Current preferred spec

Case & PSU

  • Item: Cypher AK-ITX-04BK Mini-ITX from Akasa with 120W PSU VESA Mountable
  • Manufacturer: Akasa
  • Description: Small computer case
  • Supplier: scan
  • Supplier product code: LN45102
  • Web page: http://www.scan.co.uk/products/akasa-cypher-ultra-compact-mini-itx-case-black-with-120w-psu
  • Number required: one
  • Price (ex VAT): £44.98

This case has a “brick” PSU which should work with the 12V power input on the DN2800MT motherboard. Lovely small case. Has a hole for an RP-SMA connector (antenna). Just about enough space to mount a Nanode SMT inside.

The plug on the PSU which comes with the case is too big to fit the mobo. The mobo needs a “8 - 19 VDC external power supply though the DC jack on the back panel. This connector accepts dualbarrel plugs with an inner diameter (ID) of 2.5 mm and an outer diameter (OD) of 5.5 mm, where the inner contact is +8 (±10%) through +19 (±10%) VDC and the shell is GND. The maximum current rating for this connector is 8 A.” (from p58 of the mobo manual.) So it’s necessary to chop off the HUGE connector on the PSU (which has an outer diameter of about 7mm and an inner diameter of about 5mm) and replace it with:

  • Item: CONN PWR PLUG DC 2.5X5.5 8A MOD
  • Manufacturer: CUI Inc
  • Description: DC plug with 5.5mm OD, 2.5mm ID, 14mm length (and locking groove? TBC)
  • Supplier: Digi-Key
  • Supplier product code: CP3-002BH-ND
  • Web page: http://www.digikey.co.uk/scripts/DKSearch/dksus.dll?Detail&itemSeq=127910444&uq=634992759972123594
  • Number required: 6
  • Price (ex VAT): 1.30

Motherboard

  • Item: Intel DN2800MT Atom motherboard
  • Manufacturer: Intel
  • Description: mini-ITX motherboard with built-in Atom CPU
  • Supplier: Scan
  • Supplier product code: LN43166
  • Web page: http://www.scan.co.uk/products/intel-boxdn2800mt-mini-itx-intel-atom-n2800-motherboard-ddr3-1066-so-dimm
  • Number required:
  • Price (ex VAT): £66.28

(also available from Micom)

The N2800 Atom has enhanced speed step so should be capable of consuming just a few watts. It uses a PowerVR GPU which has virtually no Linux support. But that’s not a problem because it’ll be a headless data logger..

WiFi

  • Item: U.FL-RPSMA BULKHEAD MOUNT, 200MM
  • Manufacturer: GIGATRONIX
  • Description: Antenna cable
  • Supplier: Farnell
  • Supplier product code: 1706348
  • Web page: http://uk.farnell.com/gigatronix/u-fl-rpsmabulk-200mm/u-fl-rpsma-bulkhead-mount-200mm/dp/1706348
  • Number required: one
  • Price (ex VAT): £6.42

Cheaper cables are available from Amazon but I need to use a college-approved supplier. Farnell 2143312 would also be a cheaper option (£3.50) but wasn’t in stock when I ordered.

  • Item: RN-SMA4-RP - ANTENNA, 2.4GHZ, 4INCH W/ RPSMA
  • Manufacturer: MICROCHIP
  • Description: WiFi antenna
  • Supplier: Farnell
  • Supplier product code: 2143322
  • Web page: http://uk.farnell.com/microchip/rn-sma4-rp/antenna-2-4ghz-4inch-w-rpsma/dp/2143322?Ntt=2143322
  • Number required: one

  • Price (ex VAT): £4.08

  • Item: Centrino Wireless-N 2230

  • Manufacturer: Intel
  • Description: mini PCIe wireless network card
  • Supplier: Micom
  • Supplier product code: 2230BN.HMWWB
  • Web page: http://www.micom.co.uk/intel-centrino-wireless-n-2230
  • Number required: 5
  • Price (ex VAT): £11.65

This plugs into the motherboard. It’s designed to use two antennae but it seems to work fine with one antenna on my 802.11g network. There are lots of Intel miniPCIe adapters. Some have draft-N support only. Some have Bluetooth (which I don’t need). Cheaper adapters can be found on Google but this 6230 adapter is fairly cheap and comes from an approved supplier; plus Intel WiFi adapters should have good support on Linux. Insight also do the WiFi Link 1000 and Wireless-N 1030 (both for £9.99 ex VAT) but these are “order upon request”.

Hard drive

  • Item: Seagate Momentus 320GB 5400.5 2.5” Notebook Hard Drive
  • Manufacturer: Seagate
  • Description: Hard disk drive
  • Supplier: Scan
  • Supplier product code: LN26698
  • Web page: http://www.scan.co.uk/products/320gb-seagate-st9320325as-momentus-54005-25-95-mm-sata-3gb-s-5400rpm-8mb-cache-14ms-ncq
  • Number required: one
  • Price (ex VAT): £28.32

The system draws ~14W while logging (but with a power factor of only about 0.35)

Build order:

  • Take top off case
  • Remove HDD bracket
  • Fit back plate
  • Fit motherboard
  • Fit WiFi aerial cable
  • Fit WiFi mini PCIe card & connect to aerial cable
  • Fit cables from case to motherboard
  • Fit HDD to bracket and install in case and fit cables

Additional notes

Electronics

  • Item: HEADER, RIGHT ANGLE, 6WAY
  • Manufacturer: TE CONNECTIVITY / AMP
  • Description:
  • Supplier: Farnell
  • Supplier product code: 1248172
  • Web page: http://uk.farnell.com/te-connectivity-amp/826947-6/header-right-angle-6way/dp/1248172
  • Number required: six
  • Price (ex VAT): £0.199

The header is required because the header supplied on the NanodeRF SMT isn’t right-angled, so the FTDI adapter sits at right angles to the Nanode, and this configuration won’t fit in the tiny Atom case. So we need to replace the straight header with a right-angled header.

  • Item:
  • Manufacturer:
  • Description:
  • Supplier:
  • Supplier product code:
  • Web page:
  • Number required:
  • Price (ex VAT):

Motherboards

D945GSE

  • Tech specs PDF
  • Min power draw = 12.28 W
  • Max power draw = 42.01 W
  • Audio is ICH7-M with ALC662 audio codec
  • “Front panel audio header with support for Intel High Def Audio”
  • NO LINE IN (see table 4 on p21 of tech spec PDF)
  • N270 (2.5W TDP)

continued…

D2700MUD

  • Tech specs
  • £57 inc VAT on eBuyer
  • Min power draw = 23 W
  • Max power draw = 88 W
  • Atom D2700 (no enhanced speed step. speed step doesn’t appear to be available at all in Linux on this CPU)
  • Two SO-DIMM slots for 1066/800 MHz DDR3 single-channel memory
  • SATA 2.0 Gb/s
  • VGA and DVI-D ports
  • Audio Intel NM10 and Realtek ALC662
  • Line in is definitely supported. Not clear if second line in also supported???

D525-based boards

  • Has much better Linux support for GMA
  • But appears to have no CPU freq throttling support on Linux (or Windows?)

Audio

Realtek ALC662 audio codec

  • tech specs
  • two stereo ADCs, 16/20-bit PCM format, 44.1k/48k/96kHz sample rate
  • All analog jack port are stereo input and output re-tasking
  • Up to four channels of microphone array input are supported for AEC/BF application

Complete PCs

There are lots of “nettop” PCs which are very cost effective. But finding one with an N2800 Atom (with enhanced speed step), audio line-in, and just enough space to install a Nanode inside, and a padlockable-case is tricky (although it’s a little ambiguous whether the mic-in ports on these nettop PCs can be re-programmed to be line-in ports). The Lenovo Q180 is impressive.

http://www.ebuyer.com/store/Computer/cat/Nettop

LGX AG150

  • 1.86 GHz N2800
  • fanless
  • expensive!

Misc notes on college-approved suppliers

misco

  • has nice mini-ITX cases with silent PSU but only usable if I can find mobo with WiFi http://www.misco.co.uk/Product/162779/Akasa-Crypto-Compact-Mini-ITX-Case-60Watt
  • has no Atom mobos
  • has cases of a similar form factor to the one I have

BT

MICOM

  • one expensive (£62 ex VAT) Atom motherboard: http://www.micom.co.uk/intel-dn2800mt
  • does have a Gigabyte GA-C847N http://www.micom.co.uk/gigabyte-ga-c847n-motherboard
  • several cases eg: ** http://www.micom.co.uk/aopen-s135b (60W silent PSU. don’t think this will take an expansion card though) ** Antex ISK 310-150 http://www.micom.co.uk/antec-isk-310-150 (1 half-height expansion card) ** http://www.micom.co.uk/cooler-master-elite-120-advanced ** http://www.micom.co.uk/aopen-h340a
  • Zotac ZBOX SD ID12 Barebone PC Intel Atom Dual Core (D525) £117 ex VAT

SCAN

  • Akasa Cypher mini ITx with 120W PSU and what looks like an SMA hole £44.98 ex VAT http://www.scan.co.uk/products/akasa-cypher-ultra-compact-mini-itx-case-black-with-120w-psu
  • http://www.scan.co.uk/products/akasa-euler-ak-itx-05bkal-mini-itx-for-intel-dq77kb-ivy-bridge-intel-dh61ag-sandy-bridge-motherboard
  • several cases with DC PSUs (not what we want)
  • Nice Zotac NM10-E-E Atom D525 mobo with wifi for £70 ex VAT but pre-order
  • Nice Zotac NM10-F-E Atom D525 with wifi for £60 ex VAT but pre-order
  • Mede8er wirless mini pcie card with aerial £24.89 ex VAT http://www.scan.co.uk/products/mede8er-med20pcie-wireless-n-minipcie-upgrade-5db-kit