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2008 design will use gumstix as main proc - with gumsense as wake-up device. It will wake up once a day at noon GMT for long range coms to UK. An ssh tunnel will let us login then from UK.


  • ttyS0 - for probe coms/net
  • ttyS1 - GSM/GPRS ? depends if rts/cts needed
  • ttyS2 - for GPS (if needed) - will tell dGPS to start/stop recording

usb - usbnet to laptop?

GPIO - control BatV relays for GPS and GSM units (offboard if gumsense can't cope)

ADC used for BatV

I2C for a temp/hum sensor

Base box specs

Has these external connectors (pref Mil spec):

  • GPS antenna TNC
  • GSM antenna (wierd smb waterproof con - probably not so great after all)
  • rs232+pwr to wired probe (mil)
  • PWR in - from solar (mil)
  • PWR in - from Wind (optional)

Note the MIL connectors are Amphenol plugs (MS3106A-14S-2P) with strain (97-3057-1007-1) plugging into 4 way socket (MS3102A-14S-2S). Expensive but the toughest we have ever used!

Base Box parts

  • clean, reinforce/seal Peli box
  • gumstix (in mini box)
  • regulator for solar/wind
  • 2-3 12AH 12V Batteries
  • GND and BatV coupling
  • 10W solar panel (on top of box) - uses windy's regulator
  • wind generator

Base job

A script on the base is run when it wakes (mainly Python this time). This does something like:

if batV OK
 powercontrol gps on
 start GPS recording
 (ping all probes and store RSSIs) using probeping
 (fetch probe data) probegetdata (Write to files)
 put probes to sleep (if not done in above)
 get base data (eg BatV, Temp)
 tarball new data onto flash

complete gps job if it ran:
 stop GPS recording
 fetch gps file
 powercontrol gps off
coms job:
 powercontrol coms on
 open GPRS coms - maybe wait for good signal with timeout
 try to send (rcp) all unsent data
 start ssh tunnel
 if stayup sleep for a while (allows remote access) 
 close gprs ppd
 powercontrol coms off
sleep (poweroff)

CF card

Format could be ext3 - without atime and possibly turning on "barriers" to make it more secure (see http://lwn.net/Articles/283161/). We have an industrial 1GB CF from sandisk in base. It needs certain directories to exist on it (queued archive data).

to use ext3 filesystem - we need "noatime,nodiratime"

In the end a specific vfat is needed - beware!

Both Iceland and Norway systems had some kind of CF errors eventually :-(