02 April 2012

ks14 update2

It's been awhile, with less progress than I'd like. But it's not a race, I'm trying to do it better vs faster.

The Aluminum clipboard case worked out great for the enclosure. Thanks again to @B11011G for the idea.

Enclosure with RF and power plugs installed so far

The RF stuff is all mounted and cabled. LNA power is temp'ed in for now.
RF stuff mounted+cabled, USB is inwork

Close up of enclosure business end. This will get USB connectors next(or ethernet if i can fit a server/drone SBC inside)

I've ordered a 12V to 5V DC-DC converter to put inside which will let me run the whole thing off 12V to run the LNA and also provide 5V external power for the USB stuff.

In the mean time I'm trying to figure out how to squeeze the USB hubs in the remaining space and improve their shielding. The ultra cheap hubs I bought have no shield in the cables, plus I'm partly disassembling them to fit. I've contemplated soldering in new USB cables to the hub that I can more cleanly route to the radio. I have a batch of other cheap 99 cent cables but they aren't shielded either. I could wrap them up in foil or foil tape..... not exactly doing it "better" like I claimed above. I think it might be worth trying before I buy 14 shielded USB cables to cut up and find that they don't make enough difference at only 6 inch length.

I'm finding that having these 14 radios on USB can be pretty unreliable. I'm not yet sure if it's the lack of cable shielding described above, 5Vpower issues(currently I'm using separate wall wart power supplies to each hub), or underpowered hosts.

The 14 devices worked perfectly well on the Core i7 desktop for the 14 Stick Shootout. But the Atom 330 from before and the Seagate Dockstar I tried the other night were pretty flaky with it. On the Dockstar even U-Boot was having trouble reliably initializing the USB bus and booting from a USB memory stick. I think I'll play with skipping the U-Boot USB scan and just doing a netboot of Openwrt initramfs kernel (I've been leaving the original Seagate firmware in the onboard NAND chip).

The Dockstar board would fit inside the enclosure and the whole package would be the server instead of just a peripheral for another server box. But, I'm not sure it can handle the job since it's just a 1Ghz ARM... that's what I'm trying to find out before I hack it up to fit in the enclosure.

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