Circuit Documentation

Summary

This circuit is designed to monitor soil moisture and control a water pump based on the readings. It uses an ESP32 microcontroller to read data from a DHT22 temperature and humidity sensor and a SparkFun Soil Moisture Sensor. The ESP32 also controls a water pump. Power is supplied through a 3.7V battery pack managed by a Battery Management System (BMS) and a Buck converter to step down the voltage.

Component List

ESP32 38 PINS

• Description: A versatile microcontroller with Wi-Fi and Bluetooth capabilities.
• Pins: GND, G23, G22, TXD, RXD, G21, G19, G18, G5, G17, G16, G4, G0, G2, G15, SDI, SD0, CLK, 3V3, EN, SP, SN, G34, G35, G32, 33, G25, G26, G27, G14, G12, G13, SD2, SD3, 5V

DHT22

• Description: A temperature and humidity sensor.
• Pins: +, Out, -

SparkFun Soil Moisture Sensor

• Description: A sensor to measure soil moisture levels.
• Pins: VCC, GND, SIG

Water Pump

• Description: A small water pump for irrigation.
• Pins: positive, negative

Buck Converter

• Description: A DC-DC converter to step down voltage.
• Pins: IN+, IN-, OUT+, OUT-

Rocker Switch (SPST)

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

Power Jack

• Description: A jack for connecting an external power source.
• Pins: POSITIF, NEGATIF

2.1mm DC Barrel Jack

• Description: A standard DC barrel jack.
• Pins: switch, sleeve, center

3.7V Battery

• Description: A 3.7V lithium-ion battery.
• Pins: +, -

BMS

• Description: A Battery Management System for managing multiple 3.7V batteries.
• Pins: B+, B2, B1, B-, P-, P+

Wiring Details

ESP32 38 PINS

• G13 connected to SIG of SparkFun Soil Moisture Sensor
• GND connected to:
  • - of DHT22
  • OUT- of Buck Converter
  • GND of SparkFun Soil Moisture Sensor
  • negative of Water Pump
• 5V connected to:
  • + of DHT22
  • OUT+ of Buck Converter
  • VCC of SparkFun Soil Moisture Sensor
• G5 connected to positive of Water Pump
• G35 connected to Out of DHT22

DHT22

• - connected to GND of ESP32
• + connected to 5V of ESP32
• Out connected to G35 of ESP32

SparkFun Soil Moisture Sensor

• SIG connected to G13 of ESP32
• GND connected to GND of ESP32
• VCC connected to 5V of ESP32

Water Pump

• positive connected to G5 of ESP32
• negative connected to GND of ESP32

Buck Converter

• IN+ connected to 1 of Rocker Switch
• IN- connected to NEGATIF of Power Jack
• OUT+ connected to 5V of ESP32
• OUT- connected to GND of ESP32

Rocker Switch (SPST)

• 1 connected to IN+ of Buck Converter
• 2 connected to POSITIF of Power Jack

Power Jack

• POSITIF connected to 2 of Rocker Switch
• NEGATIF connected to IN- of Buck Converter

3.7V Battery

• + connected to B+ of BMS
• - connected to + of another 3.7V Battery
• + of another 3.7V Battery connected to B2 of BMS
• - of another 3.7V Battery connected to + of another 3.7V Battery
• - of another 3.7V Battery connected to B- of BMS

BMS

• B+ connected to + of 3.7V Battery
• B2 connected to - of 3.7V Battery and + of another 3.7V Battery
• B1 connected to - of another 3.7V Battery and + of another 3.7V Battery
• B- connected to - of another 3.7V Battery
• P- connected to sleeve of 2.1mm DC Barrel Jack
• P+ connected to center of 2.1mm DC Barrel Jack

2.1mm DC Barrel Jack

• sleeve connected to P- of BMS
• center connected to P+ of BMS

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