This user guide shows how to get started with the ESP32-PICO-KIT V4 / V4.1 mini development board. For description of other versions of the ESP32-PICO-KIT check :doc:`../hw-reference/index`.
..note::
This particular description covers ESP32-PICO-KIT V4 and V4.1. The difference is USB-UART bridge that has been changed from CP2102 in V4 to CP2102N in V4.1. The first provides up to 1 Mbps transfer rates, while the later up to 3 Mbps transfer rates.
ESP32-PICO-KIT 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 modules, 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, a 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 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`_.
Standard ESP32-PICO-D4 module soldered to the ESP32-PICO-KIT 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.
A single chip USB-UART bridge: CP2102 in V4 of the board and CP2102N in V4.1. The first provides up to 1 Mbps transfer rates, while the latter up to 3 Mbps transfers rates.
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`_.
BOOT Button
Holding down the Boot button and pressing the EN button initiates the firmware download mode. Then user can download firmware through the serial port.
EN Button
Reset button; pressing this button resets the system.
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.
To start development of applications, proceed to section :doc:`index`, that will walk you through the following steps:
*:ref:`get-started-setup-toolchain` in your PC to develop applications for ESP32 in C language
*:ref:`get-started-connect` the module to the PC and verify if it is accessible
*:ref:`get-started-build-flash` an example application to the ESP32
*:ref:`get-started-build-monitor` instantly what the application is doing
Pin Descriptions
----------------
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.
