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Topic: I want to build an autonomous GPRS weather station (Read 25547 times) previous topic - next topic

aerozg

#45
Dec 21, 2010, 03:36 pm Last Edit: Dec 21, 2010, 03:37 pm by aerozg Reason: 1
Yes, the 4 minutes ringed a bell, i immediately looked it up, the manual says the base station needs approx. 4 minutes to sync with the sensors, but only for the first time you set it up, or when you need to change the batteries. It doesn't say it syncs every 4 minutes on its own. Are you suggesting that it is? Because if that signal is complex as you say it is, than that's got to be it.

"Data stored for further processing" could mean only one thing, it is stored in temporary memory and used to calculate the average values of wind speed, wind chill and possibly everything else measured.

jumpjack

#46
Dec 21, 2010, 04:54 pm Last Edit: Dec 21, 2010, 05:00 pm by jumpjack Reason: 1
Quote
Yes, the 4 minutes ringed a bell, i immediately looked it up, the manual says the base station needs approx. 4 minutes to sync with the sensors, but only for the first time you set it up, or when you need to change the batteries. It doesn't say it syncs every 4 minutes on its own. Are you suggesting that it is? Because if that signal is complex as you say it is, than that's got to be it.

I only saw that the 4-mins signal is 3-4 times longer than the 30-secs signal, didn't examine it.


Quote
"Data stored for further processing" could mean only one thing, it is stored in temporary memory and used to calculate the average values of wind speed, wind chill and possibly everything else measured.

It's just my idea, I didn't read it anywhere. Don't know if there is onboard processing in sensor.

GregaG

About the gsm maybe u should check
http://hackaday.com/2010/10/18/cheap-and-easy-sms-via-gsm-for-your-mcu/
http://code.google.com/p/sserial2mobile/
and if it has to be a module, i think this 1 is 1 of cheapest, i might be wrong
http://www.cooking-hacks.com/index.php/arduino-gprs-module.html

aerozg

Thanks for that post from HackADay, it will help. Sserial2mobile i found a month ago and i'm looking into it. And the Arduino GRPS module is indeed one of the cheapest i have seen yet, i think i will get that one.

jumpjack

GPRS modems for 25$ is a very cool news, thanks! But I see I should connect the modem to the arduino through TX and RX pins of a pl2303 chip, which is just an USB-serial converter; as such a converter costs around 10$, should we guess that some GPRS serial modem exist and are sold for 15$ ?!?

aerozg

GPRS serial modems do not come cheap, they cost around 130$+ or even more.

http://www.smsco.it/tomcat/en/buy/show.do#modem



jumpjack

What about the wavecom at the end of this page?
http://www.carrideo.it/shopping2.htm

Any datasheet available?

aerozg


SnJDK

Just capture signal isnt good enought without knowing what exactly system send.

"Wind" device basicly have 4 sensors :
1) Wind Speed
2) Wind orientation
3) Outside temperatura
4) Outside humidity

I did some research becouse I need that device to send data via 1-wire network, but finaly I decide to use both information (I like wide LED screen :) )

What sensor is used :

1) Wind speed (reed switch)
   Half period on / half period off (not so usual but O.K.)
2) Wind orientation (not sure at the moment)
   From outside device come 7 wire, 2 of them are for Wind Speed , so
   we have 5 other , 16 orientation of wind , that mean 2^4, 1 wire in 4
   out maybe digital/or analog
3) Outside temperature (Normal thermo resistor)
   Analog value
4) Humidity sensor (Low lewel)
   Measuring resistance beatween two cooper field

Rain gouge
Standard dual reed switch system

If I am on your place I will use rein gouge for testing and alayzing signals.

When I finish 1-wire implementation I will send more info on forum.  

aerozg

Thank you for the info,  i'm also using the rain gauge for testing and have come to the same conclusion. But i will try a different approach, my idea is to try to patch in to the base station itself and somehow extract the data. It receives the sensor data, calculates and displays it on the lcd. There has to be a way i can intercept the displayed calculated values.

ravenpow

Hi everybody.
I also got the auriol weather station and would like to interface it  to the pc.
Aerozg i like your approach , i am looking forward for your results.

SnJDK

Some small changes :

Rain gouge :
* only one reed switch, count off state (which is very unpractical, battery life)
* 1-wire ready (4N25)

Wind station:
* wind speed count Low state (GND) - 1-wire ready (4N25)
* wind orientation is reed short time before sending data and very probably used 4 reed switch and few diodes

I have few picture of inner PCB which will be posted later.

Finally, in my opinion it will be very hard to decode radio communication from central device, because electrically all 3 devices are different construction, and doesnt seam to be from same source.

Especially central device isnt good example how to create industrial PCB :) (it look like amateurs work).

SnJDK

Wind orientation on central device display dont show exat position at measuring time (maybe I need to configure something :) ).

Algoritam of orientation presentation is very upredictable, it doesnt appear it is avrage position after few reeds. It show some adding behavior, but still upredictable.

Aerozg if I understand correctly you study aerospace engineering (FPZ) maybe you know what algoritham is used for wind orientation presentation ?

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