I'm currently learning how to use the deep sleep functionality for ESP32. I've been following the excellent article by Random Nerd Tutorials ESP32 Deep Sleep with Arduino IDE and Wake Up Sources. I recommend this article if like me you are starting out with deep sleep with the ESP32. I want my ESP32 to wake... Continue Reading →
Converting raw data samples into meaningful results: Calibration and formula generation
So you have a sensor connected to your microcontroller. How do you calibrate it, particularly if the values from the sensor are not linear? That's a problem I have thought about before and it came up again yesterday when I wanted a project to monitor a battery voltage level. The current project that I am... Continue Reading →
Modifying a switched USB hub for project power distribution
Most of my projects are fairly simple, low powered and run off 5V. Until recently I've used a cheap USB hub plugged into an old iPad charger. This actually worked fairly well, other than the hub connections being a bit dodgy. However, I wanted to be able to switch individual items on and off. You... Continue Reading →
Experimenting with audio tones using the ESP32 for use in projects
A reader alerted me to the Tone function for Arduino. When I was making my WordPress hit counter I wanted to add in an audio alert. I preferred something other than a constant tone but thought I would have a go using the tone function. It turns out that the tone function is not implemented... Continue Reading →
Mini voltmeters with breadboard projects
When working with a project on a breadboard I've been caught with the supply voltage on the breadboard not being what I expected which resulted in the project not working as expected. To help prevent this I've bought some cheap mini 2 and 3 wire voltmeters. These sell for a couple of (AU) dollars. The... Continue Reading →
Using an ESP32 to get my WordPress viewing stats
I remember seeing an ESP8266 project years ago that displayed a Youtubers subscriber count on an LED display. I was really impressed by that project. Recently I wondered if a similar thing could be done with wordpress.com stats, in this case not showing subscribers, but daily views. I did come across this response to a... Continue Reading →
Batch processing files with Audacity
In my last post Using Text to Speech online tools to create audio files for Arduino projects I had some info about online text to audio sites I have been using to create audio alert files for projects. The files produced by ttsmp3.com seemed to have a lower audio level than I expected. I found... Continue Reading →
Using Text to Speech online tools to create audio files for Arduino projects
I’ve made a couple of projects that play audio alerts using a dfplayer and MP3 files. One in a clock that plays announcements and the other a countdown timer. When I did those, I used onlinetonegenerator.com to convert text to speech. I liked the voices but it doesn’t have an option to save the audio... Continue Reading →
Reliably debouncing rotary encoders with Arduino and ESP32
I love those simple cheap rotary encoders as used in the KY-040 modules as a method of getting user input with Arduino and ESP32 projects. The issue of bounce with them is significant and for years I’ve been looking a reliable method of dealing with it. I thought I had it figured out by either... Continue Reading →