Simple PIC based timer with LCD

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. Continue reading

PIC16F628A timer for UV exposure box

Using UV exposure technology is common way of building PCB at home. If you tried this, you probably know that exposure timing is very important to get precise image on photoresist. Overexposure or underexposure always lead to failure. So it is best to leave timing for timer. If you built your own UV box, then you should also build a timer. Diyfan suggests simple PIC16F628A based timer project. It is really simple – 2×16 LCD displays time and status. Three push buttons allows to select time, start timer and stop timer. It also has speaker to play sound alarm when time runs out. Circuit simply send signal to a pin which can be connected to relay of your choice which then controls the lamps. Of course it can be used for other purposes including motor drive for some time, water sprinkler and other. Continue reading

A programmable timer using PIC16F628A

People are just too lazy – that’s why the remote control was invented anyway. Some aren’t lazy at all yet they still have unnecessary power consumptions due to the fact that they forget turning things off. To alleviate the problems concerning timed functions the timer was invented – obviously the name tells the story. A very useful piece of work, yet not all appliances have a timer built into them. This particular project is a simple yet elegant way to cut unnecessary power expenses by turning things on and off for a specific span of time. It harnesses the power of PIC16F628A to control a single pole double throw relay that is capable of operating at AC line voltages while keeping time at the same time. The timer comes with an LCD to indicate the amount of time left before the relay changes state; it also has buttons to be able to adjust the time. Continue reading

PIC based dual light timer controlled switch

This project speaks for itself – it serves as simple dual lamp switch with delay timers. Project is really easy to build as it uses few components. Each lamp is controlled by button. When one of the buttons is pressed – lamp is turned on via relay. After predefined time lamp turns off. This might be convenient where lamp is needed for short time, for instance while you go upstairs, or just when you entering the house and need light to find a regular lamp switch. Project files including source code and PCB files are available for download. Continue reading