Circuit Documentation

Summary

This circuit is built around an ATMEGA328 microcontroller and includes various components such as resistors, capacitors, LEDs, a crystal oscillator, a pushbutton, a 5V battery, and an FTDI programmer. The circuit is designed to blink an LED connected to pin D13 of the ATMEGA328 microcontroller.

Component List

1. ATMEGA328 Microcontroller

   • Pins: RESET, D0, D1, D2, D3, D4, VCC, GND, CRYSTAL, D5, D6, D7, D8, D9, D10, D11, D12, D13, AREF, A0, A1, A2, A3, A4, A5
   • Description: Main microcontroller used for processing and control.

2. 5V Battery

   • Pins: +, -
   • Description: Power supply for the circuit.

3. Resistor (10k Ohms)

   • Pins: pin1, pin2
   • Description: Used for pull-up or current limiting purposes.
   • Properties: Resistance: 10k Ohms

4. Resistor (200 Ohms)

   • Pins: pin1, pin2
   • Description: Used for current limiting.
   • Properties: Resistance: 200 Ohms

5. Ceramic Capacitor (0.1 µF)

   • Pins: pin0, pin1
   • Description: Used for decoupling and filtering.
   • Properties: Capacitance: 0.1 µF

6. Ceramic Capacitor (22 pF)

   • Pins: pin0, pin1
   • Description: Used for crystal oscillator stabilization.
   • Properties: Capacitance: 22 pF

7. Crystal Oscillator

   • Pins: pin 0, pin 1
   • Description: Provides clock signal for the microcontroller.

8. LED: Two Pin (red)

   • Pins: cathode, anode
   • Description: Indicator LED.

9. FTDI Programmer

   • Pins: DTR, RX, TX, VCC, CTS, GND
   • Description: Used for programming the microcontroller.

10. Pushbutton

    • Pins: Pin 3 (out), Pin 4 (out), Pin 1 (in), Pin 2 (in)
    • Description: Used for user input.

Wiring Details

ATMEGA328 Microcontroller

• VCC is connected to:

  • Resistor (10k Ohms) pin1
  • Ceramic Capacitor (0.1 µF) pin0
  • 5V Battery +
  • FTDI Programmer VCC

• GND is connected to:

  • Pushbutton Pin 2 (in)
  • Ceramic Capacitor (0.1 µF) pin1
  • 5V Battery -
  • FTDI Programmer GND
  • LED (red) cathode

• RESET is connected to:

  • Resistor (10k Ohms) pin2
  • Pushbutton Pin 4 (out)
  • Ceramic Capacitor (0.1 µF) pin0

• D0 is connected to FTDI Programmer TX

• D1 is connected to FTDI Programmer RX

• D13 is connected to Resistor (200 Ohms) pin1

• CRYSTAL is connected to:

  • Crystal Oscillator pin 0
  • Crystal Oscillator pin 1
  • Ceramic Capacitor (22 pF) pin0
  • Ceramic Capacitor (22 pF) pin1

• AREF is connected to 5V Battery +

5V Battery

• + is connected to:

  • ATMEGA328 VCC
  • FTDI Programmer VCC
  • Resistor (10k Ohms) pin1
  • Ceramic Capacitor (0.1 µF) pin0

• - is connected to:

  • ATMEGA328 GND
  • FTDI Programmer GND
  • Pushbutton Pin 2 (in)
  • Ceramic Capacitor (0.1 µF) pin1
  • LED (red) cathode

Resistor (10k Ohms)

• pin1 is connected to:

  • ATMEGA328 VCC
  • 5V Battery +
  • Ceramic Capacitor (0.1 µF) pin0

• pin2 is connected to:

  • ATMEGA328 RESET
  • Pushbutton Pin 4 (out)
  • Ceramic Capacitor (0.1 µF) pin0

Resistor (200 Ohms)

• pin1 is connected to ATMEGA328 D13

• pin2 is connected to LED (red) anode

Ceramic Capacitor (0.1 µF)

• pin0 is connected to:

  • ATMEGA328 VCC
  • Resistor (10k Ohms) pin1
  • 5V Battery +

• pin1 is connected to:

  • ATMEGA328 GND
  • 5V Battery -

Ceramic Capacitor (22 pF)

• pin0 is connected to:

  • Crystal Oscillator pin 0
  • ATMEGA328 CRYSTAL

• pin1 is connected to:

  • Crystal Oscillator pin 1
  • ATMEGA328 CRYSTAL

Crystal Oscillator

• pin 0 is connected to:

  • Ceramic Capacitor (22 pF) pin0
  • ATMEGA328 CRYSTAL

• pin 1 is connected to:

  • Ceramic Capacitor (22 pF) pin1
  • ATMEGA328 CRYSTAL

LED: Two Pin (red)

• cathode is connected to:

  • ATMEGA328 GND
  • 5V Battery -
  • FTDI Programmer GND

• anode is connected to:

  • Resistor (200 Ohms) pin2

FTDI Programmer

• VCC is connected to:

  • ATMEGA328 VCC
  • 5V Battery +

• GND is connected to:

  • ATMEGA328 GND
  • 5V Battery -
  • LED (red) cathode

• DTR is connected to Ceramic Capacitor (0.1 µF) pin1

• RX is connected to ATMEGA328 D1

• TX is connected to ATMEGA328 D0

Pushbutton

• Pin 2 (in) is connected to:

  • ATMEGA328 GND
  • 5V Battery -

• Pin 4 (out) is connected to:

  • Resistor (10k Ohms) pin2
  • ATMEGA328 RESET
  • Ceramic Capacitor (0.1 µF) pin0

Code Documentation

ATMEGA328 Microcontroller Code

int LEDpin = D13;
int delayT = 1000;

void setup() {
  // put your setup code here, to run once:
  pinMode(LEDpin, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(LEDpin, HIGH);
  delay(delayT);
  digitalWrite(LEDpin, LOW);
  delay(delayT);
}

Description:

• LEDpin: Defines the pin connected to the LED.
• delayT: Defines the delay time in milliseconds.
• setup(): Configures the LED pin as an output.
• loop(): Turns the LED on and off with a delay, creating a blinking effect.