In this project, I mount the electronics from my single-key USB keyboard project to the back of an industrial mushroom push button switch. The finished big red button now activates my screensaver with a single overly-large button press. The biggest issues in this project were where to mount the USB electronics and how to connect the USB cable between the button and my computer.
In this video, I build a 3D Printed Desk lamp. The basic design came from Thingiverse, but I repurposed my LM2576 Constant-Current design to serve as a dimmer. It all started when I found an interesting lamp on thingiverse, which used 75mm air hose segments from another model to make a flexible articulating desk lamp. What appealed to me about this project is the size of it, and the use of COB LED panels, which I’ve been wanting to experiment with.
Every few years I revisit the idea of building an ECG machine. This time I was very impressed with how easy it is to achieve using the AD8232, a single-lead ECG front-end on a chip. The AD8232 is small (LFCSP package) but breakout boards are easy to obtain online.
5V powered 100LED circuit was consuming around ~1.8Watts(though 5.1Ohm series resistor was really hot) and the brightness of the LED’s were not bad, especially difference between first led and last led brightness didnt bother me it was hardly noticeable when seen from distance. So I decided to use them as a christmas decoration for my garden.
I wanted to use them with battery-bank as there was no power-outlet readily available(for the safety of my children, i would avoid any 230v circuit in my garden especially in wet weather). Also I wanted them to be switchable remotely to avoid going out in the freezing cold. Hence this is what i came up with.. an “ESP-12F based USB-5V switcher”
For years I’ve followed the “uRadMonitor”, a device that does air quality monitoring and radiation monitoring. I’ve played with geiger counter projects before and frankly found them to be not very interesting. However, the idea of monitoring air quality is something that seemed like it might yield interesting data. For example, as I’ve started to become involved in 3D printing, it would be useful to see whether or not 3D printing affected the air quality. It would also be useful to correlate my results with what my region reports for outdoor air quality.
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.
To expand my microcontroller and programming knowledge I have decided to try and make a Solar Powered Weather Station. My goal is to record parameters like:
*Air quality (something to do with CO or CO2)
I then hope to send (wirelessly) the data to a base station and log/display it on a simple website. To make things interesting I also aim to power the data gathering station from a large supercapacitor (~100F), and in keeping with my solar tradition the supercapacitor will be charged from a solar-cell.
In this project we build simple I2S stereo decoder with amplifier. To decode I2S data we use Princeton Technologies PT8211 16bit DAC. KA2206 audio power amplifier is used as driver stage of this system.
Structure of this I2S amplifier is self-explanatory from the schematic. We select PT8211 and KA2206 combination due to lower cost and availability. Unfortunately PT8211 DIP package is not available in local market and we use SO package in our prototype. We design PCB for the DIP packages, and therefore we solder PT8211 SO package to PCB using “SO8 to DIP8” converter.
As the name implies, a transmit converter takes another frequency – such as that produced by a conventional HF transceiver – and converts it to another frequency. In my case I use an FT-817 – a low-power (5 watt) all-mode, all-band transceiver that is a favorite for VHF, UHF and microwave enthusiasts that use transverters. Because of its small size, feature set and already-low output power, it is a natural to be used in this application.