5 digit Stop watch using 8051 and 16 X 1 / 8 X 1 LCD

When is your project assignment due?

Here is how you do it:

1) Connect LCD to 8051 2) Connect switches to 8051 3) Connect crystal to 8051 4) Write some software for 8051

Bingo, you have an 8051 stopwatch. Easy.

There is of course the option of finding the nerdyist looking kid in the class and simply paying him to do it for you.

Dave.

You missed:

5) Connect a 5V power supply to the 8051.

This was a major oversight on your part. Also we realy should give some hints about the software. You only really need two instructions the DJNZ and the MOV all the others although handy aren't truely needed for this sort of task.

devang wrote in news:1185883711.245820.269160 @z24g2000prh.googlegroups.com:

Get a serial or paralell LCD interface, unless you are using a version of the micro with an adequate built in raw LCD interface.

The software is easy, just timing loops timed from a 32768 hz watch oscillator, or better.

How hard is a 60KHz WWBV calibrator? ;-)

Cheers! Rich

^^^^ WWVB

WWVB in India?

Duh.

Never mind. (albeit WWV does transmit on 2.5, 5, 10, 15, and 20 MHz.)

Rich

Hey, give him a break. He's in Gujarat India, so all the nerdy kids are busy 24/7 working on firmware for foreign firms.

Best regards, Spehro Pefhany

--
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Can you rx that in india? I'd use a 1PPS from a GPS

Martin

Depending on how accurate you need the clock, you can take any 8051 and write a software timing loop. Like this: (Assuming 11.0592 MHz xtal and non-accelerated type 8051 or derivative.) Accuracy will depend on crystal, and your software. Also temperature, etc...

ONE_SEC: ;ONE SECOND DELAY - 925183 CLOCKS / 1.0038880 SEC.

MOV VAR3,#08D MOV VAR2,#08D MOV VAR1,#236D SECLOOP: DJNZ VAR1,SECLOOP DJNZ VAR2,SECLOOP DJNZ VAR3,SECLOOP RET

Next option: (Generally more accurate, with less to screw up.) Connect a real-time clock (such as the Dallas Semiconductor DS1307, or equiv). Use the RTC to keep track of the time, and the 8051 to handle the LCD.

Next option: (If money is no option) Use an "all-in-one", like the Dallas Semi DS87C530, which is an 8051 with a built in clock. But this only comes in weird packages and is rather expensive.

Also, in my experience, serial LCD's are more $$ than parallel. It is not difficult to code a parallel LCD, so save your money. You will almost certainly have enough port pins available to drive it.

Good luck.

-mpm

We can't give the OP all the info now can we? :->

Dave.