I want help in deciding which shield/module/board to do our project. 
We have to take input from and RFID tag, key board,GPS Sensor and a tilt sensor.
After authentication through RFID, it should allow a 9 digit numeric code via keyboard and location via GPS.
On activation of tilt sensor, this data along with location should be sent every second to a maximum of 2 kilometer distance wireless transmission in congested city, not in line of contact(without internet).
The other unit or units ( there may be one or more units) should receive this 9 digit code and location of the sender and activate two latchs (relays) in an interval of 10 seconds.
The receiver should display the code received and the location of the sender.
All units should have this sending and receiving facility.
All units should be similar in functions.
All units are receivers by default.
Transmission start on recognition of tilt sensor.
All units should have facility to add more sensors.
poojasalim:
to a maximum of 2 kilometer distance wireless transmission in congested city, not in line of contact(without internet).
Can you use a mobile phone network?
If not I think it will be almost impossible using the wireless frequencies that don't require a licence.
...R
If you can use a mobile then make an app according to your use with Mit app inventor for arduino with Bluetooth
In this app you can add GPS sensor also tilt sensor and many more and program according to your use and with Bluetooth module you can control your arduino output
You can also add a text box to your app which allows you to send any text to arduino and further take actions according to your programming , if Bluetooth range is enough for this then I suggest you my way of making app and further program arduino
And once again properly explain your project ....
Thanks
I cannot use any mobile network.
It should be like walkie talkie,without any speech,transmitting text messages to activate some latchs /relays along with GPS location of the sender.
can FM band be used for it?
Texas Instruments has a Transreceiver based on cc1120,which has a range of 2km,whether it can be used with arduino boards??
The range you get from a radio link depends strongly on frequency, power, antennas, datarate, terrain etc..
In built-up areas even relatively high power transmitters such as mobile phones communicating with well-sited base stations have dead spots...
And for a reliable 2km range you'd need quite a high power - probably not do-able on the unlicensed bands.
I think the texas device will only give that range with good antennas and a clear line-of-sight path.
regards
Allan
edit... actually the TI device ( presumably with an external PA ) runs up to 1W. - +30dBm
at 900MHz the path loss between two 0dBi antennas over 2km in free air would be approx
43 + 20log(number of wavelengths) => about 120dB => -90dBm at the receiver.
That's quite a lot - at 1200 baud datarate and a 10dB noise figure at the receiver
that would give a S/N of 43 dB . ( you get -174dBm/Hz noise from the universe ) For a decent bit error rate ( < 2% ) without FEC you'd need at least 12dB S/N giving approaching a 30dB margin for path losses.
Might be OK
r
A.
You may also run foul of the spectrum authorities depending on frequency and power.
Make sure the Tx is legal in your country.
Weedpharma
See http://www.ti.com/lit/ds/swrs112h/swrs112h.pdf.
TI say it's usable in various unlicensed ISM bands - check the regs in your country.
It quotes -123dBm sensitivity ( BER not given ) at 1Kbaud datarate, which is pretty close to my guess above.
So if you buy an approved module using this device, it may well work.
regards
Allan.
thank you... for reply
Frequency Band: 5.150-5.350 GHz, 5.725 - 5875
Frequency Band: 5.825 to 5.875 GHz
Frequency Band: 26.957-27.283 MHz
Frequency Band: 335.7125, 335.7375,335.7625, 335.7875, 335.8125 and 335.8375MHz
are allowable bands...
May i know which arduino board can be suitable for these range of frequencies..??
are allowable bands...
and what is allowable power?
Hint: this isn't an Arduino question
poojasalim:
thank you... for reply
Frequency Band: 5.150-5.350 GHz, 5.725 - 5875
Frequency Band: 5.825 to 5.875 GHzFrequency Band: 26.957-27.283 MHz
Frequency Band: 335.7125, 335.7375,335.7625, 335.7875, 335.8125 and 335.8375MHz
are allowable bands...
May i know which arduino board can be suitable for these range of frequencies..??
5 GHz will be useless in a built up area i suspect.
300 MHz band, maybe, if you can legally use 5 watts or so.
27 MHz band , the aerials tend to be physically large.
Hi poojasalim
To answer your questions need to check the regulations in your own country.
I think you'd need at least 0.5 watt output power around 300MHz with 1000 Baud data rate to be reasonably reliable - and the receiver should have a suitably narrow IF or digital filter to achieve this.....
check your country's regulations for the permitted power level.
As for suitable modules - try Google. Designing and getting approvals for such devices is expensive!
regards
Allan.
I used to use walkie talkies professionally in London.
2W i think at VHF.
10 miles radius although we had base stations on tall buildings.
You do not say where you are.
The ameteur radio community uses packet radio which may solve your problem, they have allocated frequencies for free provided this is not for commercial use.
Hi Boardburner2
Sounds a bit like the trunked TETRA system... or the earlier MPT1327? I've worked on both....
regards
Allan.
thank you......
List of Licence free frequencies in India for Wireless usage
Frequency Band: 865-867 MHz
Low power RFID equipments or any other low power wireless devices or equipments
Power: Maximum transmitter output power of 1 Watt ( 4 Watts Effective Radiated Power)Carrier Bandwidth: 200 KHz
Frequency Band: 2.4-2.4835 GHz
Use : Low power equipments
Power: Maximum transmitter output power of 1 Watt ( 4 Watts Effective Radiated Power)
Carrier Bandwidth: spectrum spread of 10 MHz or higher
Frequency Band: 5.150-5.350 GHz, 5.725 - 5875
Use : Low power equipments for Cellular telecom systems including Radio Local Area Networks, Indoor applications
Power: maximum mean Effective Isotropic Radiated Power of 200mW, maximum mean Effective Isotropic Radiated Power density of 10mW/MHz in any 1 MHz bandwidth,
Carrier Bandwidth: 1MHz
Frequency Band: 5.825 to 5.875 GHz
Use : Low power equipments
Power: maximum transmitter output power of 1 Watt ( 4 Watts Effective Radiated Power)Carrier Bandwidth: spectrum spread of 10 MHz or higher
Frequency Band: 26.957-27.283 MHz
Use : Wireless equipments intended to be used while in motion or during halts
Power: maximum Effective Radiated Power ( ERP) of 5 Watts
Frequency Band: 335.7125, 335.7375,335.7625, 335.7875, 335.8125 and 335.8375MHz
Use : Low power equipments for the remote control of cranes
Power: maximum transmit power of 1mW
Carrier Bandwidth: 10 KHz
TI do a evaluation module to get you going which covers those frequencies....
try CC1120EMK-868-915 Daughter card | TI.com
regards
Allan