The ESP32 ArduinoCore Interface for OneWire (OW) communication protocol is a crucial aspect of interfacing with digital temperature sensors like the DS18B20. This interface allows the ESP32 microcontroller to communicate with one or more DS18B20 temperature sensors using the OneWire protocol.
Declares a function to print the temperature of a device with the given address.
void loop(void)
Begins the loop function, which runs continuously after setup.
sensors.requestTemperatures();
Requests temperature readings from all connected devices on the bus.
for(int i=0;i<numberOfDevices; i++)
Loops through each temperature device found on the bus.
printTemperature(tempDeviceAddress);
Prints the temperature of the i-th device.
void printAddress(DeviceAddress deviceAddress)
Declares a function to print the address of a device.
Functionality of
Initialization: The interface initializes the OneWire communication by defining the GPIO pin to which the OneWire data wire is connected. It also initializes the DallasTemperature library, which simplifies communication with DS18B20 sensors.
Device Detection: Upon initialization, the interface detects the number of DS18B20 sensors connected to the OneWire bus. It retrieves the unique address of each sensor and sets their resolution if detected.
Temperature Reading: The interface periodically requests temperature readings from all connected DS18B20 sensors. It then retrieves the temperature data and converts it to Celsius and Fahrenheit scales for further processing or display.
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.
Note : You can use arduino example code instead of below code because both are same (File > Example > WiFi> WiFiScan)
/* https://aruneworld.com/embedded/espressif/esp32
* Tested By : Arun(20170429)
* Example Name : AEW_WiFi_Scan.ino
* This sketch demonstrates how to scan WiFi networks.
* The API is almost the same as with the WiFi Shield library,
* the most obvious difference being the different file you need to include:
*/
#include "WiFi.h"
void setup()
{
Serial.begin(115200);
// Set WiFi to station mode and disconnect from an AP if it was previously connected
WiFi.mode(WIFI_STA);
WiFi.disconnect();
delay(100);
Serial.println("Setup done");
}
void loop()
{
Serial.println("scan start");
// WiFi.scanNetworks will return the number of networks found
int n = WiFi.scanNetworks();
Serial.println("scan done");
if (n == 0) {
Serial.println("no networks found");
} else {
Serial.print(n);
Serial.println(" networks found");
for (int i = 0; i < n; ++i) {
// Print SSID and RSSI for each network found
Serial.print(i + 1);
Serial.print(": ");
Serial.print(WiFi.SSID(i));
Serial.print(" (");
Serial.print(WiFi.RSSI(i));
Serial.print(")");
Serial.println((WiFi.encryptionType(i) == WIFI_AUTH_OPEN)?" ":"*");
delay(10);
}
}
Serial.println("");
// Wait a bit before scanning again
delay(5000);
}
This article is a continuation of the series on the ESP32 ArduinoCore Project using the ESP32 Dev board and carries the discussion on WiFi Web Server LED Blink. This series aims to provide easy and practical examples that anyone can understand. In our previous tutorial, we saw how to use the inbuilt code to toggle the onboard LED. This is the ESP32 LED Blinky in Wifi Webserver In this tutorial
A simple web server that lets you blink an LED via the web.
Wifi Web Server Info
This code will print the IP address of your WiFi Module (ESP32) (once connected) to the Serial monitor.
From that IP Address, you can open that address in a web browser to turn on and off the LED on pin-5.
If the IP address of your ESP32 is 192.168.1.143:
http://192.168.1.143/H turns the LED on
http://192.168.1.143/L turns it off
This example is written for a network using WPA encryption.
For WEP or WPA, change the Wifi.begin() call accordingly.
When programming the ESP32 using the Arduino IDE, you typically use the ESP32 Arduino core, which provides a set of libraries and APIs to facilitate development. In this tutorial, we can discuss ESP32 ArduinoCore Interface Basic Example of Serial, GPIO, Timer, etc
Explore the fundamental features of the ESP32 microcontroller through an introductory example utilizing the ArduinoCore interface. This tutorial covers Serial communication, GPIO configuration for digital input and output, and Timer usage for precise timing operations. Ideal for beginners and hobbyists, this basic example demonstrates how to implement essential functionalities such as blinking an LED, reading button inputs, and handling timer interrupts, providing a solid foundation for further exploration and development with the ESP32 platform.”
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