We are running a survey to help us improve the experience for all of our members. If you see the survey appear, please take the time to tell us about your experience if you can.
I need to transmit a string of message between two Radio frequency transmitter. The message will be stored a microcontroller (e.g. 8051). How to go about writing a program for it and how to interface between the micrcontroller and the transmitters. I am still an amauteur when comes to embeded programming. Any source code or info on this ?
What do you mean by interfacing? Ther devices I listed earlier just transmit RS232 data over wireless. It is no different interfacing to these than it is to hook up your 8051 to a PC. Some of the higher end RF modules might require that you send it AT style commands (modem style) to initialize their baud rates, transmit power etc. So look up some data sheets, read some manuals and application notes. As for code samples...Code tends to be rather specific. Need more information.
Manoj, let's just clear a few things. First of all, I'm talking about RF Transceivers like the Aurel XTR-434, Radiometrix BiM2, RF Solutions RXQ1 etc. These modules operate at 433 MHz and some on 868 MHz. These are license-free modules, and it's range is limited to +/- 200m. These modules have a RX and TX, RX_ENABLE, TX_ENABLE, and CARRIER_DETECT. You have to write code to interface them properly! You still use the serial port to send and receive the data, but you have to manage the control signals as well. No problem, you save money and who's afraid of programming? Anyway, at some point modules differ. So you need to revise code. I'm trying to write some code for this modules, and simple RF transmitters, RF receivers, which can be re-used. This simplifies the development significantly. I don't know which model of Linx, or Maxstream you used, but let me know, and I'll check it out. Kind regards Christo v.d. Merwe
Hi Christo. My personal favorite wireless unit is from a company called MicroHard in Calgary. They make a 900MHz unit with up to 1 Watt of transmit power. http://www.microhardcorp.com/products_oem_compactrf.htm We just did some range tests with it and we can easily go a 1/2 Km at 0.1 Watt (line of sight). And we could probably go several Km with the proper antenna hardware at 1W. It is not cheap though...about 750$ a pair + Antennas. Have also used the Linx Wireless SC-PA but find it rather weak for what we do. It is however very low cost (30-50$ range) http://www.linxtechnologies.com/ldocs/pdfs/scpamanual.pdf Both these are license free and precertified (and therefore require no FCC certification). Will look at the Aurel part you are using.
Sorry for re-posting but I seriourly need help in interfacing two PIC by means of wireless RF data transfer. Anyone able to offer me help? Thks in advanced.
"but I seriourly need help in interfacing two PIC" Better find a PIC forum, then!
Clarence, here's a site which contains some very useful routines. It is written in C for a PIC compiler(CCS). Kind regards
Hi Manoj Do you have any circuit idea for transmitter/receiver module. Or any module available in India for hobby projets. Thanks
our teacher told us to search for a simple project that 8051 could be apply..just a simple projects that is not costly...affordable for the students can you give and example of this project?can you send me?
"our teacher told us to search ... can you send me?" Let's just read that again - who is supposed to be doing the searching: "our teacher told us to search" So off you go - get searching!
If you want a one-watt radio but don't want to pay the killer prices that some companies have to offer, check out MaxStream's new 9XTend. This wireless radio modem has a full one-watt of power (not pseudo-conducted one-watt trash like some other companies). This allows for up to four watts conducted output which is still allowable by the FCC without a license. MaxStream claims that you can get up to 40 miles of line-of-sight range with a high gain antenna. The development kit costs like $500, but since it is new the price will probably come down. Everything that I have read about this new radio sounds like MaxStream knows what they are doing. You can see their stuff at http://www.maxstream.net.