Insert the two breakbeam sensors into their slots at the top of the 3D printed lid.

Strip and tin the breakbeam sensors' ground and power connections. Solder their ground connections together. Then, solder their power connections together.

The JST 3-pin socket cable will plug into the servo motor. Solder the cable's ground connection to an additional wire. 

Then, solder the breakbeam's shared ground connections to this ground junction. Cover the connection with heat shrink.

Solder an additional wire to the breakbeam sensors' power wires. Cover the connection with heat shrink.

Solder the following connections to the MatrixPortal M4's pins.

• The group's ground connection to the MatrixPortal M4's ground pin
• The breakbeam sensors' power connection to the MatrixPortal M4's 3V pin
• The breakbeam sensors' data pin to A1
• The JST socket's data pin to A4

Cut a JST 3-pin cable in half. Then, strip and tin its wires.

Solder wires to each JST end to create a longer cable. Cover all connections with heat shrink. This cable will be used for the STEMMA speaker.