The easiest way to get a Time Machine working is to use the custom printed circuit board, along with the components in this page.
To obtain a Time Machine Board, buy one here.
You will only need one of these, but this is for a set of 20! Antrader 20pcs Dual Female Pin Header Socket Connector Strip. Another connector which should work is available here.
IMPORTANT NOTE: The 40-pin connector is soldered onto the BACK of the board. All other components are soldered onto the front. If you accidentally solder the connector to the front (as I have done, by mistake), it's basically impossible to fix.
Micro SD card
16 GB is more than sufficient. 8 GB will work also. These are generally available, and you may already have one, but you can get one (or more) at Amazon:
Click here and download the SD card image to your computer. Then "flash" the image to your SD card using a program such as Balena Etcher or the Raspberry Pi Imager (For this method, choose the "custom OS" option, then select the image file that you downloaded).
Rotary Encoder Code Switch Digital Potentiometer with Push Button. These cost about $12 for 10 knobs. You only need 3, and you can find similar ones in smaller batches. Just make sure they have 5 pins and 2 mechanical mounting points. Available at Amazon https://www.amazon.com/gp/product/B08BFJ4F5C
The time machine uses a 128 x 160 pixel display. There are many similar/equivalent displays which work with the same driver, but have different pinouts. If you are using the Time Machine Printed Circuit Board, then make sure to get this one, which has 8 pins as shown.
The screens are also available on Amazon (https://www.amazon.com/gp/product/B07BFV69DZ) for $15/screen. It's expensive, but sometimes it's the only thing in stock.
There are two different button sizes on the Time Machine. You will need 4 of the 6mm buttons, and 2 of the 12mm buttons.
There are several varieties of each, but these are some typical examples:
12 mm (you need 2 per Time Machine)
6 mm (you need 4 per Time Machine)
https://www.amazon.com/gp/product/B07VSNN9S2 (package of 120 pieces!) or https://www.amazon.com/Momentary-Tactile-Button-Switch-black/dp/B0796Q3PRB (pack of 100 pieces! -- also taller buttons, which you may prefer).
A variety pack (included various lengths of both 6mm and 12mm buttons)
I recently bought a variety pack of both 6 and 12 mm buttons of various lengths (https://www.amazon.com/Hilitchi-250-Pcs-Tactile-Momentary-Assortment/dp/B0722LBKV7), which is surely overkill, but will give you a lot of flexibility.
Screws, nuts, standoffs
The screw size for the raspberry pi and the accessories is M 2.5
This set of nylon screws, nuts, and standoffs is what I use.
LED and Resistor (for v2.1 boards)
The power indicator LED and resistor are completely optional. The Time Machine will function perfectly fine with our without them. If you do not want the LED (say, you are installing the device in a bedroom, and don't want the light) you may simply leave these parts off.
Note: the resistor goes on the back of the board, where it will not interfere with the case, and the LED's short pin goes through the square hole.
You will also need:
A micro USB power cable for a Raspberry Pi 3, or a USB C power cable for a Raspberry Pi 4. This plugs into the Raspberry Pi. I think nearly everyone must have one of these at home, but if not they are available here or here.
A cable to plug the Time Machine into your stereo. The Raspberry Pi 3A+ has a 3.5 mm (1/8") headphone jack. You could listen to it on headphones, but you can already do that on your phone. I use a cable like this to connect the Time Machine to my stereo. Or you could use an RCA adapter to give the Time Machine an RCA port. The Raspberry Pi can also send digital audio through the HDMI output, instead of using the 3.5 mm headphone jack. For this, you will need either a micro HDMI cable (for Raspberry Pi 4) or an ordinary HDMI cable (for Raspberry Pi 3A+) NOTE: To use the HDMI audio, you must plug in the HDMI cable while the Time Machine is powered down, or reboot after plugging it in. When the Time Machine is powered up with HDMI connected, the Time Machine will send the audio to the HDMI.
Tips for Assembly
Start by soldering the screen to the board. Solder one pin and make sure that the screen is flat against the board. Adjust if necessary by re-heating that pin and moving the screen/board. Once it's flat, solder the remaining pins.
Solder the buttons. These are easy.
Flip the board over and solder the connector onto the BACK of the board. Again, solder one pin, make sure the connector is flat against the board (it always is, but it's good to check), and continue.
Place the knobs on the board and solder one of the pins of each knob from the FRONT side. This requires the soldering iron to be used at a sharp angle, but it is the best way to ensure that the knob stays in position. You can reheat the pin and adjust if the knob looks off-kilter. Then flip the board and solder all of the pins on the knobs on the back side.
The power and ground are clearly labelled, but these are the mappings that I beeped out for the other pins.
8 (screen CS)
10 (MOSI screen SDA)
25 (screen reset)
24 (screen A0)
15 (UART RX)
14 (UART TX)