Hello to all
I am a newbie to this site and I was searching for a transceiver to get used in my project , and I got the sparkfun site.
But I am not sure that which transceiver will suit my project the most.
Actually my project is consist of two AVR Atmega 16 boards which I have to interface with the GPS receiver and than I want to make these two boards communicable i.e. the GPS location taken by one reciever installed on one board should be transmitted to another board and the GPS location taken by receiver installed on other system should be transmitted to other board, and I want to display the location of each board on the LCD of another board, and the boards would be in the range of 200m.
But I am not able to choose that which transceiver will suit my this project the most and would be capable of transmitting and receiving the data accurately without any data loss within the range of 200 m .
So if you guys can advice me and let me know that which transceiver on the sparkfun site will suit the most than it will be very much helpful.
Thank you
If you want simple, almost plug and play, then use a pair of XBee series 1 (series ONE) modules. Line of sight in 2.4GHz with the right antennas you’ll get 200m. There is a PRO version that is a little more costly, but it will give you more fade margins for a long link. If one end of the link is immobile, you can put a patch antenna on it and greatly improve the range, if need be.
The XBee Series 1 come with stock firmware that does a “wireless serial port extension”. This would make a serial port on your AVR connect to the other unit’s serial port with the XBees in between, transparent after a one-time configuration.
These use IEEE 802.15.4 which does all the wireless packet flows, error correction, etc. In any wireless system, there will be uncorrectable error that your application must cope with, if the data is perishable. Commonly, you devise a timeout and try later or ignore the error, perhaps number each packet sent so the receiving microprocessor can know if a packet (frame) was lost despite the retries done by the XBees. This is called layer 2 error correction. You may need layer 3 error correction - in any wireless system.
XBee-Pro though you’ll need line of sight to get any range. If you want longer ranges get one with an external antenna jack and put a good quality omni. You don’t want to go too high with the gain though because the higher the gain the narrower the vertical beamwidth. A 5dB omni antenna is a good choice. If you go with 900MHz versions you get longer ranges non-line of sight and better foliage penetration. If you’re going for range and a robust signal then use a narrow bandwidth when you’re setting them up. It’ll drop the transfer rates but you’ll get more range and noise resistance.
http://www.ligowave.com/linkcalc/
This is made for WiFi/Wimax but the calculations are the same for the frequencies. It’ll give you an idea of the ranges you’ll get with the antennas you choose. You can enter custom radio stats you’ll find on the datasheets.