ESP32 ArduinoCore Interface ADC

The “ESP32 ArduinoCore Interface – ADC” provides a seamless integration between the ESP32 microcontroller and the Arduino development environment, specifically focusing on the Analog-to-Digital Converter (ADC) functionality.

ADC

Term	Description
ADC	Analog-to-Digital Converter – A device or circuit that converts analog signals to digital data.
Functionality	Converts continuous analog signals into discrete digital values.
Process	Samples the analog input signal at regular intervals and quantizes the sampled values into digital values.
Applications	Used in microcontrollers, data acquisition systems, sensors, audio equipment, communication devices, and more.
Resolution	The number of digital bits used to represent the analog signal. Higher resolution ADCs provide more precise representations.
Sampling Rate	Determines how frequently the ADC samples the analog input signal. Higher sampling rates enable more accurate representation of fast-changing signals.
Types	Successive approximation, delta-sigma, pipeline, and flash ADCs are common types, each with specific advantages and applications.
Interface	Interfaces with digital systems such as microcontrollers or computers, where the digital output values can be processed or stored.

ADC Pins

Pin	ADC Channel	GPIO Number
GPIO32	ADC1_CH4	32
GPIO33	ADC1_CH5	33
GPIO34	ADC1_CH6	34
GPIO35	ADC1_CH7	35
GPIO36	ADC1_CH0	36
GPIO37	ADC1_CH1	37
GPIO25	ADC2_CH8	25
GPIO26	ADC2_CH9	26

This table lists the ADC pins available on the ESP32 microcontroller along with their corresponding ADC channels and GPIO numbers.

Code

/*
  AnalogReadSerial
  Reads an analog input on pin 0, prints the result to the serial monitor.
  Graphical representation is available using serial plotter (Tools > Serial Plotter menu)
  Attach the center pin of a potentiometer to pin A0, and the outside pins to +5V and ground.

  This example code is in the public domain.
*/

// the setup routine runs once when you press reset:
void setup() {
  // initialize serial communication at 9600 bits per second:
  Serial.begin(9600);
}

// the loop routine runs over and over again forever:
void loop() {
  
  // read the input on analog pin 0:
  int sensorValue = analogRead(A0);
  // print out the value you read:
  
  Serial.println(sensorValue);
  delay(1);        // delay in between reads for stability
}

Code Explanation of ESP32 ArduinoCore Interface ADC

Code Purpose: Reading an analog input from pin A0 and printing the value to the serial monitor.

Setup Routine: This part of the code initializes serial communication at a baud rate of 9600 bits per second.

   // the setup routine runs once when you press reset:
   void setup() {
     // initialize serial communication at 9600 bits per second:
     Serial.begin(9600);
   }

Loop Routine:

This section continuously reads the analog value from pin A0 using the analogRead() function.
It then prints the value to the serial monitor using Serial.println().
A small delay of 1 millisecond is added between reads for stability using delay().

   // the loop routine runs over and over again forever:
   void loop() {
     // read the input on analog pin 0:
     int sensorValue = analogRead(A0);
     // print out the value you read:
     Serial.println(sensorValue);
     delay(1);        // delay in between reads for stability
   }

Overall Functionality: This code can be useful for testing analog sensors or for basic data-logging applications.

Advantage of ESP32 ArduinoCore Interface ADC

Advantage	Description
Analog Signal Processing	ADCs enable microcontrollers to process analog signals from the physical world, converting them into digital values that can be processed by digital systems.
Sensor Interfacing	ADCs facilitate interfacing with various sensors that produce analog output, such as temperature sensors, light sensors, and pressure sensors, allowing accurate measurement and response to real-world phenomena.
Signal Conditioning	ADCs can be used for signal conditioning tasks, including amplification, filtering, and noise reduction, before converting analog signals to digital form, improving accuracy and reliability of measured data.
Data Acquisition	ADCs enable microcontrollers to acquire data from analog sources at high speeds and with high precision, suitable for applications such as data logging, instrumentation, and control systems.
Versatility	ADCs come in various resolutions, sampling rates, and input voltage ranges, allowing developers to choose the most suitable ADC for their specific application requirements.
Integration	Many microcontrollers, including the ESP32, feature built-in ADCs, eliminating the need for external ADC components and reducing system complexity and cost.