESP32 DevKitC V4 SPI flash / ESP32 DevKitC V4 SPI RAM.

3(1,2)

Pins GPIO16 and GPIO17 are only applicable to onboard ESP32-WROOM series and ESP32-SOLO-1 development boards, and pins GPIO16 and GPIO17 onboard ESP32-WROVER series development boards are reserved for internal use.

The ESP32 chip has 34 physical ESP32 DevKitC V4 GPIO pads. Each pad can be used as a general-purpose IO, or connected to an internal peripheral signal. The IO_MUX, RTCIO_MUX, and GPIO switch matrix are used to route signals from peripherals to GPIO pads. These modules together form the IO control of the chip. Each pad has utilization functions, refer to the attached IO_MUX Pad list and RTC pins and corresponding GPIO pads.

GPIO can be configured as ordinary input and output, but it cannot or is not recommended to use this GPIO due to function multiplexing and hardware limitations

Input-only ESP32 DevKitC V4 pins

GPIO34 to 39 are input-only pins. These ESP32 DevKitC V4 pins have no internal pull-up or pull-down resistors.
GPIO34
GPIO35
GPIO36
GPIO39

ESP32 DevKitC V4 spi flash GPIO6 to GPIO11 integrated on ESP32 DevKitC V4 esp-wroom-32 are exposed in some ESP32 dev boards. However, these pins connect to the integrated SPI flash on the ESP32 DevKitC V4 esp-wroom-32 chip and are not recommended for other uses. So, don’t use these pins in your project.
GPIO6 (SCK/CLK)

GPIO7 (SDO/SD0)

GPIO8 (SDI/SD1)

GPIO9 (SHD/SD2)

GPIO10 (SWP/SD3)

GPIO11 (SCS/CMD)

Capacitive touch GPIO

ESP32 has 10 internal capacitive touch sensors. They can sense changes in any charged substance. Therefore, they can detect changes caused by touching the ESP32 DevKitC V4 GPIO with a finger. Capacitive pins can also be used to wake ESP32 DevKitC V4 deep sleep.

GPIO4 (T0)

GPIO0 (T1)

GPIO2 (T2)

GPIO15 (T3)

GPIO13 (T4)

GPIO12 (T5)

GPIO14 (T6)

GPIO27 (T7)

GPIO33 (T8)

GPIO32 (T9)

Analog-to-Digital Converter (ADC)

ESP32 has 18 X 12 bit ESP32 DevKitC V4 ADC input channels (while ESP8266 has only 1 X 10 bit ADC). These are the GPIOs that can be used as ESP32 DevKitC V4 ADC and corresponding channels.

GPIO36 (ADC1_CH0)

GPIO37 (ACD1_CH1)

GPIO38 (ADC1_CH2)

GPIO39 (ADC1_CH3)

GPIO32 (ADC1_CH4)

GPIO33 (ADC1_CH5)

GPIO34 (ADC1_CH6)

GPIO35 (ADC1_CH7)

GPIO4 (ADC2_CHO)

GPIO3 (ADC2_CH1)

GPI02(ADC2_CH2)

GPI015 (ADC2_CH3)

GPI013 (ADC2_CH4)

GPI012 (ADC2_CH5)

GPI014 (ADC2_CH6)

GPI027 (ADC2_CH7)

GPIO25 (ADC2_CH8)

GPIO26 (ADC2_CH9)

Digital to Analog Converter (DAC)

There are 2 X 8-bit DAC channels on espressif ESP32 DevKitC V4, which are used to convert digital signals into analog voltage signal output.

GPIO25 (DAC1)

GPIO26 (DAC2)

RTC GPIO

espressif ESP32 DevKitC V4 supports RTC GPIO. When it is in ESP32 DevKitC V4 deep sleep, the GPIOs routed to the RTC low power subsystem can be used. These RTC GPIOs can be used to wake up it from ESP32 DevKitC V4 deep sleep while the Ultra Low Power (ULP) processor is running.

GPIO36 (RTC_GPIO0)

GPIO39 (RTC_GPIO3)

GPIO34 (RTC_GPIO4)

GPIO35 (RTC_GPIO5)

GPI025 (RTC_GPIO6)

GPI026 (RTC_GPIO7)

GPIO33 (RTC_GPIO8)

GPIO32 (RTC_GPIO9)

GPIO4 (RTC_GPIO10)

GPIO8 (RTC_GPIO11)

GPIO2 (RTC_GPIO12)

GPIO15 (RTC_GPIO13)

GPI013 (RTC_GPIO14)

GPI012 (RTC_GPIO15)

GPI014 (RTC_GPIO16)

GPI027 (RTC_GPIO17)

Pulse width modulation

The ESP32 DevKitC V4 LED PWM controller has 16 independent channels that can be configured to generate PWM signals with different characteristics. All ESP32 DevKitC V4 pins that can be output can be used as PWM pins (GPIO34-39 cannot generate PWM).

ESP32 DevKitC V4 I2C pins

ESP32 DevKitC V4 has two I2C channels, any pin can be set as SDA or SCL.

GPIO21 (SDA)

GPIO22 (SCL)

ESP32 DevKitC V4 SPI pins

SPI and GPIO Mapping

GPIO23(VSPI_MOSI)

GPIO19 (VSPI_MISO)

GPIO18 (VSPI_CLK)

GPIO5 (VSPI_CS)

GPIO13 (HSPI_MOS1)

GPIO12 (HSPI_MISO)

GPIO14 (HSPI_CLK)

GPIO15 (HSPI_CS)

Interrupt

All GPIOs can be configured as interrupts

Strapping pins

The ESP32 chip has the following Strapping pins:

GPIO0

GPIO2

GPIO4

GPIO5 (must be high during startup)

GPIO12 (must be low during startup)

GPIO15 (must be high during startup)

Pins HIGH at Boot

Some ESP32 DevKitC V4 GPIOs change their state to high or output a PWM signal when ESP32 DevKitC V4 reset is initiated. This means that if the outputs are connected to these GPIOS, you may get unexpected results when the ESP32 DevKitC V4 reset or boots:

GPIO1

GPIO3

GPIO5

GPIO5-11

GPIO14

GPIO15 Enable (EN)

Enable (EN)

Enable (EN) is the enable pin for the 3.3V regulator. It’s pulled up, so connect to ground to disable the 3.3V regulator. This means, for example, that this pin can be used to connect to a button to reboot the ESP32 DevKitC V4.

Attached picture:

This Table 19 lists the RTC pins and the corresponding ESP32 DevKitC V4 GPIO pad.