Assembly

Required tools

• Soldering iron, preferably one with interchangable tips. I recommend using a small conical tip for most work + a slightly larger bevel/chisel tip for SMD drag-soldering.
• Solder. Obviously. Solder containing lead is easier to use, though maybe not as healthy as lead-free.
• Flux. Either liquid, thick, pasty, pen-fed, whatever. Lots of flux equals good soldering. No flux means pain.
• IPA (isopropyl alcohol) and some lint-free paper towels + a toothbrush, to clean up any flux residue the board after you're done soldering.
• Solder wick, unless you're a soldering god and never make mistakes.
• Digital multimeter, for checking connections.

Recommended tools

• Hot air rework station. Makes soldering certain SMD components easier.
• Oscilloscope, for troubleshooting signals.

Buying decisions

There are basically three ways of getting your TinyLlama up and running:

1. Buy a complete, assembled and tested system.
   Unfortunately, this will probably be too time-consuming for me to do - and I'd have to charge a prohibitively high price to make it worth my while. This is a hobby project, after all.
2. Buy a parts kit with the PCB (with some of the smaller SMD components already soldered by the PCB manufacturer) and all of the PCB components. This is something I'm considering doing, at least for a small batch. Note that this will not include the system-on-module with its 2x32pin connectors, VGA card or Raspberry Pi Zero 2 W - you'd have to order those separately as seen in the BOM.
   Keep an eye on the Vogons thread for updates on kit availability.
3. Get the PCB manufactured yourself using the gerber files included in the kicad/Fabrication folder. I recommend JLCPCB. Parts can be ordered as you like. To keep the cost down and avoid having to modify the KiCad design/layout, I suggest using LCSC for most of the components, as that's what I'm using myself (BOM).

Assembly

Start by cleaning the TinyLlama PCB properly with IPA.

Solder all components onto the board. As always, it's easier to start with the low-profile ones first, like resistors and capacitors. If you do the large, tall components first, it can be hard to reach the smaller ones, or get a good angle on the soldering iron. If you're willing to spend slightly more, I recommended you let the PCB manufacturer pre-assemble most of the common components for you. Plus, some of the SMD components can be fairly tricky to solder without solderpaste and a heat gun (or even better, a reflow oven).
Tip: JLCPCB offers assembly and lets you pick components from the LCSC parts library.

Most of the components should be fairly easy to solder with a good soldering iron, lots of flux and good eyesight or a magnifying lens. The CS4237B TQFP-100 package can be tricky, though. I recommend lining the IC up perfectly, tacking two pins on opposite corners of the package in place, and then carefully and with a small amount of solder on a beveled/chiseled tip drag-soldering each side. Triple-check that none of the pins are shorted by excess solder. Shining a bright light from behind the board makes it easier to detect bridges. Remove any bridges carefully with a solder wick and tack the pins you touched with the wick again with a small conical tip. Remember, you can never use too much flux!
If you haven't used the drag-solering technique before, look at a few YouTube videos first.