Circuit Documentation

Summary

This document provides a detailed overview of a circuit that includes an Arduino UNO, a Sim800l GSM module, a DS3231 RTC module, resistors, and a Li-ion battery. The circuit is designed to interface these components for various functionalities, including timekeeping and GSM communication.

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

Sim800l

• Description: A GSM/GPRS module for communication.
• Pins: NET, RST, VCC, RXD, TXD, GND

Resistor (10k Ohms)

• Description: A resistor with a resistance of 10k Ohms.
• Pins: pin1, pin2

Resistor (20k Ohms)

• Description: A resistor with a resistance of 20k Ohms.
• Pins: pin1, pin2

Li-ion battery 18650-2000mAh 3.7V 7.4WH

• Description: A rechargeable lithium-ion battery.
• Pins: +, -

DS3231 RTC

• Description: A real-time clock module.
• Pins: 32K, SQW, SCL, SDA, VCC, GND

Wiring Details

Arduino UNO

• 5V connected to DS3231 RTC VCC
• GND connected to DS3231 RTC GND, Resistor (20k Ohms) pin1, Sim800l GND, Li-ion battery -
• A4 connected to DS3231 RTC SDA
• A5 connected to DS3231 RTC SCL
• D3 connected to Resistor (10k Ohms) pin1
• D2 connected to Sim800l TXD

Sim800l

• GND connected to Arduino UNO GND, Resistor (20k Ohms) pin1, Li-ion battery -
• VCC connected to Li-ion battery +
• RXD connected to Resistor (10k Ohms) pin2, Resistor (20k Ohms) pin2
• TXD connected to Arduino UNO D2

Resistor (10k Ohms)

• pin1 connected to Arduino UNO D3
• pin2 connected to Resistor (20k Ohms) pin2, Sim800l RXD

Resistor (20k Ohms)

• pin1 connected to Arduino UNO GND, DS3231 RTC GND, Sim800l GND, Li-ion battery -
• pin2 connected to Resistor (10k Ohms) pin2, Sim800l RXD

Li-ion battery 18650-2000mAh 3.7V 7.4WH

• + connected to Sim800l VCC
• - connected to Arduino UNO GND, DS3231 RTC GND, Resistor (20k Ohms) pin1, Sim800l GND

DS3231 RTC

• VCC connected to Arduino UNO 5V
• GND connected to Arduino UNO GND, Resistor (20k Ohms) pin1, Sim800l GND, Li-ion battery -
• SDA connected to Arduino UNO A4
• SCL connected to Arduino UNO A5

Code Documentation

Arduino UNO Code

sketch.ino

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

}

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

}

documentation.txt

This document provides a comprehensive overview of the circuit, including the components used, their connections, and the code running on the Arduino UNO.