reception pc rf 433
I am newbie in RF world. I have worked on embedded designs extensively but never get in touch with RF world before.
I am designing >20 clients (Embedded systems) and 1 master (PC) based system. clients will transmit data and master (PC) will save those data.
My queries are-
1. What are the preferred 433MHz RF modules? How will I choose a suitable one? And what is the price range?
2. I found 433MHz RF modules saying 2 channels, 8 channels etc. Does that mean it can connect to 2 or 8 other modules concurrently and send/receve data?
3. How can I connect several clients with master at the same time to receive data?
4. Is there any protocol (built-in/open source) for 433MHz communication? How to find out data missing and errors and handle those errors?
5. Is there any encrytion/decryption to protect from data theft?
Googling for specific information made me confused. Please advise me some tutorial, links, design examples etc.
Thanks in advance.
Check these manufacturers and their application notes:
http://www.nordicsemi.com/index.cfm
http://www.atmel.com/products/smartRF/default.asp
http://www.microchip.com/stellent/id...GE&nodeId=1488
I found some modules from a chinese company Sunray or Tangray. What is the quality of those products? How to compare the qualities of RF stuffs? Although they didn't mention anywhere but it seems they used chips from TI and Atmel.
Any suggestion on the modules?
You really need to supply more information on what you intend to do if we are to give better help!
Hi,
Thanks a lot for your invaluable information.
In fact I am going to work in a datalogger which will communicate via RF. I need ~500 meter range but highest possible data transfer rate. Also it should be duplex (or at least half duplex) transceivers.
In the mean time I found several CC1100, CC1101 based modules. some of those with SPI, others have TTL or rs232. Since I am already using a microcontroller so I guess SPI is enough.It will also save some bucks.
Please suggest me which modules to choose, how the quality differs etc. (TI evalaution kits are way more costly where as I can not identify which chinese solutions may be better.)
Thanks once again for your help :)
Why 433 MHz? Why not 2.4GHz?
Have a look at these modules:
http://www.sparkfun.com/commerce/pro...roducts_id=705
They are inexpensive, easy to use, lots of example source code available, and the modules handle the transmission/reception. All you need to know is how to use SPI.
Good Luck
ctownsend >> Thanks a lot for your suggestion :)
One of the major causes to choose 433MHz is for the range. Initially I need ~500M area covered and I found no 2.4GHz or zigbee/802.11x to cover that range.
Another reason is the cost. I found xbee pro modules which support upto 1KM range with very good and stable datarate. But the price is >20S where as 433 MHz solutions come up <5 S. Advantage for volume production.
Do you know any reliable solution other than 433 MHz that supports ~500M range with stable datarate with protocols for data handling and error checking. Also <10S production level cost?
Maybe this will help, check this out:
http://www.laipac.com/easy_434a05W_eng.htm
They have a 0.5 Watt transmitter. Here is the datasheet.
Summitek http://www.summitek.com.tw have got a CC1100 based RF Transceiver with range upto 1KM. model: ST-TR1100+PA
Working with this was fun!.....no was able to open their cars with remote!