Articles about ESP32

How to show the temperature and humidity of your room on a Heltec WiFi Kit 32 attached to a DHT11 / DHT22 sensor

When you have a DHT11 / DHT22 sensor, you can measure the temperature and humidity of your room. If you attach the sensor to a Heltec WiFi Kit 32 development board, you will be able to put up the readings on a 0.96 Inch OLED screen.

Given these points, let’s look at how we can show the temperature and humidity readings of your room on a Heltec WiFi Kit 32 development board attached to a DHTXX sensor.

How to setup MicroPython WebREPL on your ESP32 development board

When I wrote about setting up MicroPython on an ESP development board, I came across the WebREPL.

If you setup MicroPython WebREPL on your ESP32 board, then you can interact with your ESP32 board wirelessly.

In case you need it, this is how to setup MicroPython WebREPL on your ESP32 development board.

How to setup MicroPython on your ESP32 development board to run Python applications

When my friend Youssef shared a link to MicroPython, I kept it at the back of my mind. Since I had found some time to sharpen my saw, I decided to take a look at it.

If I get familiar MicroPython, then I can perform machine learning magic with an AIOT board like Sipeed Maixduino Kit with greater ease.

Given that in mind, here are the steps that I took to setup MicroPython on my ESP32 development board to kickstart my learning.

In case you wish to setup MicroPython on your ESP32 development board to run Python applications, read on to find out more.

How to post JSON data to a HTTP server endpoint from your ESP32 development board with ArduinoJson

When sending data from your ESP32 development board, you may choose to send the data in JSON.

In such a situation, you can consider using ArduinoJson to help you construct the JSON data.

Given that, let us look at how we can post JSON data to a HTTP server endpoint from a ESP32 development board with ArduinoJson.

How to send a HTTP Basic Authentication request from your ESP32 development board

When you connect your ESP32 board to the internet, you may need to send HTTP Basic Authentication requests.

In this situation, we can rely on the HttpClient library from the Arduino core for ESP32.

Given that, this post shows how you can send a HTTP Basic Authentication request from your ESP32 development board.

How to control a servo motor with an ESP32 development board

When I try to reuse the Ardunio Sketch to control a servo motor with a ESP8266, I encountered the following error during compile time:

WARNING: library Servo claims to run on (avr, sam, samd, nrf52, stm32f4) architecture(s) and may be incompatible with your current board which runs on (esp32) architecture(s).
In file included from /Users/i309663/Documents/learning/Arduino-sketches/sketch_arduino_servo/sketch_arduino_servo.ino:1:0:
/Users/i309663/Arduino.1.8.7/Arduino.app/Contents/Java/libraries/Servo/src/Servo.h:73:2: error: #error “This library only supports boards with an AVR, SAM, SAMD, NRF52 or STM32F4 processor.”
#error “This library only supports boards with an AVR, SAM, SAMD, NRF52 or STM32F4 processor.”
^
exit status 1
Error compiling for board ESP32 Dev Module.

Therefore, I had to find another way to control my SG90 servo motor with an ESP32 development board.

Given that, this post shows how to control a servo motor with an ESP32 development board.

How to use an ESP32 development board to read from a VCNL4010 Proximity/Light sensor

If you have a Proximity/Light sensor, you will be able to detect how close an object is. When your range of detection is within 200mm, you can use the VCNL4010 Proximity/Light sensor.

Given that characteristic, you can use the VCNL4010 Proximity/Light sensor as a contactless switch to trigger some action.

For example, you can use it in a soap dispenser that will dispense some soap when a palm is near the nozzle.

In case you need it, this is how to use an ESP32 development board to read from a VCNL4010 Proximity/Light sensor.

How to use an ESP32 development board to read RFID tags from a SparkFun RFID USB Reader

When you have an RFID starter kit from Sparkfun, you will be able to read RFID tags through a serial connection.

Although the SparkFun RFID USB Reader comes with a USB port, you can also read RFID tags with an ESP32 development board.

In case you need it, this is how to use an ESP32 development board to read RFID tags from a SparkFun RFID USB Reader.

How to write a C# program to communicate with an ESP32 development board via Bluetooth Serial

Coupled with Bluetooth Serial and GPIO pins, ESP32 can augment a Windows machine with the ability to read from sensors.

So with an ESP32 development board, you can turn your old Windows machine into an IOT gateway that can sense its operating environment.

Given these points, let us look at how we can write a C# program to communicate with an ESP32 development board via Bluetooth Serial.