# Heltec ESP32-C3 Arduino Development Board > Ultra-compact RISC-V development board with ESP32-C3FN4, WiFi, BLE 5.0, integrated battery management, and USB-C — ideal for low-power IoT sensor nodes and wireless prototyping. ## Quick Facts - **Brand:** Heltec Automation - **Board Type:** dev-board - **Price:** ~$4.9 - **Product Readiness:** developer - **CPU:** RISC-V 32-bit single-core @ 160MHz, hardware crypto (AES/SHA/RSA/ECC) - **CPU Architecture:** RISC-V - **CPU Cores:** 1 - **RAM:** 400KB SRAM - **Flash:** 4MB (SiP) - **USB:** USB-C (via CH340K) - **Power:** 5V via USB-C,3.7V LiPo battery - **Operating Voltage:** 3.3V - **Operating Temp:** -20°C to +70°C - **Dimensions:** 40.64 × 20.32 × 7.6mm - **Weight:** 15g - **Battery:** External 3.7V LiPo (SH1.25 connector) - **Antenna:** Built-in PCB antenna - **SD Card:** No ## Connectivity - **Wifi:** 802.11 b/g/n - **Bluetooth:** BLE 5.0 ## Open Source - **Firmware:** Yes - **Schematics:** Yes - **PCB Layout:** No ## Compatible Firmware arduino, esphome, tasmota, micropython ## Use Cases - iot - smart-home - home-automation - environmental-monitoring - wireless-sensor-node - battery-powered-sensor - data-logging - prototyping ## Components - **ESP32-C3FN4** (mcu): Espressif RISC-V 32-bit single-core MCU at 160MHz with integrated 4MB flash, 802.11 b/g/n WiFi, BLE 5.0, and hardware crypto acceleration (AES/SHA/RSA/ECC). — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.espressif.com%2Fsites%2Fdefault%2Ffiles%2Fdocumentation%2Fesp32-c3_datasheet_en.pdf&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) - **TP4054** (battery-charger): Standalone constant-current/constant-voltage linear charger for single-cell lithium-ion batteries with programmable charge current up to 800mA and automatic termination. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fmedia.digikey.com%2Fpdf%2FData%2520Sheets%2FUTD%2520Semi%2520PDFs%2FTP4054.pdf&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) - **CH340K** (usb-serial): USB to UART serial converter with integrated clock generator requiring no external crystal oscillator. Supports 5V, 3.3V, 2.5V, and 1.8V I/O with built-in diode protection. — [Datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fwww.wch-ic.com%2Fproducts%2FCH340.html&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) ## Protocols - **UART0** (UART0): TX: GPIO21, RX: GPIO20 - **UART1** (UART1): TX: GPIO7, RX: GPIO6 - **I2C**: SDA: GPIO1, SCL: GPIO0 - **SPI** (SPI2): SCK: GPIO4, MOSI: GPIO5, MISO: GPIO6, CS: GPIO7 - **PWM** - **USB-JTAG**: D+: GPIO19, D-: GPIO18 ## GPIO Map | Pin | Name | Type | Functions | |-----|------|------|-----------| | GPIO0 | I2C SCL / ADC1_CH0 | I2C | digital-input, digital-output, adc, pwm, rtc | | GPIO1 | I2C SDA / ADC1_CH1 | I2C | digital-input, digital-output, adc, pwm, rtc | | GPIO2 | ADC1_CH2 (Strapping) | | digital-input, digital-output, adc, pwm, strapping, rtc | | GPIO3 | ADC1_CH3 | | digital-input, digital-output, adc, pwm, rtc | | GPIO4 | SPI SCK / ADC1_CH4 | SPI | digital-input, digital-output, adc, pwm, rtc | | GPIO5 | SPI MOSI / ADC2_CH0 | SPI | digital-input, digital-output, adc, pwm, rtc | | GPIO6 | UART1 RX / SPI MISO | UART | digital-input, digital-output, pwm | | GPIO7 | UART1 TX / SPI CS | UART | digital-input, digital-output, pwm | | GPIO8 | General GPIO (Strapping) | | digital-input, digital-output, pwm, strapping | | GPIO9 | Boot Button (Strapping) | | digital-input, digital-output, pwm, strapping | | GPIO10 | General GPIO | | digital-input, digital-output, pwm | | GPIO18 | USB-JTAG D- | USB | digital-input, digital-output | | GPIO19 | USB-JTAG D+ | USB | digital-input, digital-output | | GPIO20 | UART0 RX | UART | digital-input, digital-output, pwm | | GPIO21 | UART0 TX | UART | digital-input, digital-output, pwm | ## Description ## Overview The Heltec ESP32-C3 Arduino Development Board is a compact, low-power IoT development platform built around the Espressif ESP32-C3FN4 system-on-chip. Featuring a 32-bit RISC-V single-core processor clocked at up to 160 MHz, 4 MB of integrated flash, and dual-mode 2.4 GHz WiFi plus Bluetooth LE 5.0 connectivity, it provides a capable foundation for wireless sensor nodes, home automation endpoints, and battery-powered IoT devices. The board stands out for its integrated lithium battery management with charge/discharge control and overcharge protection, making it immediately suitable for portable and battery-powered applications without requiring external power management circuitry. A USB Type-C port with CH340K serial converter handles both programming and charging, while the ultra-low deep sleep current of 3.5 microamps enables long-term battery-operated deployments. Measuring just 40.64 x 20.32 mm and weighing only 15 grams, the board exposes 2x11 pin headers providing access to GPIO pins with ADC, SPI, I2C, UART, and PWM capabilities. It is compatible with Arduino, ESPHome, Tasmota, MicroPython, and other ESP32-C3 firmware platforms, giving developers wide flexibility in choosing their development environment. The board is well-suited for smart home sensors, environmental monitoring stations, wireless data loggers, and educational electronics projects. ## Where to Buy - [Heltec Official Store](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fesp32-c3%2F&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) — $4.90 ## Resources - [product](https://openhardware.directory/r?to=https%3A%2F%2Fheltec.org%2Fproject%2Fesp32-c3%2F&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) - [github](https://openhardware.directory/r?to=https%3A%2F%2Fgithub.com%2FHelTecAutomation%2FHeltec_ESP32&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) - [wiki](https://openhardware.directory/r?to=https%3A%2F%2Fwiki.heltec.org%2F&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) - [datasheet](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FESP32-C3_DevBoard%2FESP32-C3_DevBoard%28Rev1.1%29.pdf&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) - [schematics](https://openhardware.directory/r?to=https%3A%2F%2Fresource.heltec.cn%2Fdownload%2FESP32-C3_DevBoard%2FESP32-C3_DevBoard_Schematic_Diagram.pdf&ref=openhardware.directory&product=heltec-esp32-c3&source=md-export) ## Tags `esp32-c3`, `risc-v`, `wifi`, `ble`, `battery`, `iot`, `heltec`, `arduino`, `low-power`, `usb-c` ## Images ![Heltec ESP32-C3 Arduino Development Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-esp32-c3/f4d4df579113.png) ![Heltec ESP32-C3 Arduino Development Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-esp32-c3/fa12b5670b01.png) ![Heltec ESP32-C3 Arduino Development Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-esp32-c3/ab8eda8d458d.png) ![Heltec ESP32-C3 Arduino Development Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-esp32-c3/cd0b2f91ea0d.png) ![Heltec ESP32-C3 Arduino Development Board](https://nbg1.your-objectstorage.com/openhardware-directory/entities/heltec-esp32-c3/b522ca51c7d0.png) > **Battery Powered:** true --- [View full device page](https://openhardware.directory/devices/heltec-esp32-c3)