What rf to use?

Hello all, i'm new to the forum.

I don´t know a lot of things about rf, so, i need your help XD.

To my project i need an rf that can communicate up to 1km (if it can reach 1.5km better) and if it is easy to program better. It must send position, data from accelerometer, gyro, compass, etc

During my search what i found was:

openbee - http://www.flytron.com/open-source-hardwares/210-openbee-100mw-telemetry-module.html apc220 - http://www.ebay.com/itm/APC220-Wireless-GPRS-DTU-Data-Communication-Module-USB-Adapter-Kit-For-Arduino-/390640131854?pt=LH_DefaultDomain_0&hash=item5af3f75f0e rfm22 - http://www.ebay.com/itm/RFM22B-433Mhz-Wireless-Transceiver-from-HopeRF-/171233339768?pt=LH_DefaultDomain_0&hash=item27de4d6978

Openbee for a open project didn't found anything, no examples, nothing. apc220 is the one that has more examples rfm22 some tutorials, some questions in this forum, but most with unconclusive answer ( that was what i thought)

In the project i'm using an arduino uno.

Can you help me finding what is the best rf module for my project (can give other examples of modules, if they are better) and some examples? :D

Ps: if this is not the right place for the post, please move

Grateful

What is legal in your country ?

If you buy something on Ebay, that tells “2km range”, it might be just 500 meters.

In my country the Walkie-talkie at 446 MHz is legal to use without license. Those can have a range of a few kilometers. But I don’t know if it is allowed to send digital data with them.

You find a lot information if you google for: arduino long range rf

Caltoa: What is legal in your country ?

If you buy something on Ebay, that tells "2km range", it might be just 500 meters.

In my country the Walkie-talkie at 446 MHz is legal to use without license. Those can have a range of a few kilometers. But I don't know if it is allowed to send digital data with them.

You find a lot information if you google for: arduino long range rf

First of all, thanks for your reply.

In my country it is legal to use 400-460MHZ, no problem. This is for a project, they recommend us to use this kind of frequency, so i think that there isn't any problem. As i already mentioned, it will be used to send gyro, accelerometer, gps and pressure info to the base controler. FOr the 1.5km what is the most recommend rf module (the one that has more support, tutorials, etc)?

These are the ones that you found already, they are sometimes used with the Arduino, but not a lot. http://www.dfrobot.com/index.php?route=product/product&product_id=57

These have a longer range: http://www.dfrobot.com/index.php?route=product/product&product_id=375

But you have to be sure that an up-to-date library is available for the Arduino.

Sometimes those modules are initialized with software on a computer, and after that the Arduino can connect to them with normal uart serial data.

Caltoa: These are the ones that you found already, they are sometimes used with the Arduino, but not a lot. http://www.dfrobot.com/index.php?route=product/product&product_id=57

These have a longer range: http://www.dfrobot.com/index.php?route=product/product&product_id=375

But you have to be sure that an up-to-date library is available for the Arduino.

Sometimes those modules are initialized with software on a computer, and after that the Arduino can connect to them with normal uart serial data.

I just found this one: https://www.sparkfun.com/products/11634

Do you think that xbee could work? It says that it has more than 2000 feet range. With the antenna it can have 9miles range

Yes, that could work. Sparkfun has more for long range: https://www.sparkfun.com/pages/xbee_guide I have not taken notice of them before, because those long range modules are all illegal in my country.

There was a problem with a pin as I can read in the comments. I can also read that you need a good antenna.

You need a shield between the Arduino and the XBee: http://arduino.cc/en/Main/ArduinoWirelessShield

I don't know if they are legal here, but they will be used in a contest, so, i don't think there is a problem.

The only problem is the price, 60$ just for one module. There must be some less expensive?

You said i will be need a good antenna. The module can be used without antenna, right?

Grateful

You can use Xbees without an antenna, but the range will be very limited, 10 metres or less. To get any decent range, you will need a good external antenna.

  1. you have to check whether it is legal in your country
  2. mind the antennas are not omnidirectional, especially for 2.4GHz band. In order to have a connectivity to 1.5km with such low power module you need the antennas point to each other, otherwise you will loose the signal.

Ok, so i think that for the price and all the problems, xbee are out.

There isn't any good rf module for arduino?

HI, pls check this link for alternative of XBEE modules.
http://www.appconwireless.com/PRODUCTS/showproduct.php?lang=en&id=7

RF control for a kilometer or better usually runs into countries law and regulations covering transmitter power out for unlicensed use.

For distances like this, its important to know whats in between the transmitter and receiver. Do you have line of sight, ie can you see from one end of your path to the other. Most of the low power transmitters that claim distances like this also need line of sight.