The circuit in question is designed to interface various sensors and modules with an ESP32 microcontroller for the purpose of monitoring environmental parameters. The sensors include a DHT22 for temperature and humidity, a pH sensor for measuring the acidity or alkalinity of a solution, an NPK soil sensor for detecting the levels of nitrogen, phosphorus, and potassium in soil, and a capacitive soil moisture sensor. Additionally, an RS485 transceiver is used for long-distance communication, and a 0.96" OLED display is included for data visualization. The circuit is powered by a power supply unit, and voltage regulation is provided by two 7808 voltage regulators.
+
, Out
, -
+9volt
, output pin
, GND
12V DC
, A
, B
, GND
EN
, VP
, VN
, D34
, D35
, D32
, D33
, D25
, D26
, D27
, D14
, D12
, D13
, GND
, Vin
, D23
, D22
, TX0
, RX0
, D21
, D19
, D18
, D5
, TX2
, RX2
, D4
, D2
, D15
, 3V3
GND
, VCC
, AOUT
VCC
, RO
, RE
, GND
, B
, A
, DE
, DI
GND
, VDD
, SCK
, SDA
INPUT
, GND
, OUTPUT
+
, -
+
to ESP32 3V3
Out
to ESP32 D13
-
to GND+9volt
to ESP32 D34
output pin
(not connected)GND
to GND12V DC
to 7808 OUTPUT
A
to RS485 A
B
to RS485 B
GND
to GNDD34
to pH Sensor +9volt
D35
to Capacitive Soil Moisture Sensor AOUT
D13
to DHT22 Out
D23
to RS485 DI
D22
to RS485 RE
D19
to OLED SDA
D18
to OLED SCK
D4
to RS485 RO
D2
to RS485 DE
3V3
to DHT22 +
, Capacitive Soil Moisture Sensor VCC
, RS485 VCC
, OLED VDD
GND
to GNDAOUT
to ESP32 D35
VCC
to ESP32 3V3
GND
to GNDDI
to ESP32 D23
RE
to ESP32 D22
RO
to ESP32 D4
DE
to ESP32 D2
A
to NPK Soil Sensor A
B
to NPK Soil Sensor B
VCC
to ESP32 3V3
GND
to GNDGND
to GNDVDD
to ESP32 3V3
SCK
to ESP32 D18
SDA
to ESP32 D19
INPUT
to Power Supply +
GND
to GNDOUTPUT
to NPK Soil Sensor 12V DC
+
to 7808 INPUT
-
to GNDAll GND pins are interconnected and connected to the Power Supply -
.
No code has been provided for the microcontrollers in the circuit. When code is available, it should be documented here with explanations for each function and routine, including setup and loop functions for the ESP32 microcontroller, as well as any interrupt service routines or peripheral configurations.
Please note that the above documentation is based on the provided information and assumes that the circuit is correctly designed for the intended functionality. It is recommended to review the actual circuit and test it to ensure that it operates as expected.