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 →
Converting LifeChat headset for external output and mic with Zoom and MS Teams
One thing that I've noticed since the pandemic started is that there are far more online meetings in general and also interviews on TV where the guest joins remotely via the web. I like both of these. While not having guests travel to studios is usually fine, sometimes I feel it could easily improved if... 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 →
Queuing files to the DFPlayer mp3 player module
In a previous post I presented how I use the DFPlayer module for playing audio files. In this one I'm going to share the code I use for the Arduino and DFPlayer to queue files. This allows files to be queued and played in sequence while the processor is doing other tasks. I've used this... Continue Reading →
Dimming 16×2 and 20×4 LCD displays
I recently built another clock. This time using a 16x2 LCD display with an I2C backpack. In know these displays are starting to look a bit dated, but I like them. I used a method of display large digits based on Ralph Bacon’s video #23 LCD BIG DIGITS for your Arduino using I2C - Easy!... Continue Reading →
MP3 DFPlayer notes: clones, noise, speakers, wrong file plays and no library
2 combined clock and timer projects using the DFPlayer modules I've used the DFPlayer mp3 player in a number of projects now, not as a music player, rather just for playing brief announcements in a timer and clock projects. The DFRobot site lists applications and they all appear to be for announcements, so theoretically it... Continue Reading →