Electel Blogspot

This is a wrap-up article for interfacing hardware with 8051 microcontroller. It's a combo deal for starters because this time, I have interfaced switches , LEDs , seven-segment-displa y and keypad all at the same time. I have already talked about them, individually, in my previous articles but for better understanding I think it's important to know how they work together. It will also give you some idea about dividing your code into segments and pieces which ultimately polishes your code writing skills. READ MORE

While I was home this winter, I saw that the remote for our TV tuner was damaged physically, causing the buttons to not function responsively. Some of them just didn't work. I saw this as an opportunity for a fun couple days' project to build a new remote controller for the tuner. The TV tuner was manufactured by a brand name RealView and, as expected, I couldn't find much detail about it. Thus, I had to reverse engineer the remote. From my previous experience in working with IR remotes, I had a hunch that the IR was most likely modulated at ~38kHz or ~56kHz. For those of you who don't know how this works, I highly recommend going through this website: http://www.sbprojects.com/knowledge/ir/ Thus, I connected a 38kHz IR receiver I had at home (TSOP1738) to an oscilloscope in order to figure out what IR protocol is used by the remote. Upon pressing the 4 key on the remote, I saw the following waveform: Fig. 1: Oscilloscope waveform capture of the received IR signal Note...

When we talk about input to the microcontroller unit, which may or may not be user input, it's not just ON/OFF switches or Push Buttons. In fact there are different methods for collecting data either from a user or the environment. According to the requirements, you can expect a user to press some button, toggle a switch , enter a username/password e.t.c. while various types of sensing devices are used to detect changes in the environment which will be discussed in my future posts. Today I am going to briefly introduce you to Keypad interface with the 8051 microcontroller. I have noticed many students having problem with this so I have tried my best to keep it as simple as possible while you will try your best to concentrate and understand it once and for all. READ MORE