A PulseSensor library with popular sensor manufactured by PulseSensor.com (or it's cheaper China clone) exists for Arduino that can detect pulse. Optical heart rate sensors use a methodology called photoplethysmography (PPG) to measure heart rate. A photoplethysmogram (PPG) can detect blood volume changes in the microvascular bed of tissue. A photoplethysmography is obtained by using a pulse … [Read more...]
Visual Programming for Arduino Compatible Boards
Our regular reader already used IBM NodeRED with ESP32 for our few IoT guides. That NodeRED is one example of visual programming system. Visual programming language (VPL) let us create programs by graphically interacting rather than textual coding. Visual programming is not a new concept but goes back to the 70s. Graphical interaction includes spatial arrangements of text and graphic symbols, and … [Read more...]
Over-the-Air Programming (OTA) and Arduino
Over-the-Air Programming (OTA) includes different methods of software, settings distribution and not limited to development board but includes the consumer devices such as smartphones, set-top boxes. With Over-the-Air Programming (OTA), from one central console we can send an update to all the devices. Related terminologies are over-the-air service provisioning (OTASP), over-the-air provisioning … [Read more...]
CircuitPython vs C/C++ vs Lua for the Microcontrollers
While programming languages can not be compared, specially when they are diverse in basic nature like Python vs C/C++ or Lua with them yet the question of comparison arises. Investing time behind anything should have a goal. While MicroPython, CircuitPython variations of Python has been discussed on this website and the problems of Arduino "langugage" discussed, place of C/C++ in the world of … [Read more...]
ESP32 MicroPython Setup with Adafruit Ampy
Previously we discussed basics around MicroPython and also configured to run MicroPython via IDE. Here is ESP32 MicroPython Setup with Adafruit Ampy for Windows, MacOS X and Linux. You need Python needs to be running and install few tools. An important note for this guide is to use the default command line tool for installation of Python packages such as Command Prompt for Microsoft Windows (do … [Read more...]
ESP32 Arduino : What is SPI Flash File System (SPIFFS)
The SPI Flash File System or SPIFFS is a light-weight file system for microcontrollers with an SPI flash chip. A flash file system is designed for storing files on flash memory–based storage devices optimized for the particular system. SPI stands for Serial Peripheral Interface. Flash memory is a type of non-volatile storage that is electrically eraseable and rewriteable. Flash memory is a kind … [Read more...]
How to Send Data from Arduino to MySQL Database
In our recent past discussions, we have send data from ESP32 Arduino to IBM Watson IoT by either using MQTT or by using HTTP POST. In the same way, we have discussed how with CouchDB we can send data from ESP32 Arduino. Also, we have discussed different types of cloud database for IoT. MySQL is widely used database for PHP driven web applications. We can send data from Arduino, ESP32 to MySQL … [Read more...]
Contact Bounce of Pushbuttons and Arduino ESP32 Debounce
No surface is perfectly smooth and inelastic. When two surfaces of pushbutton comes together with any force, there is kinetic energy that makes ringing. In one older article we talked about different types of switches. That basic idea and terminogies required to be known for this article on the phenomenon contact bounce of pushbuttons and counteracting with software library. Contact bounce is a … [Read more...]
Writing to CouchDB/Cloudant From ESP32 Arduino
You'll not get full working code in this guide but get full hints of code, resources. This guide will help to learn our regular readers in opposite direction of learning. Methodology is exactly like we did with Watson IoT platform (our GitHub repo has four sample codes). Here Are Some Tips, Resources For Writing to CouchDB/Cloudant From ESP32 Arduino. Our regular readers can recall about HTTP Post … [Read more...]
ESP32 Arduino Built-in Hall Sensor Code & Theory
ESP32 has a Hall Effect Sensor near pin 22, just below and middle of the inscription "ESP32-WROOM-32", inside the metal cover. Hall effect sensors measure the magnitude of a magnetic field as output voltage. Hall effect sensors are used for proximity sensing, positioning, speed detection, and current sensing applications. Hall sensor when combined with threshold detectors act as a switch. That is … [Read more...]
How to Invert Signal for Arduino (HIGH to LOW or the Reverse)
Such need is common when then need interfacing for IoT with household gadgets. Here is How to Invert Signal for Arduino (HIGH to LOW or the Reverse). One way is using some kind of relay module, which we described in our guide to interface with doorbell. This is normally a problem with devices that are active LOW. Since most devices are active HIGH, meaning they are triggered by a HIGH voltage, … [Read more...]