This user guide shows how to get started with the ESP32-PICO-KIT V4 mini development board. For description of other versions of the ESP32-PICO-KIT check :doc:`../hw-reference/index`.
ESP32-PICO-KIT V4 is a mini development board produced by `Espressif <https://espressif.com>`_. At the core of this board is the ESP32-PICO-D4, a System-in-Package (SIP) module with complete Wi-Fi and Bluetooth functionalities. Comparing to other ESP32 chips, the ESP32-PICO-D4 integrates several peripheral components in one single package, that otherwise would need to be installed separately. This includes a 40 MHz crystal oscillator, 4 MB flash, filter capacitors and RF matching links in. This greatly reduces quantity and costs of additional components, subsequent assembly and testing cost, as well as overall product complexity.
The development board integrates a USB-UART Bridge circuit, allowing the developers to connect the board to a PC's USB port for downloads and debugging.
For easy interfacing, all the IO signals and system power on ESP32-PICO-D4 are led out through two rows of 20 x 0.1" pitch header pads on both sides of the development board. To make the ESP32-PICO-KIT V4 fit into mini breadboards, the header pads are populated with two rows of 17 pin headers. Remaining 2 x 3 pads grouped on each side of the board besides the antenna are not populated. The remaining 2 x 3 pin headers may be soldered later by the user.
The 2 x 3 pads not populated with pin headers are internally connected to the flash memory embedded in the ESP32-PICO-D4 SIP module. For more details see module's datasheet in `Related Documents`_.
The board dimensions are 52 x 20.3 x 10 mm (2.1" x 0.8" x 0.4"), see section `Board Dimensions`_. An overview functional block diagram is shown below.
Standard ESP32-PICO-D4 module soldered to the ESP32-PICO-KIT V4 board. The complete system of the ESP32 chip has been integrated into the SIP module, requiring only external antenna with LC matching network, decoupling capacitors and pull-up resistors for EN signals to function properly.
This light emitting diode lits when the USB or an external 5V power supply is applied to the board. For details see schematic in `Related Documents`_.
I/O
All the pins on ESP32-PICO-D4 are broken out to the pin headers on the board. Users can program ESP32 to enable multiple functions such as PWM, ADC, DAC, I2C, I2S, SPI, etc. For details please see section `Pin Descriptions`_.
There following options are available to provide power supply to the ESP32-PICO-KIT V4:
1. Micro USB port, this is default power supply connection
2. 5V / GND header pins
3. 3V3 / GND header pins
..warning::
Above options are mutually exclusive, i.e. the power supply may be provided using only one of the above options. Attempt to power the board using more than one connection at a time may damage the board and/or the power supply source.
The two tables below provide the **Name** and **Function** of I/O headers on both sides of the board, see :ref:`get-started-pico-kit-v4-board-front`. The pin numbering and header names are the same as on a schematic in `Related Documents`_.
4. This pin is connected to the pin of the USB bridge chip on the board.
5. The operating voltage of ESP32-PICO-KIT’s embedded SPI flash is 3.3V. Therefore, the strapping pin MTDI should hold bit ”0” during the module power-on reset.
