...
- Cut the hdmi cable to the desired length
- Do the same for the BNC cable
- Find a ground/shield cable on the HDMI cable by plugging it into the analog in plug on the acquisition board (next to the row of jumpers) and testing for continuity to a ground pin on the board. The ground pins on the fan connector on the right edge of the board are convenient for this use.
- De-insulate the ground wire and mark it for later
- Find the signal wire that you'll use by testing for continuity to the jumper pins pin (in the row of 8 three-pin jumpers) furthest from the front edge of the board. These pins are directly connected to the 8 signal wires on the cable.
- Once you have the signal wire you want, mark and de-insulate it.
- solder the ground to the shield on the BNC cable, and the signal wires to each other. Don't forget to put some heat shrink tubing on the cables before soldering.
- Test the cable, and record some data.
...