Hi, i'm currently doing a project related to home automation. i need to control relays with my 8051. for wireless communication i decided to use XBEE PRO but unfortunately i couldn't get it. can anyone tell me any alternative like RF module?? its number, range etc. please mention most common modules if you can... thanx.
You should pick a module that can be controlled by your 8051.
we had same project last year. we asked forum for rf module for 8051 everywhere but told none. not fast enough??? pic or arm is good.
that is my question that which one can be controlled by 8051??
i only need to send two bytes of data so speed is not an issue. i can use bluetooth as well if it can be interfaced with 8051 any cheap and common module?? i found linx LT series rf modules with 750m range. i wonder if i could use them.
... probably some others.
we had same project last year. we asked forum for rf module for 8051 everywhere but told none. not fast enough??? pic or arm is good. the fastest '51s are faster than the PICs and faster than many ARMs.
anyhow RF is not necessarily 'fast'
Erik
speed is not that much of an issue. if it can send 2 bytes in 1 or 2 sec m fine with it...
I would say that it is far easier for you to figure out which can not controlled by your mcu and go from there.
Because the universe of a modern RF data module that cannot be controlled by a mcu is far smaller than the universe of RF modules that can.
Any module that can work with PIC or ARM will (almost) certainly be able to work with an 8051!
Main thing to watch out for is USB-based modules - 8051 chips with USB host support isn't so common.
thanx guyz :). just last question. can any one name any common RF Module???
Yes.
Yes
then plz post the name dude :D
You are aware, that a common module in China need not be common in US? And "common" doesn't mean that it is a good choice for you.
You haven't even informed us about your exact range needs, and if you need a two-way link. Or if the module should be dumb and require addressing, validation, retransmission, ... handling by the processor or if the module should perform some or all of these things. Support for point-to-point or broadcast? 3.3V digital logic level? Or 5V? Or maybe RS-232 levels? Allowed frequency band to communicate on? One-off design or high-volume runs with availability important for many years? Single-frequency or wide-spectrum with some resilience to jamming in noisy environments? Energy-efficient for battery use? Built-in antenna or connector for external antenna? Possibility to power off transmitter while receiver still listens? Required supply voltage? Required temperature range? Special approvals? Frequencies etc configurable by software or hard-coded or unconfigurable?
okay i agree with low details thing. i need a power efficient module with 30m range at least better need 100m. point to point is optional i can use broadcast but if it comes there is no harm. RS-232 must be there as i need to hook up with 8051. frequency range is not my concern i only need acknowledgement mechanism and it should be handled by the module. XBEE PRO was my priority but i can have them due to unavailability of these modules in my region. can i have an alternative to it??? chip intena is preferable.
Interesting sentence: "RS-232 must be there as i need to hook up with 8051."
You mean that modules having a raw logic-level UART interface can't be used? Modules are normally not RS-232 if intended for connection directly to a microcontroller - RS-232 is normally for connecting to a PC or similar that have an _external_ serial port.
Next thing - there are modules that are using other interfaces, like SPI. They also work well with a 8051 chip.
If you have issues with getting XBee Pro modules in your region, then you should probably look for Bluetooth modules with RS-232 or logic-level UART interface. There are many other module types too, but an open issue then would be the frequency bands they use, in relation to the powers and frequencies allowed where you are. And many modules do not contain any acknowledge functionality.