Multimeter Clock

The Multimeter Clock consists of three multimeters, the first meter displays hours, the second displays minutes and the last displays seconds. A 16F628A PIC microcontroller keeps track of time and outputs a calculated current to each meter to display the current time.

Get your own Multimeter Clock Kit here.
See Multimeter Clock project page here.

Step 1: How it Works

The user enters the time by pressing three time adjust buttons. The first button increments the hours, the second button increments the minutes and the third button resets the seconds. Once the time has been entered the microcontroller will keep track of time from there. An interrupt fires every 10th of a second to increment a 10th second counter. Another routine checks to see if we have at least one full second of time, if we do the current time is incremented by a second.

The microcontroller has a separate output for each of the three meters. The meters are all in 0.5 DCmA mode, the negative lead of each meter is grounded and the positive leads are connected to a microcontroller output via a current limiting resistor. The resistor in this case is a 4.7K however this can be adjusted depending on the meter current scale available. Keep in mind that the PIC can deliver a maximum of 25mA to each meter so a meter with a lowest setting above 25mA would not work without additional circuitry.

Comments

[mikerosati]

Great idea - I'm going to give this one a go as well..
I second in asking what software was used to draw up the schematic..

[taylorglenn]

What software did you use to draw this schematic?

[ynze]

Owww, wonderful idea, great build! Thumbs up!

[WhiteTech]

Hey, Excuse the noobish question, but your setting is .5 mA, so the max, when it's set on it, is .5 mA showing on the scale?

I have access to ammeters that have a non-changible scale that goes to 20 mA, can the kit run this?

[Toastalicious]

Why does the first meter say sunMa while the others are sunWa?

[Wroger-Wroger]

What? You have never made a mistake either?

[abbtech]

LOL, I never noticed that before. I am thinking that the 2nd and 3rd are SunMa knockoffs. :)

[abbtech]

LOL. I never noticed that before! That represents the quality of these meters I got, I should have spent more money on them. :)

[Kasm279]

I have one just like it except the colors around the dial are white, green, and red. Also, mine says MODEL instead of Sun(W/M)A, but it does say "YX-1000A" on it...

[signalelektronik]

What a great idee!

[abbtech]

Thanks

[Dr.Bill]

this is too cool

[cdousley]

LOVE IT!

[abbtech]

Thanks for the comment. Glad you liked it.

[canida]

Nice project! Excellent work.

[abbtech]

Thanks. :)

[twocvbloke]

That's a pretty cool device, I'm sure the steampunk sorts would love to make a version of it somehow, but as it is, I like it... :)