Week 4 Embedded Programming

Group Assignment

Test and compare different development software and programming languages, like Arduino, Micropython,ESP-IDF,or more

Individual Assignment

Choose an MCU board as the hardware programming platform

check the datasheet of the chip used in the MCU and record, architechture,Memory,Peripherals(ADC,etc),supported programming software,or more

Use simulation software to program the selected board. Create three programs:

2.1 Basic operation (e.g., turn on the LED on the board)

2.2 Connect an input or output device and successfully read/display data

2.3 Use the communication methods supported by the board (Wired: UART, I2C, SPI;Wireless: Wi-Fi, Bluetooth)

Individual Assignment

XIAO ESP32-C3

Seeed Studio XIAO ESP32-C3 adopts new RISC-V architecture, supporting both Wi-Fi and BLE wireless connectivities, widely used for IoT project.

Color	Label	Functional Description
Pink	Touch	Capacitive Touch pins. These can detect electrical charges from a human finger, allowing you to create touch-sensitive buttons without mechanical parts.
Green	Digital	Digital Input/Output (I/O) pins. These pins handle binary signals: either High (3.3V) or Low (0V).
Orange	Analog	Analog-to-Digital Converter (ADC) pins. These can measure varying voltage levels (e.g., from a potentiometer or light sensor) and convert them into digital values.
Grey	GPIO	General Purpose Input/Output. This is the standard label for pins that can be programmed to perform various input or output tasks.
Dark Grey	IIC (I2C)	Stands for Inter-Integrated Circuit. A communication protocol using two wires (SDA for data and SCL for clock) to connect sensors, OLED screens, and other modules.
Red	Power	Power pins. Includes 5V (USB power/External input) and 3V3 (regulated 3.3V output for the chip and low-power peripherals).
Black	GND	Ground. The common reference point (0V) for the entire electrical circuit. Always connect your oscilloscope ground clip here.
Yellow	SPI	Serial Peripheral Interface. A high-speed synchronous data bus used for fast communication with devices like SD card modules or LCD displays.
Blue	UART	Universal Asynchronous Receiver/Transmitter. Used for serial communication (TX/RX), typically for debugging or communicating with a computer or GPS modules.

Feature of the SOC

ESP32-C3 is a low-power and highly-integrated MCU-based solution that supports 2.4 GHz Wi-Fi and Bluetooth® Low Energy (Bluetooth LE). The functional block diagram of the SoC is shown below.

Programming software

Arduino IDE

MicroPython / CircuitPython

VS Code + PlatformIO

ESP-IDF

XIAO RP2040

XIAO RP2040 is a compact, Arduino-compatible dev board based on Raspberry Pi RP2040，a cost-effective and user-friendly microcontroller for learning coding. (without Wireless connectivity)

Feature of the SoC

Programming software

Arduino IDE

Python

VS Code + PlatformIO

Microsoft MakeCode

C/C++ SDK (CMake)

Seeed Xiao ESP32 C3 VS Seeed Xiao RP2040 - Main difference

Description	Xiao ESP 32-C3	Xiao RP2040
Architecture	RISC-V	Dual-core ARM Cortex-M0+
Processor	ESP 32 -C3	Rasperry pi 2040
Wireless connectivity	Wifi,BLE	no
Power	Support 3.7 v Li-ion(battery)	no
Application	Iot project for scaling up	IoT prototying/Learning

Coding Environment

Xiao ESP 32 C3 with Arduino IDE

Xiao ESP 32 C3 with Microphython

Xiao ESP 32 C3 with CircuitPython

Running on simulation software (https://wokwi.com/)

Turn on the LED

Step 1 open the website and select Xiao ESP32-S3

Step 2 select the module, LED and resistor, a resistor is required for the circuit.

Step 3 connect them to a circuit

Step 4 turn on the LED, 1s on and 1s off and loop

The Code was generated by Gemini

// Basic LED blink on XIAO ESP32C3
void setup() {
  // Configure D5 as output pin
  pinMode(D5, OUTPUT);
}

void loop() {
  // LED ON for 1 second
  digitalWrite(D5, HIGH);
  delay(1000);

  // LED OFF for 1 second
  digitalWrite(D5, LOW);
  delay(1000);
}

“Hello World”

When connected with power, it will show “ hello Word” for 1 second, and stop 1 second, and the repeated.

Step 1 select the 2 module, Xiao -ESP 32 -S3 and LCD 16x2 (I2C)

Pin of LCD 16x2 (I2C)

Pin Name	Full Name	Description	Connection (XIAO S3)
GND	Ground	The common reference point for the electrical circuit (Negative pole). It must be connected to complete the circuit.	GND
VCC	Voltage Collector Common	The power supply input for the LCD and the I2C adapter. Most LCDs require 5V for optimal contrast.	5V / VIN
SDA	Serial Data	The bidirectional line used to transmit data bits between the ESP32-S3 and the LCD display.	D4 (GPIO 5)
SCL	Serial Clock	The signal line that carries the clock pulses to synchronize the data transfer on the SDA line.	D5 (GPIO 6)

Step 2 connect with cable as below

Step 3 code as below

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Make sure I2C address matches your module/JSON config
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  // Start I2C with XIAO S3 pin mapping: SDA=D4(GPIO5), SCL=D5(GPIO6)
  Wire.begin(5, 6);

  // Initialize LCD and turn on backlight
  lcd.init();
  lcd.backlight();

  // Show startup message once
  lcd.setCursor(0, 0);
  lcd.print("System Ready");
}

void loop() {
  // Display text with backlight on
  lcd.backlight();
  lcd.setCursor(0, 0);
  lcd.print("Hello world "); // trailing space clears leftover characters
  delay(1000);

  // Turn off backlight for 1 second
  lcd.noBacklight();

  // Avoid frequent clear() in loop to reduce flicker
  delay(1000);
}

Finally, it works as below,

Light up the LED in the physical world

Step 1 download the Arduino IDE, add ESP32 board package to your Arduino IDE

Navigate to File > Preferences, and fill "Additional Boards Manager URLs" with the url below: https://jihulab.com/esp-mirror/espressif/arduino-esp32.git

Install the ESP32 board package

Step2 Make a circuit as below, with Xiao ESP32 C3, cable, and LED, bread board.

Step 3 Copy the Code as above and run the program to light up the LED as in the video.

Video