You'll be the talk of the town when you wear this obnoxious, oversized, completely impractical wristwatch. Display your favourite foul language, song lyrics, prime numbers, etc.

Inspired by the Microreader kit, I decided to make a giant watch using similar sixteen segment displays. Twelve hours later, I came out of my masochistic fugue and stopped trying to route a sixteen bit data bus on a single sided pcb small enough to wear on your wrist.

Returning to my digikey box of mystery, I came up with a four character display made up of 5x7 led matrices. 7 bit parallel data input, no need for umpteen current limiting resistors, upper and lower case characters, the rest writes itself.

This instructable is not meant to be a tutorial on creating PCBs or programming PICs. In all fairness, I wouldn't actually recommend that anyone try to make one of these. If you know enough to follow along, you can probably do a better job than I did. If you don't know what's going on, then this instructable isn't going to teach you all you need to know.

P.S. If you use this to scroll internet catchphrases in public, you are a bad person and should be ashamed.

Step 1: Get your crap together

What you're going to need:

DLO3416 Intelligent display

Comes in red, green, lavender, fuchsia, and maple walnut flavours.

PIC 16F628A or 16F648A

You might be able to get away with another pin-compatible PIC, just make sure to read the datasheet carefully. Either way, you'll need at least one PIC in the SOIC package and probably a DIP for breadboarding the circuit. The 628A and 648A are identical except for the amount of program memory available (2k vs 4k). Use the 648A unless you have some 628As lying around.


This is a charge pump dc-dc converter. We're going to use this to make 5V for our display from a 3V coin cell battery. Get a few so that you can destroy at least one.

The passive components are all through hole type. I know the mishmash of surface mount and through hole is kind of aesthetically displeasing but what can you do.

-Capacitors: 10uF (2), 1uF (1)

-Resistors: 10K (1)

-Switch: N/O momentary pushbutton. The clicky kind you see everywhere cheap buttons are needed.

-Pin headers/sockets: Two pins and a jumper, and a single row of 6 sockets. You can substitute pins for the sockets if you enjoy accidentally tearing clothing and skin.

-CR2032 Coin cell and holder.

Supporting cast:

Soldering iron with the pointiest tip you can find. The MCP1253 comes in a surface mount package small enough to be accidentally inhaled.

Copper clad board, etchant, acetone etc for making the PCB.

PIC programmer with an ICSP header and cable.

Some other stuff without which you won't get very far but that I can't remember right now.

i wanna see the video... please upload it again ;)<br />
There's something wrong with your video, the embedded player says "no longer available" and copy/pasting the url fails too.
I can think of an interesting 4 letter word that you could have displayed... actually I can think of roughly 4
hello!<br/><br/>I first say this display in a micromouse Min4A<br/><a rel="nofollow" href="http://www.np.edu.sg/alpha/nbk/umouse/min4a.html">http://www.np.edu.sg/alpha/nbk/umouse/min4a.html</a><br/><br/>He use the <strong>SLR2016</strong>, it is much slimmer. It cost 20.78$ cdn <br/><a rel="nofollow" href="http://catalog.osram-os.com/media/_en/Graphics/00034123_0.pdf">http://catalog.osram-os.com/media/_en/Graphics/00034123_0.pdf</a><br/><br/>the DLO3416 is 19.63$<br/><br/>The only drawback of this display is that you need a lot of I/O on your micro.<br/>I think this is a great way to test your programming skill. You can code very crudelly or take the time to think and make something more effecient.<br/><br/>I would love and might give it a try! I got other projects to build and finish first ! :-)<br/><br/>Thanks!<br/><br/>Jerome<br/>
Hello<br/><br/>Do you use the chip enables (CE1, CE2, CE3, CE4)?<br/>I don't think you do. I was wondering what they do.<br/><br/>(D0-D6) is the desired data code and (A0, A1) digit address <br/><br/>How does A0 and A1 work?<br/><br/>Like this?<br/>0 0 = first digit<br/>0 1 = second digit<br/>1 0 = third digit<br/>1 1 = fouth digit<br/><br/>you select the digit and then write the ascii code on (D0-D6)<br/>that seem simple!<br/><br/>you add the PWM on pin 14 ( BL) to dim or blink<br/><br/>thank you!<br/><br/>Jerome<br/>
The chip enables allow you to use more than one display on the same data bus. I have them tied high/low as needed to enable the chip at all times. If you wanted to use two displays, you would add another address line and tie it to an active high enable on one chip and an active low on the other. You've got the A0 and A1 bits right, it is pretty simple. The only other function is the cursor, which I haven't bothered with.

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