The first step is to solder the kit together. If you've never soldered before, check the Preparation page for tutorials and more.
Next, get ready by placing the PCB in a vise so that you can easily place and solder the parts in!
Check also that you have all the tools you need, & warm up your soldering iron to 650-700degF.
Next, with your soldering iron, solder each of the resistor legs. Place the tip of the iron against both the pad (ring) and lead (leg) and after a few counts, touch the solder in, to make a nice joint.
Repeat for the other joint.
Next is the other 47 ohm resistor, R2
This one doesnt sit flat like R1, so bend it over as shown. Again it doesnt matter which end goes where since resistors work both ways.
Now that you have a lot of practice with resistors, you can do the remaining 5 all at once. Place R10 (10K pullup resistor), R3, R5 and R6 (1.5K resistors for the USB connection, LEDs and output buffer).
If you are using the UsbtinyISP with a SpokePOV kit, install R4 and R7 (1.5K) as well. If not you may want to switch these resistors for jumpers (see the second photo for a 'finished' shot) as it will mean that target boards with loaded pins can be programmed.
Note: sometimes the 74AHC125 is a bit larger than the silkscreen so you may want to put R7 in later, once the chip is in place.
Next are the two 3.6V zener diodes, D1 and D2.
These diodes help convert the voltage from the microcontroller down to 3.3V, safe for the USB connection.
Diodes, unlike resistors, have to be placed a certain way or they won't work at all. Each diode has a small black line at one end. Make sure that this end matches with the white line on the silkscreen image. (See left)
Tack two opposite corners of the socket, to keep it in place, and then solder all the pins.
No clipping is needed as the socket pins are quite short already.
Next to be placed is the 74AHC125 buffer. This chip does a level-shifting conversion on signals from the USBtiny microcontroller to the device being programmed. This way you can safely program chips that vary from 1.8V to 5.5V voltage.
Integrated circuits must be placed correctly, check that the notch in the end of the chip matches the notch in the silkscreen image.
When ICs come from the factory, the legs are angled out somewhat which makes it difficult to insert them into the PCB. Prepare them for soldering by gently bending the legs against a flat tabletop so that they are perfectly straight.
Next is the USB connector and the 12.00MHz ceramic oscillator. The USB connector is what we use to plug into the computer, the oscillator makes sure the USBtiny microcontroller runs at the precise rate necessary to communicate at the very picky USB protocol rates.
The oscillator can go in 'either way', they're made to be symmetric. The USB connector should snap in easily.
Next are the two indicator LEDs, green LED2 and red LED1. These LEDs let you know that the USB device connected successfully, and is in the process of programming the target device.
LEDs are diodes, and must be placed correctly or they wont light up, which is very confusing. Make sure the longer (positive) lead of the LED goes into the hole marked with a +. See the images to the left.
Next are the two capacitors, C1 and C2. These provide some power supply filtering so that the USBtinyISP is less flakey. C1 goes in the corner next to the USB connector. It is a non-polar ceramic capacitor so it can go in either way.
C2 is a polarized electrolytic. It must go in only one way. Make sure the longer leg of the capacitor goes into the hole with a +. Bend the capacitor so that it lies on top of the buffer chip.
Almost done! The last set of parts are the headers for the cables, and the jumper header. The 10-pin box header has a notch in it, make sure it matches up with the silkscreen, as shown.
The 6-pin header goes in with the long pins sticking up.
The 2 pin jumper has the long pins pointing out.
Finally, straighten the pins of the microcontroller and place it, so that the notch in the chip matches the notch in the socket (and the silkscreen) as shown.
Now go on to make the cables and put the PCB in the case.
There are two standards for AVR programming, 6-pin and the 10-pin headers. Therefore, it's important that an AVR programmer have both types of cables. The 10-pin cables are easy to come by, but the 6-pin ones must be custom made. However, making a cable is super easy, just follow these steps!
If you're using the adaptor for a spokepov or don't need the 6pin cable, you can just skip this part.
Do not use needlenose pliers to try to press the pieces together. You have to have very flat pressure from both sides.
For example, use the flat side of a tool to press against a table top.
Plug in the two cables as shown, the red stripes on top and so that the cables don't bend over the plug (the case wont fit).
Put the PCB into the bottom case half.
The 6-pin cable may have strain reliefs that can clip on. You don't really need them but if you do want strain relief, put it on the one that goes to the target: the cable won't fit in the case if the strain-relief bit is on.