1- what you will need If you feel geeky enough to build SPIN yourself, you might find this tutorial as a good reference. If you've never soldered before this one might encourage you to try.

At first you should gather what you'll need, that is:

• 2 SPIN printed circuit boards (PCBs) which differ slightly (one has a track cut off, and wire jumper)
• 128 LEDs
• 8x33ohm resistors networks (16)
• 74HC595 buffers serial-in shift registers with output latches (8)
• AA battery clips (two for each battery, 4 total)
• crystal oscillator (6.144MHz)
• IDC10 sockets (2 of them to connect boards, 1 to program microcontroller)
• ATmega32 microcontroller (SPIN needs only one heart)
• MAX3221 driver in SOP16 package
• Hall effect sensor (eg. A3214EUA, important parameter is power supply, which should let you run it at less than 3V)
• capacitors (4x 100n and 2x 33pF), preferably in SMD package
• tweezers might be handy

2- mcu orientation (notice dot marker)Soldering integrated circuits
There are four kinds of integrated circuits used in SPIN project, which are: mcu, buffers, RS232 driver and hall sensor. There are two ways of placing buffers and driver on board's pads, and four ways you can put AVR on it, so be careful. Package of each circuit is different, but there is one rule that applies to soldering each of them. To solder these in correct orientation you'll have to find a marker on a circuit (printed line or dot, a notch etc.) and match it with a marker on PCB (usually a dot) - notice the picture on the left. Soldering AVR and RS232 driver will be the hardest part, so you might want to start with soldering these to be through with it, or skip this point and do the warm-up on something easier.

3- max3221 and capacitors (communication with PC)RS232 driver (used to talk with PC)
This part includes soldering five elements of two types, which are four capacitors and RS232 driver, which is used to convert AVR voltages to suitable level allowing it to communicate with PC. Soldering capacitors (needed by the driver to collect charge) might look hard, but actually it's much easier than it looks. However, attempting to stitch them without tweezers might be a bit challenging. While soldering driver- mind correct orientation of the circuit- if not sure use the picture on the right and everything will be clear.

4- oscillatror and 33pF capacitorsCrystal oscillator and capacitors
If you're wondering now why did not we start with soldering these parts firstly, as they are perfectly easy to solder even for a newbie, here is an answer: doing so would make it hard (if not completely impossible) to access some of the AVR's pins. This would be a mess, so if you decide to change order of soldering- feel free to do so, but make sure you're aware of consequences. C1 and C2 where meant to be through-hole components (not SMD's), so pads for these were designed as holes, not rectangular pads as for C3-C6, but it really does not make a difference. Actually SMD components are smaller and it might be harder to accidentally break them out of PCB, as they do not stick out. Depending on type of type of capacitor you might have to bend back it's terminals (on picture 4 you can see a crystal with only one terminal bent).

5- LEDs terminals used as jumpers6- jumpers from bent LEDs' teminalsBuffers and jumpers
Soldering 74HC595 now should be a piece of cake (remember about correct orientation). There is 4 of these on each board, so it's gonna take a while.
As you can see on the picture number 5, there are also some jumpers you'll need to install. Don't ask why I put all these colours there. Ok. If you want to know these where to emphasise, that jumpers should NOT be installed in same holes on both PCBs. Green marker selects whether to use 2 or 3 boards connected together (notice however, that 3 boards configuration won't work), and yellow and red jumpers are used to... never mind. Just put it as depicted on the right ;] On the left picture (number 6) you can see the magical process of bent LEDs' terminals into amazing jumpers. When cutting off some of LEDs' terminals remember, that you'll still need to use these diodes, so try not to shorten it's terminals too much.

7- resistors networks (laid as flat as possible, to prevent accidental damaging)Resistors
As you probably know, resistors usually have only two teminals, and ones that you have in front of you have nine of these. How is that? It's because these are not casual resistors, but resistors networks, mening that there are few resistorc connected together, and enclosed in single package. To be more precise - there are eight resistors there, sharing one common terminal, and having one on it's own. That's why there are 8(private) + 1(public) terminals in one package. As you can see on the left, there is a dot symbol on each network - it marks "public" terminal. Make sure, that this dot goes near the dot on the board (not the other way). It's again all about correct orientation ;]
During this phase only one simple rule apply - lay these as flat as you can (check picture 7), as this will make SPIN more robust and reliable.

8- LEDs (longer to rectangle, shorter to oval)
Final step is 128 LEDs. Its boring, but easy. You can't do it wrong if you remember about correct polarity (longer terminal to rectangular pad, shorter one to oval pad). There is, however, one pitfall - eight LEDs on each board are put the other way around, meaning, that you'll have to carefully install LEDs in pads' holes- just mind the orientation once again.