Circuit Documentation

Summary

This circuit involves an Arduino UNO microcontroller interfacing with multiple pushbuttons, a SIM900A GSM module, and a 16x2 I2C LCD display. The pushbuttons are used as input devices, while the SIM900A module and the LCD display serve as output devices. The Arduino UNO is programmed to handle the inputs and outputs accordingly.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

Pushbutton

• Description: A simple pushbutton switch.
• Pins: Pin 3 (out), Pin 4 (out), Pin 1 (in), Pin 2 (in)

SIM900A

• Description: A GSM/GPRS module for communication.
• Pins: GND, DB9-3 (RXD), DB9-2 (TXD), 5V, 3VR, 5VR, 3VT, 5VT, VCC, Ring, RESTART, RESET, STATUS

16x2 I2C LCD

• Description: A 16x2 character LCD display with I2C interface.
• Pins: GND, VCC, SDA, SCL

Wiring Details

Arduino UNO

• GND: Connected to GND of SIM900A, GND of 16x2 I2C LCD, and Pin 1 (in) and Pin 2 (in) of all Pushbuttons.
• 5V: Connected to 5V of SIM900A and VCC of 16x2 I2C LCD.
• D4: Connected to Pin 3 (out) and Pin 4 (out) of one Pushbutton.
• D3: Connected to Pin 3 (out) and Pin 4 (out) of another Pushbutton.
• D2: Connected to Pin 3 (out) and Pin 4 (out) of another Pushbutton.
• A4: Connected to SDA of 16x2 I2C LCD.
• A5: Connected to SCL of 16x2 I2C LCD.
• D9: Connected to DB9-2 (TXD) of SIM900A.
• D8: Connected to DB9-3 (RXD) of SIM900A.

Pushbutton 1

• Pin 1 (in): Connected to GND.
• Pin 2 (in): Connected to GND.
• Pin 3 (out): Connected to D4 of Arduino UNO.
• Pin 4 (out): Connected to D4 of Arduino UNO.

Pushbutton 2

• Pin 1 (in): Connected to GND.
• Pin 2 (in): Connected to GND.
• Pin 3 (out): Connected to D3 of Arduino UNO.
• Pin 4 (out): Connected to D3 of Arduino UNO.

Pushbutton 3

• Pin 1 (in): Connected to GND.
• Pin 2 (in): Connected to GND.
• Pin 3 (out): Connected to D2 of Arduino UNO.
• Pin 4 (out): Connected to D2 of Arduino UNO.

SIM900A

• GND: Connected to GND of Arduino UNO.
• 5V: Connected to 5V of Arduino UNO.
• DB9-2 (TXD): Connected to D9 of Arduino UNO.
• DB9-3 (RXD): Connected to D8 of Arduino UNO.

16x2 I2C LCD

• GND: Connected to GND of Arduino UNO.
• VCC: Connected to 5V of Arduino UNO.
• SDA: Connected to A4 of Arduino UNO.
• SCL: Connected to A5 of Arduino UNO.

Code Documentation

Arduino UNO Code

void setup() {
  // put your setup code here, to run once:

}

void loop() {
  // put your main code here, to run repeatedly:

}

This code is a basic template for the Arduino UNO. The setup() function is where you initialize your settings, and the loop() function is where the main code runs repeatedly. You can add your specific logic to handle the pushbuttons, SIM900A module, and the 16x2 I2C LCD display in these functions.