Circuit Documentation

Summary of the Circuit

This circuit is designed to control a water pump using an ESP8266 NodeMCU microcontroller. The ESP8266 NodeMCU is powered by a 3.3V supply derived from a 12V battery through an XL4015 5A DC Buck Step-down converter. The microcontroller interfaces with a KF-301 relay to switch the water pump on and off. The relay is used to isolate the microcontroller from the high-power circuit of the water pump, which is also powered by a 12V battery.

Component List

ESP8266 NodeMCU

• Description: A Wi-Fi capable microcontroller module based on the ESP8266 chip.
• 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

12V Battery

• Description: A power source for the circuit.
• Pins: VCC, GND

XL4015 5A DC Buck Step-down Converter

• Description: A module that steps down the voltage from 12V to a lower voltage.
• Pins: Output +, Output -, Input +, Input -

Water Pump

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

KF-301 Relay

• Description: An electromechanical switch used to control a high power circuit with a low power signal.
• Pins: signal, power, ground, NC, C, NO

Wiring Details

ESP8266 NodeMCU

• 3V3: Connected to the power pin of the KF-301 Relay and the Output + of the XL4015 DC Buck Step-down Converter.
• GND: Connected to the ground pin of the KF-301 Relay and the Output - of the XL4015 DC Buck Step-down Converter.
• D6: Connected to the signal pin of the KF-301 Relay.

12V Battery

• VCC: Connected to the common (C) pin of the KF-301 Relay and the Input + of the XL4015 DC Buck Step-down Converter.
• GND: Connected to the ground (GND) pin of the Water Pump and the Input - of the XL4015 DC Buck Step-down Converter.

XL4015 5A DC Buck Step-down Converter

• Output +: Connected to the 3V3 pin of the ESP8266 NodeMCU.
• Output -: Connected to the GND pin of the ESP8266 NodeMCU.
• Input +: Connected to the VCC pin of the 12V Battery.
• Input -: Connected to the GND pin of the 12V Battery.

Water Pump

• VCC: Connected to the normally open (NO) pin of the KF-301 Relay.
• GND: Connected to the GND pin of the 12V Battery.

KF-301 Relay

• signal: Connected to the D6 pin of the ESP8266 NodeMCU.
• power: Connected to the 3V3 pin of the ESP8266 NodeMCU.
• ground: Connected to the GND pin of the ESP8266 NodeMCU.
• NC: Not connected in this circuit.
• C: Connected to the VCC pin of the 12V Battery.
• NO: Connected to the VCC pin of the Water Pump.

Documented 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

(No additional documentation provided)