I got a request, to design and build an electronic metronome. You can find several on the market, but the problem it is ether producing voice or the classical mechanical metronome. The requirement here was a visual effect. To be precise four LEDs for 4/4 beat. It is required for drumming where you have no chance to hear the clicking (or maybe just through headphones).
The 2 down sides to my ZeroBoy build I did recently were that it didn’t have a build in battery power and that it didn’t have sound. I seen that the MintyPi was using a USB sound card to give their handheld a speaker by soldering a speaker to the 3.5mm jack. So I thought I could do the same to add sound to my ZeroBoy.
I’m making great progress with the firmware for the new Mini Sumo Robot (see “New Concept for 2018 Mini Sumo Roboter“). The goal is a versatile and low-cost Mini Sumo robot, and the robot comes with the feature of magnetic position encoders. In a previous article I have explained how to mold custom tires for robots (see “Making Perfect Sticky DIY Sumo Robot Tires“), this article is about how to make DIY Magnetic disk encoders.
Rui Santos over at Random Nerd Tutorials posted a step by step guide on building an ESP8266 Wi-Fi button:
In this project you’re going to build an ESP8266 Wi-Fi Button that can trigger any home automation event. This is like a remote control that you can take in your pocket or place anywhere that when pressed sends out an email. It can also be called a DIY Amazon Dash Button clone.
On newer DPS:es, the SWD connector is a JST-GH (1.25mm spacing that is) which translates to “really tiny”. The annular rings where you need to apply solder and heat for adding wires are even smaller. This is why the OpenDPS SWD Bottle is handy. Add three P50-E2 pogo pins, and connect to your favourite SWD debugger.
For once, this project was not for me… it was for my wife !
Every morning she takes the bus then train to go to work. If she misses her train, she has to wait for more than 30 minutes for the next one. Not missing her bus is therefore quite important.
Where we live every bus station has a display letting you know in real time when the next bus will be there. My first thought was to reverse engineer its RF signal but something easier then came to mind.
In the very same bus stations, a small QR code brings you to a web page displaying the very same “minutes before bus arrival”… HTML parsing therefore made more sense given that I was fairly busy with other projects.
This is complete project for 1×6 antenna switch. It was bult in more than 50 pieces around the world and performs really good. Even big guns use it for their systems. The project was designed with help from other OMs (S55O, S59MA, S50LD, S51CT, S51ZJ, SM2WMV/SJ2W and others).
Above — All 4 boards were built in re-purposed Hammond boxes. A PIC-based counter sits on top of the offset mixer. I build modular gear and this allows modification and fosters experimentation. When I build a final transistor radio receiver, I plan to place the offset mixer, PLL circuitry and VXO on the same board inside the radio with some shielding. My VCOs always go in a RF tight container. A 0.0033 µF feed through capacitor connects the VCO varactors to the outside world.
This one is simple and does not require any expensive Teensy’s or STM32.
It runs on the ATtiny85 using V-USB.
The ATtiny is programmed with the Micronucleus bootloader and is firmware