How to connect the Digital8
Connect the first Digital8 to the master module
Use dupont-cables to connect the digital8 expander to the master module. The expander SPI pins on the master module may have different pinouts than the digital8. Different master modules may also have different pinouts. See the manual for the master module. Connect one cable at the time and make sure you connect it correctly.
Connect multiple Digital8 modules in a chain
The master module is the start. The master is the connected to the inputs of the first digital8 module. The outputs of the first digital8 module is the connected to the inputs of the second digital8 module, and so on. See the following figure.
Alternative ways for connection
If you want sturdier connections, then you can solder the Dupont-headers together.
If you have multiple expanders in a chain, you can instead use a little veroboard for the connections. Use 5 pole female headers and cut the copper between the legs of the headers. Then solder the female headers. Finally solder a 5pin male, angled pinstrip for the Dupont-cables at the left incoming side for the connections from the master module.
This figure is viewed from above. The green lines are the copper lanes on the bottom-side. Cut the copper-lanes under each female header. Use can use one 40 pin female header and cut it to smaller 5 pole headers. Create each 2×5 header from two 1×5 headers. Cut the copper before you solder!