KAmod ESP32 C3

Description

KAmod ESP32-C3 - Development board with ESP32-C3 Mini-1 module
The KAmod ESP32-C3 board features the ESP32-C3 Mini-1 module from Espressif, which contains a 32-bit, single-core SoC microcontroller based on the RISC-V architecture. It includes Wi-Fi and Bluetooth 5 (LE) radio interfaces with Long Range (LR) mode support.

The MCU operates at a maximum clock frequency of 160 MHz and is equipped with 400 kB of RAM and 4 MB of Flash memory. It supports low power consumption modes, operates in temperatures from -40 to +85°C, and implements security features such as Secure Boot and Flash encryption with AES-128/256-XTS. These extensive specifications make it ideal for industrial and IoT applications. Additionally, the board includes a high-precision SHTC3 temperature and humidity sensor, an ICM42670 MEMS sensor (3-axis gyroscope and 3-axis accelerometer), a WS2812 RGB LED, and a standard LED connected to one of the microcontroller ports. These components facilitate the rapid building of diverse applications.

The module is powered by +5V via a USB-C connector or by a Li-Ion battery. The +3.3 V voltage for the microcontroller and peripherals is generated by a SY8088 Buck DC/DC converter (input range 2.5–5 V). If USB-C power is disconnected, power is automatically drawn from the battery (if connected). The power system includes an MCP7381 Li-Ion battery charger powered via USB-C.

The KAmod ESP32-C3 module is designed for developing and testing applications in the Arduino environment (C/C++) as well as in Rust.

Key Features and Parameters

ESP32C3 Mini-1 Module (Wi-Fi 802.11 b/g/n, Bluetooth 5 LE)
32-bit RISC-V single-core MCU @ 160 MHz, 400 kB SRAM, 4 MB Flash
15 GPIO lines
Communication interfaces: SPI, I2C, I2S, UART, USB
12-bit SAR ADC (up to 6 channels)
ICM42670 Accelerometer/Gyroscope
- 3-axis MEMS gyroscope (X, Y, Z angular rate)
- 3-axis MEMS accelerometer (X, Y, Z axis)
- Communication interface: I2C
SHTC3 Thermometer/Hygrometer
- Humidity range: 0…100%RH (+/- 2% accuracy)
- Temperature range: -40 to +125 °C (+/-0.2°C accuracy from 0°C to +60°C)
- Communication interface: I2C
SY8088 DC/DC Converter
MCP73831 Li-Ion Battery Charger
Programmable WS2812 RGB LED
USB-C Connector
- +5V Power supply
- Flash programming interface
- JTAG interface
Reset and Boot buttons

Standard Equipment

Code	Description
KAmod ESP32-C3	Assembled and tested module 1 x straight 12-pin goldpin header (2.54 mm pitch) 1 x straight 16-pin goldpin header (2.54 mm pitch)

Electrical Schematic

Pinout Description

Power Supply

The module is powered by VBUS (+5 V) from the USB-C connector. This voltage also charges the 4.2 V Li-Ion battery if connected to the Charger output. The MCP7381 chip manages the charging process using a Constant Current/Constant Voltage (CC/CV) algorithm, with the charging current set to 100 mA and the termination voltage to 4.20 V.

Arduino IDE Configuration and Test Program

Preliminary Steps

Connect the KAmod ESP-C3 module to a computer with Arduino IDE installed. In the board selection menu, choose ESP32C3 Dev Module and the corresponding virtual COMx port.

For the test procedure, we will use the Serial Monitor to display results. To enable this, you must unlock the USB CDC On Boot option (disabled by default).

Preferences Configuration

Open File -> Preferences. In the Additional boards manager URLs field, enter: https://dl.espressif.com/dl/package_esp32_index.json

Selecting the Processor Type

Navigate to Tools -> Board -> esp32 -> ESP32C3 Dev Module. This step ensures the project compiles for the correct architecture.

Installing Libraries

The test program requires libraries for the ICM42670P accelerometer, SHTC3 thermometer/hygrometer, and WS2812B RGB LED.

ICM42670P Library

Search for "ICM42670" in the Library Manager, select ICM42670P by TDK/Invensense and click Install.

SHTC3 Library

Search for Adafruit SHTC3 Library. When prompted, click Install All to include necessary dependencies.

WS2812 RGB LED Library

Install the Adafruit NeoPixel library.

Handling the ICM42670P Accelerometer

The sensor uses the I2C bus. We initialize the interface using the Wire library:

define I2C_SDA 10 // SDA on IO10
define I2C_SCL 8 // SCL on IO8

Wire.begin(I2C_SDA, I2C_SCL);

Handling the SHTC3 Sensor

Initialized via the standard begin method:

shtc3.begin();
Reading data:

shtc3.getEvent(&humidity, &temp); // read temp and humidity
Results are stored in `temp.temperature` and `humidity.relative_humidity`.

Handling the WS2812B RGB LED

Define the number of pixels and the data pin:

define PIN_WS2812B 2 // Data pin
define NUM_PIXELS 1 // One LED

Adafruit_NeoPixel WS2812B(NUM_PIXELS, PIN_WS2812B, NEO_GRB + NEO_KHZ800);

Wi-Fi Module Testing

The test scans local networks and displays the SSID, signal strength (RSSI), channel, and encryption type in the console.

WiFi.mode(WIFI_STA); // Station mode
WiFi.disconnect(); // Clear previous connections
numNetworks = WiFi.scanNetworks();

Arduino Test Program Code

The full test program blinks the LED, reads IMU and SHTC3 data, scans Wi-Fi, and cycles the RGB LED colors.

#include "WiFi.h"
#include <Wire.h>
#include <Adafruit_NeoPixel.h>
#include "Adafruit_SHTC3.h"
#include "ICM42670P.h"

#define LED_BUILTIN 7
#define I2C_SDA 10
#define I2C_SCL 8
#define PIN_WS2812B 2
#define NUM_PIXELS 1

Adafruit_NeoPixel WS2812B(NUM_PIXELS, PIN_WS2812B, NEO_GRB + NEO_KHZ800);
ICM42670 IMU(Wire,0);
Adafruit_SHTC3 shtc3 = Adafruit_SHTC3();

void setup() {
    WS2812B.begin();
    WS2812B.setBrightness(50);
    pinMode(LED_BUILTIN, OUTPUT);
    Serial.begin(115200);
    delay(2000);
    while(!Serial);
    Wire.begin(I2C_SDA, I2C_SCL);
    IMU.begin();
    IMU.startAccel(100, 16);
    IMU.startGyro(100, 2000);
    shtc3.begin();
    WiFi.mode(WIFI_STA);
    WiFi.disconnect();
    delay(100);
}

void loop() {
    int numNetworks;
    sensors_event_t humidity, temp;
    inv_imu_sensor_event_t imu_event;
    digitalWrite(LED_BUILTIN, HIGH);
    
    Serial.println("\n********************************");
    if (IMU.getDataFromRegisters(imu_event) == 0) {
        Serial.print("Accel X: "); Serial.println(imu_event.accel[0] / 2048.0);
        Serial.print("Gyro X: "); Serial.println(imu_event.gyro[0] / 16.4);
    }
    
    shtc3.getEvent(&humidity, &temp);
    Serial.print("SHTC3 Temp: "); Serial.println(temp.temperature);
    
    numNetworks = WiFi.scanNetworks();
    Serial.print(numNetworks); Serial.println(" networks found.");
    
    digitalWrite(LED_BUILTIN, LOW);
    WS2812B.setPixelColor(0, WS2812B.Color(255, 0, 0)); WS2812B.show(); delay(500);
    WS2812B.setPixelColor(0, WS2812B.Color(0, 255, 0)); WS2812B.show(); delay(500);
    WS2812B.setPixelColor(0, WS2812B.Color(0, 0, 255)); WS2812B.show(); delay(500);
    WS2812B.clear(); WS2812B.show();
}

Rust Programming Setup and Test Programs

This section describes how to configure the environment on Linux Ubuntu (24.04.2 LTS) to develop for ESP32-C3 in Rust.

Step 1: Install Prerequisites

Install essential libraries, Clang compiler, and Python tools:

Step 2: Install Rust and Cargo Tools

Install Cargo modules for ESP development:

`espflash` for flashing memory
`ldproxy` for linker arguments
`cargo-generate` for project templates

Step 3: Creating a Project

Run `cargo generate esp-rs/esp-idf-template cargo`. Select MCU `ESP32C3` and ESP-IDF version `v5.3`.

To compile and run: `cargo run`.

Rust Example: Blinking LED

use esp_idf_svc::hal::{delay::FreeRtos, gpio::PinDriver, peripherals::Peripherals};

fn main() {
    esp_idf_svc::sys::link_patches();
    let peripherals = Peripherals::take().expect("Failed to take peripherals");
    let mut led = PinDriver::output(peripherals.pins.gpio7).expect("Failed to create led driver");
    loop {
        led.toggle().expect("Failed to toggle LED");
        FreeRtos::delay_ms(500);
    }
}

Rust Example: SHTC3 and ICM42670 Data

After running `cargo run`, the terminal will display sensor data every second.

Dimensions

The KAmod ESP32-C3 board dimensions are 63 x 27 mm.