Manual STORES Christmas Tree

The standard kit consists of:
 1x Christmas Tree PCB
50x WS2812B LED
16x 100nF (or larger) 0805 SMD capacitor
 1x Mini-USB female connector
 1x ATtiny402 microcontroller

Follow the following instructions to assemble your Christmas tree
- Solder the 50 LEDs. They have one marked corner. If you view the PCB with the text on the bottom of the LED footprint, this corner should be on the top left. It does NOT matter if this means the text is upside down; note that not all LEDs are mounted in the same orientation!
- Solder the 16 capacitors. They do not have a polarity, so they can be mounted in both orientations.
- Solder the microcontroller. Pin 1 is marked with a dot, and the pin 1 side of the microcontroller is chamfered. If you view the PCB with the text above the microcontroller, pin 1 is at the top left.
- Solder the USB connector. It only fits in one way.
- Continue with the optional parts and / or test the half with the USB-connector to see if it works. Then, connect the two PCBs with just three little blobs of solder in just one corner (one blob for each metal plane) and test it. If all is well, you may add more solder (also in the other corners) for mechanical stability, but this is not required.

If you would like to do some programming, you may consider buying to optional parts:
1x Tactile switch

And, if you would also like to implement USB functionality:
1x 1k5 SMD resistor
2x 51E or 68E SMD resistor
2x 3v6 zener (through hole)

To create a programmer, you also need:
1x 1k5 resistor (through-hole)
1x Mini-USB male connector (you cannot use a pre-made cable, since you need to connect to the OTG (fifth) pin of the connector, but since the programming interface uses just a single wire and 5V power, you might also solder this wire to the microcontroller directly)
1x Arduino (Uno tested; Nano probably works; others unknown)
 Optionally, some heat shrink and male NSR wires to cut up and connect everything in a nice way.

If you bought the optional parts:
- Solder the switch. It only fits in one way. (You could solder it on the wrong side of the PCB; this would work fine.)
- Solder the zener diodes. The ring on the package corresponds to the marking on the PCB. 
- Solder the 1.5k resistor. This is R3 on the PCB. You have only one 1.5k resistor.
- Solder the 51E resistors. These are next to eachother, close to R3. You have two of these.

For programming, have a look at these Git repositories:
https://github.com/SpenceKonde/megaTinyCore (Includes tinyNeoPixel examples, which you can use.)
https://github.com/ElTangas/jtag2updi (To use your Arduino Uno or Nano as a programmer; the UPDI pin of the microcontroller is connected to the OTG pin of the mini USB connector.)
https://github.com/12oclocker/V-USB_TinyAvr (V-USB firmware only USB implementation, ported to this series of microcontrollers a while ago; was not ported yet in 2019, so if you would like to implement USB, it is easier now!)

For reference, you can download the current firmware at:
https://docs.scintilla.utwente.nl/stores/strandtest_v3.ino (This is simply a tinyNeoPixel example, but set to 50 LEDs, a custom brightness setting, and a nice selection of effects that actually fits in the ATtiny402 flash.)