This is an inexpensive Persistence of Vision (POV) toy, which is designed for beginners in electronics. You swing this little thing around to reveal a customizable message or image through it's 8 red LEDs. It has 4 holes for mounting on bikes, fans, and anything else that swings around. You can purchase this kit from the Make Store.
This project is the third revision of the MiniPOV. This version is nearly identical to the last version, MiniPOV2 but uses the serial port (possibly with a USB/Serial converter) instead of a parallel port, for programming. Because the programmer is built into the kit, one does not need a special "microcontroller programmer". This version can be used with PCs (Linux/Unix or Windows) and Macs (running MacOS X and with a USB/serial converter).
This kit is great for soldering beginners. To learn the basics of soldering check out this great guide by noahw. Also, here's a good video tutorial from the MAKE blog.
Step 1: What You Get and What You Need.
This kit is great because it's mostly self contained. The only thing you really need is two AA batteries and time. It's also easier if your computer has a serial port; it looks like the monitor output but inverted.
A note on the resistors: electrical components are marked by colors, and you'll be getting all sorts of things that look the same. Be careful not to mix them up!
What you get:
1 ATtiny2313 Microcontroller - IC
1 20 Pin Socket for microcontroller - IC1
3 1/4W 5% 4.7K resistors - R10-R12 (Red band)
8 1/4W 5% 47 ohm resistors - R1-9 (Brown band)
3 5.1V Zener Diode - D1-D3 (Red body)
1 Battery case with screw - U1
8 Red LED - D1-8
1 DB-9 female connector w/solder cup
1 Sticky pad
What components you'll need:
2 AA batteries
(if you don't have a serial port) USB to serial converter
The ones with the PL-2303 chipset work:
Here or here or somewhere else
What tools you'll need.
Rosin core, 60/40 solder
Soldering Iron hopefully with a pencil-like tip
A vice to hold up the PCB
(You can get all this stuff really cheap at http://www.all-spec.com/ or http://www.allelectronics.com/)
Step 2: Resistance Isn't Futile!
Lets first populate the PCB with resistors and diodes-- you know, to keep those LED's in line!
An organized approach will ensure no mix-ups. Here's the order to attach components:
R10-12 (Red Band)
R1-9 (Brown Band)
D1-3 (Red Body)
Before I hand it off to the images, here's the basic idea:
You put the component in the PCB in on the side with writing, bend the tails a little, turn the board over and solder them into place. Then cut the excess tails off at the start. Follow the images, and look at the comments.
Note that the D1-3 diodes need to placed in a specific orientation. Align the band on the PCB to the band on the diode. (Check out pictures for illustration).
Step 3: Serial Port.
This step is short because the LED's deserve extra attention.
Stick the serial port to match the terminals on the board. When soldering make sure you get some solder underneath the soldering cups as well as in it. Don't forget to solder both sides down.
There's a close up of the finished serial port in the next step, as well.
Step 4: LEDs
This part may is a little tricky so be cautious.
LEDs have a positive and negative end. The easiest way to tell them apart is by the longer end, which is positive. On the PCB, the negative end is closer to the edge.
Insert all the LEDs into the LED spots with the shorter tail close to the edge. Follow the usual procedure of bending the tails a little bit before soldering, solder, and then clip off the tails. Don't worry if any LED is not perfectly straight; it won't be noticeable.
Step 5: IC U R OK
There's a little "U" shaped gap on the IC socket as well as the PCB board. Line up the IC socket to the PCB. (Remember you're going to solder the IC socket not the actual IC to the board).
This is also a little annoying- you may need to hold the socket into place with your finger as you solder at least one end in. It may be easier to just put the entire board on the end of your table for the first few soldering points. After that you can move the board back to your vice since the socket will not fall out.
Solder everything, and then stick the IC on top. Remember to also line up the IC (has the "U" drown on it) with the socket. There's a dark circle on the IC, which should be facing the serial port when oriented properly.
Step 6: POWER
Solder the battery wires into place. Attach the wires so they're over the top of the PCB. (See pictures).
The RED wire is +
The BLACK wire is -
You may want to snip the tails a little bit.
Step 7: IC U R OK 2 C.
Now that construction is complete put your AA batteries into the case, and switch them on. The KIT will have a pre-programmed message.
The MiniPOV needs to have the serial port facing up, and you swing it to from right to left so someone can read the message. Being in a shady room helps. You can experiment with something reflective like a turned off tv. (Then you'll need to swing it from left to right to read it yourself).
Step 8: Customizing.
There's a good list of instructions at the official site and more specially about customizing here. It's easiest and quickest to do in Windows, but there is software for OS X and Linux as well. Check out the links above for details. An overview follows:
-- You get the latest WinAVR. Install it.
-- Get the latest MiniPOV source. Extract it somewhere like C:\minipov.
-- Use Tool 1 or Tool 2 to generate a custom message, and save the file as mypov.c in the directory you extracted Minipov.zip.
-- Plug the MiniPOV into your PC's serial port and turn the MiniPOV on (lights stay off)
-- Start/Run, "cmd," cd c:\minipov, "make program-mypov"
These are overly simplified. Again check out the links for more detailed instructions (no sense in copying everything here).