On-Off control by pic lcd and relay

I am doing a project which has automatic on- off system for a bulb of 60watts

using atmel 89c51 .. The main thing is to switch on and off the bulb for the time set by user. The time setting is made using two switches that interacting with lcd(16 cross 2).

I have one idea that to set time, programming is enough and switch control to the bulb is done with the help of a relay. Is it work without any problem or easy way to construct this project?

Read the input from the user.
Turn on the light.
Delay the MCU for the time that was inputted.
Turn off the light.

It's a relatively easy project.

Time as in hour of the day time? Or for instance 40 minutes. Or both?

P.S. Not to be anal, but why did you say PIC if your using Atmel?

If you are using a micro, for a simple improvement to the circuit that will add a whole ton of functionality, use a Real Time Clock (RTC). Many of them have an I2C interface, but you can get some with an SPI interfaces that are easier to program.

The RTC will give you time (hours, mins, secs), day, date, year.

Pump it out to an LCD interface and you have a clock.

(have a look on my website to see how it is done)

Remember to put a diode across the relay coil to stop the back emf.

Good luck

colin mac said:

Read the input from the user.
Turn on the light.
Delay the MCU for the time that was inputted.
Turn off the light.

It's a relatively easy project.

Click to expand...

thanks for the suggestions! Here i specifically using atmel series that's why i am not named as PIC . Here after i should use it.

I know little about interfacing cards. Is there any easy way to learn about the cards with their related applications?

What type of switches may i use here to alter the timing that is easy to all user?

mic5 said:

What type of switches may i use here to alter the timing that is easy to all user?

Click to expand...

A keypad.
**broken link removed**