ESP32-C2

[中文]

Note

This document is automatically translated using AI. Please excuse any detailed errors. The official English version is still in progress.

ESP32-C2 Chip/Module Startup Conditions

The operating voltage range of the ESP32-C2 chip is 3.0 V ~ 3.6 V; when using a single power supply, it is recommended that the power supply voltage for the ESP32-C2 series chip be 3.3 V, with a rated output current ideally at 500 mA or above. The operating voltage range of the ESP32-C2 module is 3.0 V ~ 3.6 V; when using a single power supply, it is recommended that the power supply voltage for the ESP32-C2 series chip be 3.3 V, with a rated output current ideally at 500 mA or above. The CHIP_PU (EN) pin of the ESP32-C2 is the chip’s startup pin. When CHIP_PU (EN) is at a high level, the chip is enabled; when it is at a low level, the chip is turned off. Note: The CHIP_PU pin should not be left floating. When the ESP32-C2 is powered by a 3.3V system power supply, the CHIP_PU (EN) pin must be at a high level.

Hardware Connection

The ESP32-C2 firmware is downloaded by default through UART0 (i.e., TXD0 (GPIO20) and RXD0 (GPIO19)).

When downloading firmware based on the ESP32-C2 Module, users need to prepare:

  • 3.3V Power Supply

  • Serial Debugging Tool

  • Dupont wire

Proceed with the wiring as follows to meet the hardware requirements for chip power supply, power-on startup, and entering download mode.

ESP32-C2

3.3V External Power Supply

Serial debugging tool

3V3

VDD

GND

GND

GND

EN

VDD

GPIO8 (pull-up, default is floating)

VDD

GPIO9 (Pull down, default is weak pull-up)

GND

TXD0（GPIO20）

RXD

RXD0（GPIO19）

TXD

Chip Power-On Startup Log

After powering on the ESP32-C2 chip/module, you can use the PC-side serial debugging software to view the UART0 serial output during chip power-up to confirm whether the chip has entered download mode. If the chip powers up and enters download mode, UART0 will print the following log:

ESP-ROM:esp32c2-eco4-20240515
Build:May 15 2024
rst:0x1 (POWERON),boot:0x4 (DOWNLOAD(UART0))
waiting for download

Note

After powering on the ESP32-C2 chip/module, if you do not see the log printing, you can trigger the log printing by pulling down and then pulling up the CHIP_PU (EN) pin for a hardware reset restart.

In terms of software, Espressif provides a PC-based Flash download tool, which can directly download firmware (.bin) into Flash. For usage instructions, refer to the Flash Download Tool User Guide.

After the firmware download is complete, if you want to run the burned firmware, you can pull up GPIO9 (default is high level) based on the above hardware wiring, and then pull down and pull up the CHIP_PU (EN) pin for hardware reset and restart, to make the chip re-enter the Flash boot mode. Finally, use the serial debugging software to view the UART0 log printout, to check the firmware running status.

Note

  • Upon power-up of the chip, both GPIO8 and GPIO9 cannot be at a low level simultaneously.

When testing with the ESP32-C2 Development Board, you can directly use a USB Type-C cable to connect to the UART or USB interface on the development board for firmware download. If you are using the USB interface for firmware download for the first time, you need to manually pull down the GPIO9 pin, that is, hold down the Boot button and then power up to manually enter the download mode.

Reference

Summary of Hardware Wiring Principles:

Official Documentation: