An LED Persistance of Vision Name Badge




Introduction: An LED Persistance of Vision Name Badge

About: I have a background in digital electronics, and am very interested in computers. I love things that blink, and am in awe of the physics associated with making blue LEDs.

This Instructable shows a name badge that I have built for my daughter.

I have seen the Defcon badges, and thought they were cool. Why cant my kids have one as well - but specially built for them?

So here you go - A simple badge that uses a PIC 16F88, and a handful of LEDs, and flashes your child's name in lights when they shake it, or push a button.

I have left space on the PCB that I designed so that it can support an accelerometer.  It isn't in this version because I have to order the parts.  This one is created using the bits I had in the garage!

Step 1: Etch Up a Board - Make It Decorative

The first step it to create the PCB using your favourite PCB package.

You could download my PCB file, but it probably wont work unless your child is named Sian!  Just in case people ask, I have included it as a PDF file.

In Sians case, I created a PCB layout - and made a decorative fill as a background - I think it turned out pretty well!

Here is a photo of Caties board having finished the etching process - I just have to clean the etch resist off the board, and mount the components.

Step 2: Mount the Components, and Program the Micro

Having made the PCB, you then get to mount the parts, and then program the microprocessor.

As with all of my projects, there is a programming header mounted on the PCB.  I simply connect my home made PIC programmer to it, and I can program the board.

If you want to make your own programmer, then I can heartily recommend the open source one at  I have built it, and it works beautifully.  Alternately, you can simply purchase one of the many programmers on eBay.  They also work fine!

Here is a copy of the hex file that says Sian, and the asm file. Also included is the schematic.

You will notice pads for an optional accelerometer and associated components. When these arrive, I will be able to add code to allow the display to always be the right way around irrespective of the direction the board is being shaken!

You will also notice a 5 pin header on the back of the board - that is for a programmer that I use for development.

Here is a detailed list of components that are used on the PCB

U1 - 16F88 Microprocessor
R1-R7 - 1k0
R8,R9 - 10k0
R10 - 10k0
C1 - 0.001uF
Sw1 - Pushbutton Switch
D1-D7 - SMD LED (Red)
D8 - 1N4004 Diode
J5 - 5 pin programming header
B1 - CR2032 Battery + Through Hole Holder

Optional accelerometer components
U2 - MMA7260Q Accelerometer
R11-R13 - 1k0
C2-C4 - 0.1uF
C5 - 10uF 16V

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    5 Discussions


    8 years ago on Introduction

    the most simple and serious i ever met .thanks


    10 years ago on Introduction

    Very cute, and a nice gift!

    This I'ble itself could use a bit of expansion to allow more novice users to successfully follow and reproduce it. 

    A components list (including values for resistors etc.) would be very helpful.  An annotated PCB layout, showing which components go where (and what orientation :-) could be beneficial.  Could you include a PDF version of the schematic, for people to print?

    It looks like you've got the JTAG(?) header mounted on the back side of the board, is that right?  Is there anything else we need to know about on that side?  A picture might be useful.


    Reply 10 years ago on Introduction

    Thanks for the feedback - I thought that I added an annotated PCB layout - but in reflection that could be clearer.

    I'll make the changes and make it better :-)


    Reply 10 years ago on Introduction

    Read picture added, as well as a clear component overlay and detailed parts list - Thanks for the help!

    The 5 way header is also for a programmer that I use - thats documented in the instructable now.