This wrist watch, made by Elia, is a binary based wrist watch i.e. displays time in binary digits and is small in size. The yellow-color LED’s for the digits perfectly suits the watch and also is compatible with the OSHPark PCB, which is a custom PCB-board manufacturer. Another interesting fact about the watch is the strap which is paracord bracelet along with a buckle. The steps to make the buckle are easily available on the internet. The watch is powered by the PIC microcontroller which comes with a SSOP package.
Along with the PIC, it also has an on-board ‘real time clock’. Moreover, it also features a sleep mode in which there is no display and consumes only 150uW of power. There can be additional power saving by pulling the remaining pins to either VCC or GND. However this functionality is not yet available in the current PCB. Overall, the watch is really good and a must try for those people who have just started learning the PIC microcontroller. Moreover, if you are considering to make this watch yourself with the same schematics, I would advise you to cover the PCB and the LED’s with a good quality glass.
LEDs have an effectiveness higher than that of just about all the customary lights and hence are used almost everywhere. The system in the article is basically a driver that can control two groups of white LED’s. The LED’s are operated in PWM mode using a suitable timing to obtain the required colour. Moreover, the entire system can be operated wireless at a frequency of 433MHz using amplitude modulation. On the receiver die, it’s a powered by a PIC16F876A which act as a decoder for the received amplitude modulated signal.
The decoded signal is then processed by the controller to generate the required PWM signal for the two independent group of LED’s. The group of LED’s are driven by using a common source transistor and therefore the design is only compatible with common-anode LED strips. Another interesting thing about the procedure is the self-learning method it uses to learn the required codes to change the level of brightness for both the warm and cold type of LED”s used in the project. The entire schematics along with the code and the working are available on the website.
Beke Andras has an old monitor which needed some repair. So he decided to build a video generator for it. This monitor uses different signal than composite so he started investigating the problem. He took a dsPIC30F301 based board and started prototyping. Later this grew into PCB designed with Geda software.
Despite its different control, monitor still needed same horizontal, vertical and video signal. With a bit of code he was able to generate static images and moving characters (running horse). He used small special programs to draw static images and generate motion picture. Beke faced a small problem with horizontal size, and he hopes that someone with tube knowledge could help to solve this issue.
Programmable timers are used in many areas. You can set timer to turn on/off light after some time, turn off oven, control water sprinkler and do other time dependent switching. You can buy such timer for cheap – some of them even plugs in directly to AC outlet. But if you like to have things in control and be able to add additional features, then you can build a simple timer with small microcontroller. Hristo has built a programmable timer on PIC16F628A microcontroller. He intended this timer to be used in hos UV light exposure box. But by adding a relay, it can be used for anything.
Timer can be set and run with three switches where couple of them are for setting minutes and seconds. LCD indicates timer running state and is used to navigate menu while setting time. Timer also has a calibration jumper where timer can be adjusted to run more accurate. Once timer runs out timer turns switch off and then sounds buzzer alarm. Really simple and useful circuit.