Tag Archives: Electronics

PS/2 keyboard filter (interceptor) on Microchip PIC

In the project of “internet vending machine” we used almost standard qwerty keyboard and standard PC, so we needed to have possibility to be able to switch off keyboard during reboot, to disable CTRL+ALT+DEL and so on. These functions with a decent quality, until the death of the project, had been performing by “the keyboard interceptor” device. Interceptor is a device that is connected between PC and keyboard for keyboard data filtering. Device also capable to receive from external sensors and transmit to PC via serial port some data, to control some peripheral devices , but it’s main task, which consumes the most of it’s resources, is keyboard data filtering.

Presence detector on Microchip PIC and TSOP1833

Some years ago I participated in a startup that was aimed to create some sort of vending machine. Those machines had to sell internet access for people in places like airports, railroad stations and malls. At that time (2005-2006) smartphones had just started to become popular and access to the Internet wasn’t so easy as […]

Final version of the LED message board.

This is the last chapter about led message boards. The highest point of their evolution (I mean, this particular kind, of course 🙂 ), guided by me 🙂 At the end we concluded that the most usable size for our message boards is 7x64px. We had been experimenting with different matrix sizes and different LED […]

Hard way to electronics.

This is a preface to the next few posts about simple LED message boards. Since I was a child I was interested in electronics. But it was just a feeling, impression. There were no any actual deeds until, probably, my 15th birthday. Why hadn’t I done anything to get closer to my field of interest […]