Tuesday, June 23, 2020
Build a wireless energy POV display propeller clock with Android app
Thursday, January 23, 2020
How to make a double sided ultraviolet exposure box for making PCB
I had a broken Samsung MM-N6 audio system and so I've decided to build myself a double sided UV exposure box using it's front panel since it already had an LCD display, buttons and a sliding motorized panel. The sliding panel can be replaced with a door.
Here is an overview video with the version 1 of the box. This article presents an improved version of this box.
Saturday, September 7, 2019
Setting preferred units in Eagle CAD to metric or imperial
SET Interface.PreferredUnit nwhere n can be:
0 - the default value. Eagle decides if will display metric or imperial
1 - imperial
2 - metric
To change current units in Eagle CAD, simply paste the command in the command line, replace the n with your preferred value and press enter. To confirm that it worked, open the DRC window.
Imperial units in Eagle CAD DRC window |
Metric units in Eagle CAD DRC window |
Monday, August 19, 2019
How to build a zener and LED diode tester using a 555 timer DIY
If you have a bunch of salvaged Zener diodes you need a quick way to sort them. In this article I describe how to build a simple test equipment that can be used to measure the breakdown voltage of a Zener diode. It can also be used to test LEDs and their color, since sometime a color LED can look white when not lit. This Zener tester is powered from a 9V battery so it doesn't involve dangerous mains voltage and can measure diodes up to 90V with the help of a 555 timer boost converter.
I also use it for checking for burned LEDs in a mains light bulb.
Thursday, June 27, 2019
How water flows inside a washing machine
Monday, December 31, 2018
ESP8266 library for EFM8 microcontrollers - Server mode
Of course this is not a real web server although with an SD card whole HTML pages could be served. The purpose of this library is to extract queries from a URL requested by a client. This way for example you could change color and brightness of an RGB led using a color wheel in a phone app or control home appliances from anywhere in the world.