The ESP32-C3 is the latest development from seeed studio. It is extremely small (2.2x1.8 mm), has WiFi and Bluetooth BLE on board, a connector for an external antenna, 4 analogue and 10 digital pins, as well as connectors for I2C, UART and SPI. The chip has 400 KB SRAM and 4 MB flash.

The ESP32-C3 needs very little energy (~44 μA) in deep sleep and a built-in IC even supports battery charging.

For further product details, please visit the seeed studio website.

Handling it is sometimes a bit tricky, maybe this tutorial will help you.

Supplies

Sources of supply:

seeed studio ($ 4.99)

pimoroni.com ( £ 6.00)

USB Type C cable, Arduino IDE

ESP32-C3 XIAO

Step 1: First Steps: Software Setups

It is required that you have downloaded and installed the Arduino IDE.

start the Arduino IDE
got to File > Preferences, and klick at the windows symbol behind "Additional Boards Manager URLs", a window will appear, insert this url there:
https://raw.githubusercontent.com/espressif/arduino-esp32/gh-pages/package_esp32_dev_index.json

got to Tools > Board > Boards Manager, type "esp32" into the search box, select the latest version of "esp32" and press "install".

Step 2: Select Board and Port

Select your board:

go to Tools > Board > ESP32 Arduino and select "XIAO_ESP32C3". (This entry is quite at the end of this long list).

Select your port:

plugin your ESP32-C3 to a free USB port of your computer
go to Tools > Port and select the serial port name of your connected ESP32-C3. Usually it is NOT COM1 or COM2, it's a higher number.

Step 3: Software Tipps

Please use Arduino software developed for ESP32, not for Arduino UNO or ESP8266. This is especially important for some libraries.

(If you want to use Wifi and/or BLE, you have to carefully plug in the antenna first.)

For a start, you can make an LED blink:

File > Examples > Basics > Blink For this sketch you need an LED and a resistor and you should insert "#define LED_BUILTIN 2" before "void setup();

If you want to use the pins as inputs or outputs, you have to specify the GPIO numbers, not the a(nalog) or d(igital) numbers!

Step 4: Upload

This part can be a bit tricky and frustrating. (Here I spent a lot of time trying things out).

disconnect the ESP32-C3 from USB
press the boot button on your ESP32-C3 and hold it.
plug in the USB
press the upload button in Arduino IDE
wait a few seconds
than release the boot button

(Sometimes it is also useful to change upload speed from 921600 to 512000 baud.)
Compared to an Arduino nano, the upload takes quite a long time anyway!