SunFounder ESP32 User Manual

SunFounder ESP32 Starter Kit
There is a fixed frequency oscillator, which is built with a 555 timer IC. The generated square wave is then fed to the
sensor like a capacitor. However, for the square wave signal, the capacitor has a certain reactance or, for the sake of
argument, a resistor with a pure ohmic resistor (10k resistor on pin 3) to form a voltage divider.
The higher the soil moisture, the higher the capacitance of the sensor. As a result, the square wave has less reactance,
which reduces the voltage on the signal line, and the smaller the value of the analog input through the microcontroller.
Specification
• Operating Voltage: 3.3 ~ 5.5 VDC
• Output Voltage: 0 ~ 3.0VDC
• Operating Current: 5mA
• Interface: PH2.0-3P
• Dimensions: 3.86 x 0.905 inches (L x W)
• Weight: 15g
Example
• 5.9 Measure Soil Moisture (Arduino Project)
750 Chapter 5. Learn about the Components in Your Kit

SunFounder ESP32 Specifications

General

Microcontroller	ESP32
Clock Speed	Up to 240MHz
Flash Memory	4MB
SRAM	520KB
Wi-Fi	802.11 b/g/n
GPIO Pins	36
ADC	12-bit
PWM Channels	16
Operating Voltage	3.3V
DC Current per I/O Pin	40mA
USB	Micro USB
Bluetooth	Bluetooth 4.2 BR/EDR and BLE
Analog Input Pins	18
DAC Pins	2
CPU	Xtensa dual-core 32-bit LX6