wlan-slovenja currently develops an IO-shield for an cheap microcontroller development board http://dev.wlan-si.net/ticket/1050
maybe a nice, cheap and outofthe box useable solution for poweycling boards are managed poe switches
and a really cheap one (and infact a router not just a switch) is the mikrotik RB750UP
5port switch, switchable poe passthrough for 4 ports maximal 500mA (24 bzw 28V) i.e. ~12W max. per device current monitoring (but not really ready yet) over-current shutoff (which might create problems with higher powered bootup draws) 1x usb 50$ ? poe switching useable with openwrt? infact the (RouterOS) poe-driver kernelmodule is tagged as gpl, but remember this is mikrotik )-; btw. mikrotik has an switch with SwOS too that has controllable Poe ports, and in SwOS the current monitoring should already work!
ubiquity announced a similar productline too (THOUGH-Switch). Specifications?
There is a 5 port 24V or 8 port 24/48V version, and they might have no problem in powering/switching 20W boards (or at least an N2800MT should work)
and there are real switches too for 50$, with 4 802.3af ports, but having 48V is likely no benefit for us (we would need 802.3af to passive poe adapters) http://www.i4wifi.eu/TP-Link-wired-1/TL-SF1008P-8-ports-10-100-Mbps-PoE.html (max 15.4W (~300mA) per port!)
just powercycle or more?
for a board to be useable as a storage device, to do an receover boot of the research device from it needs an client or OTG capable usb port, not “just” host ports.
nice: carambola 17-22€ 2xLAN, 2xCOM, USB, GPIO, (SPI), 320Mhz raMIPS, 32MB RAM, 8MB flash, 2mm pinheader, development board anaother 17-22€ the carrier has the lan physicals, i.e. outofthe box the small board can not do lan
a bit faster, atheros wifi, and likely more power efficient, and as complete router (ufl, 2xlan,usb,32mb ram, 8mb flash) even cheaper (36$): Alfa Hornet-UB Embedded Board Atheros AR9331
but gpio only available with unsolder/reuse led, caution there are 16/4 and 32/8 (RAM/Flash) variants! similar:: [[http://www.ciudadwireless.com/alfa_network_aip-w502u_pcba_802-11n_router_board_port-p-5161.html|Alfa Network AIP-W502U PCBA]]
another ramips based openwrt board 35 GBP (mit stm32 expander (coudl act as storage device, lion chargen, gpio, onewire)): Omnima advanced automation systems same company offers also 220V switches, but expensive ones.
there is also an extension board to support another 4 relais http://i4wifi.cz/rozsirujici-modul-k-lan-ovladaci-4-x-rele_d2989.html