|Intel NUC, CEC, USB
The Intel Next Unit of Computing PC's are great hardware for HTPC application and such.
These PC's come in three different versions, DC3217IYE, DC3217BY and DCCP847DYE. And each of these
versions is available as bare mainboard or kitted, which means it comes with a nice small case.
Obviously, for most purposes, these cased versions are most suitable.
Unfortunately, some penny-picker at Intel decided that it was benificial to remove a few parts from the mainboard that is to belivered in a case. These removals include the 2-pin MiniFit header for power entry and the two internal USB connections.
For a typical HTPC, you might want to add a USB-CEC adapter or to have an internal remote control receiver. So it is quite beneficial to have those USB connections after all.
If you want these ports and don't care about warranty too much; here's how:
1) Remove the solder from the unpopulated PCB holes and solder a 2x4-way 100mil header into the holes.
Removing this solder is quite difficult, particulary the solder on the ground pins. Power and signal
pins were not much of a problem, but for the ground I had to resort to 'drilling' through the solder
using the tip of a pair of tweezers.
2) Solder a 4xZero-ohms resistor array in 1206 package into this empty spot at the bottom (CPU side) of
the mainboard. Alternatively, this can be done with 4 tiny pieces of wire strand. Originally, this
spot is supposed to contain a quad array of EMI inductors, but for the purpose of adding internal
USB devices, this does not matter. Also, the empty component spot next to this inductor is for an
ESD suppressing device. Again, not needed when users don't have access to the port. (Of course, as
the builder you better take some anti-ESD measures, but you were doing that anyway, wheren't you?)
USB-CEC for HTPC applications:
Extra modifications for adding an internal USB-CEC adapter:
The internal USB-CEC adapter from Pulse-Eigth requires a couple of non-standard signals. Obviously the CEC signal
from the HDMI connector and also a permanent 3.3V power supply. Both signals can be aquired from the NUC mainboard
by soldering a couple of signals into place:
Finally the USB-CEC can be connected to the CEC signal, 3.3V power supply with GND, one of the USB headers,
and to the power-button header. The USB part was cut from the USB-CEC cable assembly and soldered directly onto the
PCB pads. For the other signals, a special cable assembly was made to allow for removal of the USB-CEC board. A standard 100mil
4-way header is wired with 3.3V (yellow), ground (black), CEC (white) and PowerButton (blue). By soldering
a piece of headerstrip onto the CEC board and jumpering two of the second-row connections to unused pins on the first
row, a compact assembly could be realized.