I always wonder whether it is possible to make an amplifier of class D on ATtiny13 or not. Some time ago I found George Gardner’s project based on ATtiny85 – TinyD. It was a sign to start challenging it with ATtiny13. It took me a few hours but finally I made it! The code is very short and useses a lot of hardware settings which has been explained line-by-line in the comments. The project runs on ATtiny13 with maximum internal clock source (9.6MHz). It gave me posibility to use maximum of hardware PWM frequency (Fast PWM mode).
My goals include:
1. The ability to switch each device on/off with a rocker or toggle switch
2. Current limiting capability via a fuse or similar device
3. Overvoltage protection
4. Visual indicator (LED) of operational status
5. Multiple independent outlet
The VEML6075 senses UVA and UVB light and incorporates photodiode, amplifiers, and analog / digital circuits into a single chip using a CMOS process. When the UV sensor is applied, it is able to detect UVA and UVB intensity to provide a measure of the signal strength as well as allowing for UVI measurement.
This application note summarizes the international safety standards and certifications that apply to digital isolators. Link here
Digital isolators provide signal isolation and the level shifting required for the correct operation of many circuits. Equally important, they insulate the user from electric shock. With basic human safety considerations so pertinent here, these isolators must undergo extensive testing and certification to ensure user safety. This article briefly summarizes the international safety standards and certifications that apply to digital isolators. An example exercise using the MAX1493x family shows how an IC designer must use a data sheet and the standard’s specification tables to determine which digital isolator will be optimal for an application.
There are many ways to measure radioactivity level, semiconductor detectors sense interactions between ionizing radiation and p-n junction. Because in hobbyist area most popular are Geiger-Muller based detectors (in short: not a semiconductor but lamp based devices), I think it’s a cool idea to take a look at this approach.
In this post I will present such home-made sensor and a set of software to parse collected results.
Recently I started work on a new board. This one will be a front door entry system, so I decided to go with something that could read my NFC implant but also had a numeric keypad for the kids (and anyone else) to use. Not everyone wants to be chipped. Crazy, isn’t it? I’ll write more up on the board when it gets closer to completion, but for this post I’m going to concentrate on a small PCB antenna that’s intended for use with a tiny implanted tag. I’ve successfully used a wirewound inductor before, but I decided it was time to try a PCB trace antenna. This is the most common way to make an NFC reader, but nobody seems to have tried to tune one for an implant – probably because it means it will be worse at reading larger tags. Anyway, this is about creating a small PCB antenna and more importantly tuning it so that it read well.
App note from Precision Microdrives on how to properly connect wires on to vibration motors for reliability. Link here
Vibration motors require electrical power, which must be delivered by wires or PCB tracks to the motor. Precision Microdrives vibrating motors are available in a range of connector forms. From stock, they are available with factory installed leads, terminals, PCB solder pins, or as PCB SMT / SMD options. Solder pins and SMT motors have the advantage of being mounted directly onto the PCB which simplifies the connection process.
All about vibration motors and how its frequency and amplitude be controlled in this app note from Precision Microdrives. Link here
We’re often asked how to adjust the vibration amplitude or frequency of our various vibration motors. In this article, we’ll look at how simple it is, why it can be useful, and how we can predict the behaviour of a motor using the driving voltage and Typical Performance Characteristics graph.
This blog post is a continuation of my two earlier GPSDO blog posts. The first one (from a few years back) details a simple Frequency-Locked Loop GPSDO design, based around an Arduino processor. The second (more recent) blog post discusses simulating Brooks Shera’s GPSDO algorithm (from the July, 1998 issue of QST) using The MathWorks Simulink program.
This third blog posts describes my modification of my original Frequency-Locked Loop (FLL) GPSDO to be a Phase-Locked Loop (PLL) GPSDO, and it includes the hardware schematics, Simulink models, and the Arduino code I wrote to implement Brooks Shera’s GSPDO algorithm on an Arduino processor.