Circuit Documentation

Summary

The circuit in question is designed to harness solar energy using a solar panel, manage the power with a solar charge controller, and store it in a 12V 7Ah battery. The system includes an Automatic Transfer Switch (ATS) to switch between solar and AC power sources, ensuring continuous power supply. The circuit also features a DC-DC boost converter to step up voltage where necessary, and a Mini AC-DC module to convert AC to a regulated 5V DC supply.

For communication, a SIM900A module is included, interfacing with an ESP32 microcontroller, which is the central processing unit of the circuit. The ESP32 also connects to various sensors and output devices, including an MQ-136 hydrogen sulfide gas sensor, a temperature sensor (TEMP), an LCD display, a flame sensor (Sensor SHT113), and two 12V blue LEDs. A buzzer module provides audible alerts. Diodes are used throughout the circuit for directional current flow and protection.

Component List

Solar Panel

• Description: A photovoltaic panel for converting sunlight into electrical energy.
• Pins: +, -

12V 7Ah Battery

• Description: A rechargeable battery for energy storage.
• Pins: 12V +, 12V -

Solar Charge Controller

• Description: Regulates the energy flow from the solar panel to the battery and load.
• Pins: Solar Cell +, Solar Cell -, Battery +, Battery -, Load +, Load -

ATS (Automatic Transfer Switch)

• Description: Switches between solar and AC power sources.
• Pins: +, -

AC Source

• Description: An alternate source of AC power.
• Pins: -, +

DC-DC Boost Converter

• Description: Steps up the voltage to a higher level.
• Pins: VIN-, VIN+, VOUT+, VOUT-

SIM900A

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

Diode

• Description: Allows current to flow in one direction only.
• Pins: cathode, anode

ESP32-WROOM-32UE

• Description: A microcontroller with Wi-Fi and Bluetooth capabilities.
• Pins: 3v3, EN, VP, VN, 34, 35, 32, 33, 25, 26, 27, 14, 12, GND, 13, D2, D3, 5V, 23, 22, TX, RX, 21, 19, 18, 5, 17, 16, 4, 0, 2, 15, D1, D0, CKL

MQ-136 Sensor Hydrogen Sulfide Gas

• Description: Detects the presence of hydrogen sulfide gas.
• Pins: VCC, GND, A0, D0

TEMP (Temperature Sensor)

• Description: Measures ambient temperature.
• Pins: 5V, D3, GND

LCD Display 16x4 I2C

• Description: An alphanumeric display with I2C interface.
• Pins: SCL, SDA, VCC, GND

Sensor SHT113 Flame

• Description: Detects the presence of flames or fire.
• Pins: A0, D0, GND, VCC

12V Blue LED

• Description: A light-emitting diode for indication purposes.
• Pins: GND, VCC

Buzzer Module

• Description: Provides audible alerts.
• Pins: GND, Vcc, I/O

Mini AC-DC 110V-230V to 5V 700mA Module

• Description: Converts AC power to a regulated 5V DC supply.
• Pins: GND, 5v, Neutral, Life

Wiring Details

Solar Panel

• + to Solar Charge Controller Solar Cell +
• - to Solar Charge Controller Solar Cell -

12V 7Ah Battery

• 12V + to Solar Charge Controller Battery +
• 12V - to Solar Charge Controller Battery -

Solar Charge Controller

• Load + to ATS +
• Load - to ATS -

ATS

• + to Mini AC-DC Module 5v
• - to Mini AC-DC Module GND

AC Source

• - to Mini AC-DC Module Neutral
• + to Mini AC-DC Module Life

DC-DC Boost Converter

• VIN- to ATS - through Diode (anode)
• VIN+ to ATS +
• VOUT+ to Diode (anode)
• VOUT- to Diode (anode)

SIM900A

• GND to ESP32 GND
• 5V to Diode (anode)
• VCC to TEMP 5V and ESP32 5V
• 5VT to ESP32 TX
• 5VR to ESP32 RX

Diode

• Multiple diodes used for directional current flow and protection.

ESP32-WROOM-32UE

• VN to Diode (cathode)
• 33 to MQ-136 A0
• 27 to LCD Display SCL
• 14 to LCD Display SDA
• 12 to MQ-136 D0
• GND to various components' GND
• 5V to SIM900A VCC
• 18 to 12V Blue LED VCC
• 5 to 12V Blue LED VCC
• 4 to TEMP D3
• 0 to Sensor SHT113 Flame D0
• 2 to Sensor SHT113 Flame A0
• 15 to Buzzer Module I/O

MQ-136 Sensor Hydrogen Sulfide Gas

• VCC to DC-DC Boost Converter VOUT+
• GND to DC-DC Boost Converter VOUT-

TEMP (Temperature Sensor)

• 5V to SIM900A VCC
• D3 to ESP32 4
• GND to ESP32 GND

LCD Display 16x4 I2C

• SCL to ESP32 27
• SDA to ESP32 14
• VCC to DC-DC Boost Converter VOUT+
• GND to DC-DC Boost Converter VOUT-

Sensor SHT113 Flame

• A0 to ESP32 2
• D0 to ESP32 0
• GND to ESP32 GND
• VCC to SIM900A 5V

12V Blue LED

• GND to ESP32 GND
• VCC to ESP32 18 and 5

Buzzer Module

• GND to Diode (cathode)
• Vcc to Diode (anode)
• I/O to ESP32 15

Documented Code

No code was provided for the microcontrollers in the circuit. If code becomes available, it should be documented here with explanations for each function and routine, including setup and loop structures, interrupt service routines, and any communication protocols implemented.