What is it?

The ACH-ESP32-C3F4 is a thumb-sized, ultra-low-power IoT development board powered by the Espressif ESP32-C3FH4 open-standard 32-bit RISC-V microcontroller @ 160 MHz. Designed and hand-assembled in Vila Nova de Gaia / Porto, Portugal, it offers a modern alternative to traditional microcontrollers with robust Wi-Fi 4, Bluetooth 5.0 LE, and built-in hardware cryptographic security.

Despite its compact footprint, it features 4 MB of embedded Flash, an oversized 1000 mA (1A) low-noise LDO regulator, an addressable WS2812 RGB LED, and Achiraware's signature AchiWire I2C connector.

What makes it special?

• Modern 32-bit RISC-V Core: Built on the open-source RISC-V architecture @ 160 MHz with 400 KB SRAM.
• Solderless AchiWire I2C Port (JST SH 1.0mm 4-Pin): 100% plug-and-play compatible with SparkFun Qwiic and Adafruit STEMMA QT sensor breakout boards. Features built-in 4.7kΩ pull-up resistors on SDA (IO 6) and SCL (IO 7).
• Industrial 1A LDO Regulator: Uses the high-efficiency Texas Instruments TLV75733 low-dropout regulator, capable of outputting 1000 mA on the 3.3V rail. It easily powers power-hungry Wi-Fi bursts alongside external sensors and displays without brownouts.
• Tuned Planar Inverted-F PCB Antenna: Engineered for high sensitivity and stable Wi-Fi 4 and BLE 5 transmission even inside tight enclosures.
• Onboard WS2812 Smart RGB LED: Addressable status LED connected to GPIO 4 (silkscreen STATUS) for multi-color status alerts and indicators.
• Castellated Pads & Breadboard Spacing: 18 total pins (9 per side, 2.54mm pitch) with castellated edge pads. Perfect for breadboard prototyping or for reflow soldering directly as an SMD daughterboard module.
• Engineered in Porto, Portugal: Built with top-grade passives and tested individually in Portugal 🇵🇹 for fast, customs-free European delivery.

Technical Specifications

• Microcontroller: Espressif ESP32-C3FH4 (32-bit Single-Core RISC-V @ 160 MHz)
• Memory: 4 MB Embedded Flash + 400 KB Internal SRAM
• Wireless: 2.4 GHz Wi-Fi 4 (802.11 b/g/n) + Bluetooth 5.0 LE (with Long Range support)
• Antenna: Tuned planar inverted-F PCB antenna with low VSWR
• Crystal Oscillator: Diodes Inc FW400WFMR1 40.000 MHz high-precision crystal
• USB Connector: 16-pin USB Type-C with ESD protection diodes (Native USB-CDC serial console)
• Power Input (VIN): 3.3V to 5.5V via VIN pin or 5V via USB-C
• Voltage Regulator: Texas Instruments TLV75733 (3.3V @ 1000 mA output, thermal shutdown)
• I2C Connector: 4-pin JST SH 1.0mm AchiWire port (Qwiic / STEMMA QT compatible)
  • Pin 1: GND | Pin 2: +3.3V | Pin 3: SDA (IO 6) | Pin 4: SCL (IO 7)
• Indicators: Green Power LED (3.3V rail) + Addressable WS2812 Smart RGB LED (IO 4)
• Buttons: Tactile Reset Button (CHIP_PU) + Boot Button (IO 9)
• Pin Form Factor: 18 pins (2.54 mm pitch + castellated SMD edge pads)

Ecosystem Compatibility

• Arduino IDE: Native support via the official Espressif ESP32 core (ESP32C3 Dev Module).
• MicroPython: Fully supported using official ESP32-C3 generic firmware builds.
• ESP-IDF: Complete native support for production-ready C/C++ embedded firmware.

What's included in the box?

• 1× ACH-ESP32-C3F4 Development Board (tested and pre-flashed)
• 2× 9-pin male headers (2.54mm pitch, loose)
• Packed in an ESD anti-static protective bag

Open Source Hardware & Documentation

Schematics, full pinout charts, 3D STEP models, and code examples are open source on GitHub: 👉 https://github.com/AchirawareElectronics/ACH-ESP32-C3F4

At AchiraWare Electronics, all our boards and hardware products are carefully tested, packed in anti-static ESD packaging, and dispatched directly from our studio in Porto, Portugal.

1. Shipping Destinations We ship to customers across Portugal, Spain, and throughout the European Union. If you are located outside the EU, please reach out to us at customerservice@achiraware.com before placing an order.

2. Processing & Dispatch Times In-stock items: Orders are processed and dispatched within 1 to 2 business days (Monday to Friday, excluding national holidays in Portugal). Once your package has been shipped, you will receive an email confirmation with your tracking number.

3. Estimated Delivery Times Portugal (Continental): 24 to 48 hours (via CTT / Express Courier). Spain & Iberian Peninsula: 2 to 4 business days. Rest of the European Union: 3 to 7 business days depending on destination country and local postal services.

4. Shipping Costs Shipping rates are calculated dynamically at checkout based on your destination country and the weight/dimensions of your order.

5. Customs & Import Duties (EU Orders) Since all orders are shipped from Portugal (EU Member State), there are no customs duties or import tariffs for orders delivered within the European Union Single Market.

6. Damaged or Lost Shipments If your order arrives damaged or appears to have been opened in transit, please take photographs of the outer packaging and contents and notify us within 48 hours at customerservice@achiraware.com so we can resolve it immediately.