Tag archive for: Internet of things

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 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 read RFID tags from SparkFun RFID USB Reader with Python 3

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

Previously, we saw how to use an ESP32 board to read RFID tags from a SparkFun RFID USB Reader.

Given that, I was able to build a ESP32 prototype to scan tag ids from RFID cards.

In order for that ESP32 prototype to recognise what each of my tag card represents, I need to label the ids. Whenever my ESP32 prototype gets a tag id, it will query a tag catalogue to see what that tag id represent.

Since it is easier to label the tag cards from a computer, I built a Python 3 application to read the RFID tags from the SparkFun RFID reader.

So how we can read RFID tags from SparkFun RFID USB Reader with Python 3?

If you are looking for a way to read RFID tags from SparkFun RFID USB Reader with Python 3, then this post is for you.

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.

ESP32 devkit-c v4 connected to sg90 servo motor

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.

VCNL4010 Proximity/Light sensor

How to use the MCP3008-I/P chip to help your Raspberry Pi read digital data from analog sensors

Although your Raspberry Pi is unable to read analog input out of the box, you can get a MCP3008 I/P ADC chip to help your Raspberry Pi do so.

MCP3008 IP ADC chip up close

When you connect a MCP3008 I/P chip to your Raspberry Pi, you can read up to 8 analog inputs with SPI.

Given these points, this post will show you how you can use the MCP3008 I/P chip to help your Raspberry Pi read digital data from analog sensors.

How to enable SPI master driver in Raspbian using raspi-config

Your Raspberry Pi has the ability to communicate with hardware using the Serial Peripheral Interface specification. However, this master driver is disabled by default.

If you want to use the SPI master driver to communicate with devices, then you will need to enable it.

Let’s look at how we can enable the SPI master driver using the Raspberry Pi Software Configuration Tool (raspi-config).

How to capture images in the dark with the Raspberry Pi Infrared Camera Module from Seeed Studio

When I wanted to keep tabs on my corridor, I built a Raspberry Pi Zero W surveillance camera with MotionEye and Raspbian Lite.

After a while, I make my Raspberry Pi Zero W see an ultra-wide view by using one of the Fish Eye lens from a Camera Lens kits that I received as a gift.

Since then, I am able to have a wide angle view of my corridor as long as I have a browser with an Internet connection.

However, the same setup will not work for checking on my plants in the kitchen. If I am to snap some pictures after my LED growth lights are switched off, I will definitely get pitch black images.

So what kind of camera should my plant surveillance setup use? In order to capture images in the dark, I should look for a camera without the Infrared Filter – a NoIR Camera.

With this in mind, I head over to Seeed Studio and got myself the Raspberry Pi Infrared Camera Module.

Since Seeed Studio had provided me with a voucher for this purchase, I am able to minimize the cost of producing this article.

Thank you Seeed Studio!

Given that, let’s see how we can capture images in the dark with the Raspberry Pi Infrared Camera Module.