2008baseconfig

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.

ports

• 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
probejob:
 (ping all probes and store RSSIs) using probeping
 (fetch probe data) probegetdata (Write to files)
 put probes to sleep (if not done in above)
basejobs:
 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
 startpppd
 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 :-(