Start by plugging the 2x20 header into a Raspberry Pi, this will keep the header stable while you solder. Make sure the Pi is powered off!

Place the HAT on top so that the short pins of the 2x20 header line up with the pads on the HAT

And Solder!

Heat up your iron and solder in one header connection on the right.

Once it is soldered, put down the solder and reheat the solder point with your iron while straightening the HAT so it isn't leaning down

(For tips on soldering, be sure to check out our Guide to Excellent Soldering).

Solder one point on the opposite side of the connector

Solder each of the connections for the top row

Flip the board around and solder all the connections for the other half of the 2x20 header

Check over your work so far, make sure each solder point is shiny, and isn't bridged or dull or cracked

Place the 2 pin terminal block first, make sure the two 'mouths' are facing outwards

Use some tape to stick the terminal down in place

Flip the board over, the tape should keep the terminal block in place

Solder the two big connections, use plenty of solder!

Check your work, the connections should be solid and shiny

Next up we will attach the 2x8 IDC header. Unlike the 2x20 header, this connector has a direction!

Notice in the middle there's an outline for the connector in the middle. On the right it says HUB75 and on the left of the connector there is a little 'cutout' shape. This cutout shape must match up with the cut out on the connector.

If you solder it in backwards, its not a huge deal, you can use diagonal cutters to cut out a notch on the opposite side, but if you get it right then you will never have to worry about plugging in your matrix data cable the wrong way

Place the connector in the slot so that the notched side is on the left

Use some tape to hold the IDC connector in place

Flip the board over, the tape should keep the connector from falling out

Solder in all the pins like you did with the 2x20 connector

Check your work! Make sure all the solder points are clean and not shorted or cracked or dull

Flip the board around & solder up the other half!

Check your work one last time...now continue to testing!

Look for the Address E pads located between the HUB75 connector and Pi camera cutout.

Melt a blob of solder between the center “E” pad and the “8” pad just above it (for 64x64 matrices in the Adafruit shop)…or the “16” pad below (rare, for some third-party 64x64 matrices…check datasheet).