# Weather Station

Hi, i’m new on arduino word but have few experience with raspberry pi and have a computer degree.
So i’m thinking make a weather station (with a arduino outside my house and send data to Rpi= and a Rpi0 inside to mesure inside temperature and do data processing), i’m researching for a few days and thing this is what i want from the arduino side Projetc diagram.
As the arduino will stay on the outside without power socket, i need to make it most efficient possible but i did not know who do a calculation of power consumption with this configuration. I’n thinking use a battery pack (for example AA Baterys) or a powerBank whit a solar panel to charge it. Can some one help do this? and if you think is best replace some components with more power efficient ones that offers the same functionality please say

The most power consumer is probably the radio link, if you make measurements at 10 seconds, radio updates every minute, and sleep in low power mode in between, a 100mA 6V solar panel and a battery should be enough to keep it running

I forgot to teel, my expectations are take mesures every 15 minutes, and send the data after that. And have the idea of this device running 24*7, on some youtube videos that i saw people taking mesures this what the came with.

No RFtransmiter (temperature and pressure)
Sleep 2.81mA
Taking Data 7mA (2 seconds)
other Video that measures RFtransmiter Sensor power consumption
RFtransmiter Sensor
off 0.0084mA
transmitting 13mA (expect in the worse case it will take 2 sec for each data transmition)
I suppose use the lowest data transmission Rate (256Kbps) and low power to on the arduino
So with sone naive calculation a came getting (when i'm reading data will has de transmitter off and when send will power Off the sensors)
Total system
Sleep 3mA
Read 7mA
Transmite 15mA
(average of 3.04 mA)
what with a 4*AA 3000mAh batteries gave a total working of 115 days (output of 4.8V 2A)
If my calculations are close to reality if i add a power cell to the system i'm able to run it forever

Yes, an average consumption of 4mA will be supplied with no problem by a 100mA solar panel, if you have a big enough battery to get it over the darkest/cloudiest days. Or worst case, a few weeks of snow cover.

Where i live don have that kind of problem with snow
Thanks again

I have also made a weather station, very fun project to do.

There are lots of possibilities to build one. For mine I used an ethernet shield so I could hook the station to the internet. You can write a processing sketch which can log in to your station and makes graphs of your data etc. I used Power over Ethernet to supply it with power.

But if you cannot get an ethernet cable outside (I drilled a hole through a window frame in the living room) and you are stuck to batteries (and solar power!). There are other ways to conserve power.

What I really urge you to do, is to get an SD card holder to store your data and to get an RTC module such as a DS1307 or DS3231. With an RTC your station knows how late it is and you can use timestamps when you store data on your SD card. The RTC and SD card holder are cheap things, you can get them for 5€ togather if not cheaper.

The best way to conserve power is to turn off your station. I mean during night time you won't be requesting data from it. It is not hard to devise a small circuit with which the arduino can cut off his own power supply by making one of I/O pins high or low.

The DS3231 has an inbuilt alarm, when this alarm gets triggered the RTC sends out an interrupt signal. You can use this interrupt signal to power up the entire circuit. Than the arduino can take sensor readings, store the readings in the SD card, set the new alarm time for the next hour and when he has done all that, the arduino disables himself again to be woken up again over 59 minutes.

During day time you can leave it on, but perhaps you can also think of something to use your transceiver to initiate the power up, you can also take a look into bluetooth, wifi and Zigbee modules. Those come in low power consumption variants

In the image you can see a simple circuit, both RTC and transceiver have the ability to power up the circuit and the arduino can disable the power by writing an I/O pin high.

Yes, that's nice. What is the "s r M" square in your circuit?

some RTC modules embed an 24c32 EEPROM, that can take 1million erase cycles. I mean, instead of SD card.

blimpyway:
Yes, that's nice. What is the "s r M" square in your circuit?

some RTC modules embed an 24c32 EEPROM, that can take 1million erase cycles. I mean, instead of SD card.

that M is a symbol for a memory cell with a Set and Reset Input, you can build one using some cheap IC with NAND or NOR gates. (the one has a dominand Set and the other a dominant Reset). If you buy one IC with 4 inbuilt NOR gates you have what you need.

And I find an SD card very convenient and easy to read and write from/to. When I ask my weather station about the data of the last 24 hours, the arduino will read the entire SD card, scanning for a certain timecode of 24 hours before now. When it found the timecode the arduino will continu reading the SD card and transmit the remaining data. Plus you can pull out the card if you ever want to.

very nice ideas @bask185 but i do not want the arduino to store any data only read and send it.
The RTC with interrupt is a very nice idea to save power this weekend i will make e shopping list and see what i really will use (now i only have the Rpi will be my first project using Arduino) then i will post it here.
I'm thinking about use the arduino pro mini dou you think other one will be best?
I also have a usb to ttl board that i used to flash my calculator can i upload code to Arduino with this ore need other?