Circuit Documentation

Summary

This document provides a detailed overview of a circuit that includes an ESP8266 NodeMCU, a SIM800L GSM module, a 16x2 I2C LCD, a GPS NEO 6M module, an LM2596 step-down module, a 2x 18650 battery pack, a pushbutton, a piezo buzzer, and a rocker switch. The circuit is designed to integrate these components to perform various functions, including wireless communication, GPS tracking, and user interaction through a button and display.

Component List

ESP8266 NodeMCU

• Description: A low-cost Wi-Fi microcontroller with GPIO, PWM, ADC, I2C, and UART capabilities.
• Pins: D0, D1, D2, D3, D4, 3V3, GND, D5, D6, D7, D8, RX, TX, A0, RSV, SD3, SD2, SD1, CMD, SD0, CLK, EN, RST, VIN

SIM800L

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

16x2 I2C LCD

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

GPS NEO 6M

• Description: A GPS module for location tracking.
• Pins: VCC, RX, TX, GND

LM2596 Step Down Module

• Description: A DC-DC buck converter for voltage regulation.
• Pins: OUT-, OUT+, IN-, IN+

2x 18650 Battery Pack

• Description: A battery pack holding two 18650 lithium-ion cells.
• Pins: vcc, gnd

Pushbutton

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

Piezo Buzzer

• Description: A piezoelectric buzzer for sound output.
• Pins: pin 1, pin 2

Rocker Switch (SPST)

• Description: A single-pole single-throw rocker switch.
• Pins: 1, 2

Wiring Details

ESP8266 NodeMCU

• D1 connected to Pushbutton Pin 4 (out)
• GND connected to Pushbutton Pin 2 (in)
• GND connected to Piezo Buzzer pin 2
• D2 connected to Piezo Buzzer pin 1
• VIN connected to LM2596 Step Down Module IN+ and Rocker Switch (SPST) pin 2
• GND connected to LM2596 Step Down Module IN- and 2x 18650 gnd
• D3 connected to 16x2 I2C LCD SCL
• D4 connected to 16x2 I2C LCD SDA
• D5 connected to Sim800l RXD
• D6 connected to Sim800l TXD
• D7 connected to GPS NEO 6M RX
• D8 connected to GPS NEO 6M TX

SIM800L

• VCC connected to LM2596 Step Down Module OUT+
• GND connected to LM2596 Step Down Module OUT-
• RXD connected to ESP8266 NodeMCU D5
• TXD connected to ESP8266 NodeMCU D6

16x2 I2C LCD

• VCC connected to LM2596 Step Down Module OUT+
• GND connected to LM2596 Step Down Module OUT-
• SDA connected to ESP8266 NodeMCU D4
• SCL connected to ESP8266 NodeMCU D3

GPS NEO 6M

• VCC connected to LM2596 Step Down Module OUT+
• GND connected to LM2596 Step Down Module OUT-
• RX connected to ESP8266 NodeMCU D7
• TX connected to ESP8266 NodeMCU D8

LM2596 Step Down Module

• OUT+ connected to GPS NEO 6M VCC, 16x2 I2C LCD VCC, Sim800l VCC
• OUT- connected to GPS NEO 6M GND, 16x2 I2C LCD GND, Sim800l GND
• IN+ connected to ESP8266 NodeMCU VIN and Rocker Switch (SPST) pin 2
• IN- connected to ESP8266 NodeMCU GND and 2x 18650 gnd

2x 18650 Battery Pack

• vcc connected to Rocker Switch (SPST) pin 1
• gnd connected to LM2596 Step Down Module IN- and ESP8266 NodeMCU GND

Pushbutton

• Pin 4 (out) connected to ESP8266 NodeMCU D1
• Pin 2 (in) connected to ESP8266 NodeMCU GND

Piezo Buzzer

• pin 2 connected to ESP8266 NodeMCU GND
• pin 1 connected to ESP8266 NodeMCU D2

Rocker Switch (SPST)

• pin 1 connected to 2x 18650 vcc
• pin 2 connected to ESP8266 NodeMCU VIN and LM2596 Step Down Module IN+

Documented Code

ESP8266 NodeMCU Code

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

}

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

}

16x2 I2C LCD Code

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

}

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

}

This documentation provides a comprehensive overview of the circuit, including the components used, their wiring details, and the code for the microcontrollers.