Circuit Documentation

Summary of the Circuit

This circuit is designed to control a water pump using an Arduino UNO microcontroller. The Arduino UNO is interfaced with a SIM800L GSM module for communication purposes and a 5V relay to control the power to the water pump. The power for the SIM800L module is supplied by a Polymer Lithium Ion Battery, while the water pump and the relay are powered by two 18650 batteries. The relay acts as an electrically operated switch that allows the Arduino to control the high-power circuit of the water pump.

Component List

Arduino UNO

• Description: A microcontroller board based on the ATmega328P.
• Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0-A5, SCL, SDA, AREF, D0-D13.

5V Relay

• Description: An electromechanical switch used to control a high power circuit with a low power signal.
• Pins: Normally Open, Common terminal, Normally Closed, In, GND, VCC.

Water Pump

• Description: An electric pump for moving water.
• Pins: VCC, GND.

2x 18650 Batteries

• Description: A pair of rechargeable lithium-ion batteries.
• Pins: VCC, GND.

SIM800L GSM Module

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

Polymer Lithium Ion Battery - 850mAh

• Description: A rechargeable battery used to power small electronics.
• Pins: VCC, GND.

Wiring Details

Arduino UNO

• 5V to 5V Relay VCC
• GND to SIM800L GND, Polymer Lithium Ion Battery GND, and 5V Relay GND
• D11 to SIM800L RXD
• D10 to SIM800L TXD
• D8 to 5V Relay In

5V Relay

• VCC from Arduino UNO 5V
• GND from Arduino UNO GND
• In from Arduino UNO D8
• Normally Open to 2x 18650 Batteries GND
• Common terminal to Water Pump GND

Water Pump

• VCC from 2x 18650 Batteries VCC
• GND to 5V Relay Common terminal

2x 18650 Batteries

• VCC to Water Pump VCC
• GND to 5V Relay Normally Open

SIM800L GSM Module

• GND from Arduino UNO GND
• VCC from Polymer Lithium Ion Battery VCC
• RXD from Arduino UNO D11
• TXD to Arduino UNO D10

Polymer Lithium Ion Battery - 850mAh

• VCC to SIM800L VCC
• GND to Arduino UNO GND

Documented Code

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:

}

Additional Notes

• The code provided for the Arduino UNO is a template with empty setup and loop functions. The actual implementation should include initialization of the SIM800L module and control logic for the relay to turn the water pump on and off based on the desired conditions.
• The SIM800L module requires additional setup for GSM communication which is not included in the provided code.
• The relay control pin (D8) should be set as an output in the setup function and controlled in the loop function to activate the water pump.
• Safety measures should be considered when interfacing with high-power devices like the water pump to prevent damage to the microcontroller and other components.