Parallella Community

The placement of the tall cap was unfortunate...we are now testing to see if it's safe to remove it. So far so good...
In the future versions, these tall 100uF caps will be moved to to the bottom side.

Andreas

Very nice

Anyone running something like a 120mm computer fan on a couple of Parallellas? How do you power it?

Calle,

If you can find a 5V fan, then you can draw power from the board itself, as explained in the following post.

viewtopic.php?t=1049&p=6643#p6643

The other option is to use a standard PC power supply and use the 5V rail to power the board(s) and the 12V rail to power the fan(s).

Calle,

No problem, happy to help any way I can. As for using a PC PSU, I actually got the idea from several RPi Clusters that I have seen built, like in the video below.

https://www.youtube.com/watch?v=i_r3z1jYHAc

Seeing as I only have the initial Zedboard-based prototype and a Gen 1.1 Parallella board, as part of the EARLY-ACCESS pledge level, I really don't have much of a need yet for a PC PSU to power everything. Originally, I had planned on buying either a mini-cluster (4 boards) or cluster (8 boards), but upgraded my pledge shortly before the end of the KS campaign. Once they start accepting new orders, I will probably order at least a few more boards and build a small cluster.

As for powering a cluster of Parallella boards using a PC PSU, you could either connect the 5V rail to the mounting hole pads, like 9600 suggested, and power all the boards by connecting together with metal standoffs or build/buy several molex to barrel plug adapters and only power the boards via the barrel jacks.

At J15, to power a fan, is there any particular reason a U-shaped wire is recommended for soldering, instead of a pair of header pins and jumper ?

Yes, due to a "doh!" in layout, the J15 was placed directly above the samtec connector on the bottom side of the board.