This week, I am feeling very excited! I am working with output devices, and I love seeing them come to life. It is always fun when something I built actually works

At the same time, I have decided to design a XIAO ESP32-C3 board to make interfacing with output devices easier. I started by planning the connections and choosing the right pins. Then, I worked on coding and testing. Some things did not work at first, but I kept fixing the errors and learning from them.

Now, I can control different devices smoothly, and it feels great! I enjoy both the challenges and the successes in this process. This week has been an important step in my project, and I am looking forward to doing more.

Designing XIAO ESP32C3 in KICAD 9.0

Last week, I finished designing the schematic diagram for the XIAO ESP32-C3. After that, I worked on the PCB layout and made sure all the rules were checked, like electrical connections and design guidelines. Everything looks good, and the layout is ready for the next steps

After successfully verifying the Design Rule Check (DRC) and Electrical Rules Check (ERC), importing the schematic into the PCB editor was the next logical step. Laying out all the routing traces ensures proper connectivity while optimizing for signal integrity and efficient space usage on the board.

Setting the trace width to 0.8mm ensures better current handling and maintains signal integrity across the board. Select the lines and press the "E" from keyboard to adjust the trace width.

After completing the routing and validation checks, using the Fabrication Output option from the File menu allowed you to generate the Gerber files for manufacturing. By choosing the SVG format, you ensured clear and precise visualization of the F.Cu (Front Copper) layer and the Edge Cut separately.

After exported the SVG image, uploaded to Mods Project Website for generating the nc file

After uploading SVG, I have processed step by step to generate the code for Fcu and Edgecut layers

Cliked the view option in mill raster 2d , it will open the f-cu layer file and downloaded as .nc

Again the same process will be used for generating the edge cut file without using Vbit tool. Both the views are attached below

After completing the milling and soldering process, my PCB finally took shape! The precise cuts from milling ensured clean edges, while soldering each component brought the design to life. As I inspected the board, I felt a sense of achievement—every trace, every connection was carefully placed to make sure everything functioned as expected.

The moment of truth arrived when I powered it up. Watching the board respond just as I had planned was incredibly satisfying.

Output Devices

This week, I was really excited to work with output devices using the XIAO ESP32-C3! I m used to connect a servo motor, a 1.3-inch OLED display, and an RGB LED, and waiting to program the same to see the repsonses.Each step—from wiring the connections to debugging—felt like a great learning experience. I'm looking forward to exploring even more possibilities with these output devices!

PIN LAYOUT OF XIAO ESP32C3 for my reference

Servo motor Interfacing

The servo motor has a fascinating history, starting from early attempts at precise control mechanisms in the 19th century to becoming an essential component in robotics and automation today.Thats why today i m trying today

Connections:

Servo Signal Pin → Connect to D5 (XIAO ESP32C3)

Servo Power (VCC) → Connect to 5V (XIAO ESP32C3).

Servo Ground (GND) → Connect to ESP32-C3 GND.

For prgoramming Arduino IDE is used to program the XIAO ESP32C3. Servo motor interfacing program is given below

#include 

Servo myServo;
#define SERVO_PIN 6 // Adjust based on your setup

void setup() {
  myServo.attach(SERVO_PIN);
  Serial.begin(115200);
}

void loop() {
  for (int angle = 0; angle <= 180; angle += 10) {
    myServo.write(angle);
    Serial.print("Servo Angle: ");
    Serial.println(angle);
    delay(500);
  }
  
  for (int angle = 180; angle >= 0; angle -= 10) {
    myServo.write(angle);
    Serial.print("Servo Angle: ");
    Serial.println(angle);
    delay(500);
  }
}

RGB Led Interfacing

Arduino sketch for controlling an RGB LED with the Xiao ESP32-C3. I have connected the LED connections align with the Xiao ESP32-C3’s GPIO mapping, and adjust the pins if needed. Since the ESP32-C3 uses PWM channels differently than traditional Arduino boards, you may need to use instead of for smoother color transitions

The program uses PWM to control the brightness of each color (Red, Green, and Blue).

Connections: R (Red) → D10 , G (Green) → D9, B (Blue) → D6 and GND (RGB LED) to GND (XIAO)

GND → GND

These should be connected to PWM-compatible pins on the ESP32-C3 and Program used to upload in Esp

// Define RGB LED pins
#define RED_PIN 10
#define GREEN_PIN 9
#define BLUE_PIN 6

void setup() {
    // Set RGB pins as outputs
    pinMode(RED_PIN, OUTPUT);
    pinMode(GREEN_PIN, OUTPUT);
    pinMode(BLUE_PIN, OUTPUT);
}

void loop() {
    setColor(255, 0, 0); // Red
    delay(1000);
    setColor(0, 255, 0); // Green
    delay(1000);
    setColor(0, 0, 255); // Blue
    delay(1000);
    setColor(255, 255, 0); // Yellow
    delay(1000);
    setColor(0, 255, 255); // Cyan
    delay(1000);
    setColor(255, 0, 255); // Magenta
    delay(1000);
    setColor(255, 255, 255); // White
    delay(1000);
    setColor(0, 0, 0); // Off
    delay(1000);
}

void setColor(int red, int green, int blue) {
    analogWrite(RED_PIN, red);
    analogWrite(GREEN_PIN, green);
    analogWrite(BLUE_PIN, blue);
}

1.3" OLED Interfacing

Interfacing a 1.3" OLED display with the XIAO ESP32-C3 using the I2C protocol is quite straightforward. Below are the connections, library setup, and example code to display text on the OLED.

Connection pins

OLED <-----> XIAO ESP

VCC → Connect to 3.3V (or 5V, depending on the OLED module).

GND → Connect to GND.

SCL → Connect to D5

SDA → Connect to D4

After given the connections, program taken from chatgpt uploaded to xiao esp32, My display not turned on

Prompt the error in chatgpt , i got to know that, Install Required LibrariesManage Libraries. Adafruit GFX Library and Adafruit SSD1306 Library

Still i got the error and based on youtube reference Youtube video and i have watched the video and installed the library U8g2lib.h

Again i referred the following website from the youtube link given , Github link , My OLED is turned on

Uploaded the following code

#include 
#include 

// Define I2C pins
#define SDA 4  
#define SCL 5  

// Initialize the 128x64 OLED display
U8G2_SSD1306_128X64_NONAME_F_HW_I2C DISPB(U8G2_R0, /* reset=*/ U8X8_PIN_NONE);

void setup() {
    // Set I2C pins as outputs
    pinMode(SDA, OUTPUT);  
    pinMode(SCL, OUTPUT);

    // Set I2C bus speed
    Wire.setClock(100000);
    DISPB.setBusClock(100000);

    // Set OLED display address (adjust if needed)
    DISPB.setI2CAddress(0x78);

    // Initialize the display
    DISPB.begin();

    // Set font
    DISPB.setFont(u8g2_font_logisoso16_tf);
}

void loop() {
    // Clear the display buffer
    DISPB.clearBuffer();

    // Set cursor position and print text
    DISPB.setCursor(0, 31);
    DISPB.print("FAB ACADEMY");
    DISPB.setCursor(40, 63);
    DISPB.print("sujith");

    // Send the buffer content to the display
    DISPB.sendBuffer();
}