RF Module Interfacing With Microcontroller

[amar]

Hello
i have to develop wireless remote for simple switching action(Relays) and distance rang minimum 100 meters i am using 8-Bit Microcontroller.
i have no idea about RF modules which one will be suitable for my application
i need reliable solution
please suggest me   

[dannyf]

i need reliable solution

A crystal oscillator modulated by your mcu. Easily several hundred meters.

[tszaboo]

I was using some HopeRF modules some years back, and with working auto-tuning, I was barely able to make it to 100m with a bigger 0.5W module. Of course a lot of stuff could have go wrong, but I suggest to use a bigger module, just in case. You can set the transmit power in some registers, so if you end up not needing it, no issues.

[TheDirty]

NRF24l01 are much more easily sourced and you can get one with PA + LNA easily as well.

E-Bay or DX are good sources.

[nessatse]

I found the standard (cheap) NRF24l01 modules don't have much range and will only reliably work if there is clear line of sight between the transmitter and receiver.  The ones with PA+LNA should perform better, but they are also considerably more expensive.  Recently I started playing the the NRF905, which is a 433/486/915MHz module and can push out 10mW.  I haven't really tested them for range yet, but they should perform much better.  The cheapest source I found is fasttech.com at $5.21 http://www.fasttech.com/products/0/10004905/1380701-nrf905-arduino-compatible-wireless-communication

[Jibby]

Refer the link

http://www.elprocus.com/remote-operated-robotic-vehicle-using-rf-module/

[Psi]

Sparkfun have some RF modules which can easy be connected to a MCU.
All the RF stuff is done for you. All you do is send data to it over the UART or SPI and you get the same UART/SPI data at the other end.

Sparkfun wont be the cheapest though, ebay will have cheaper modules,  but at least sparkfun provide example code and full module documenation.

[Clear as mud]

The cheapest source I found is fasttech.com at $5.21 http://www.fasttech.com/products/0/10004905/1380701-nrf905-arduino-compatible-wireless-communication

They don't know much about marketing, do they?  The device with the bent pin on the header, right next to a "QC passed" sticker, indicates to buyers that they don't care about quality.  Also that the one with only one bent pin must be the best one they ever made, since they used it for the item photographs.
  for the item photos, but for $5 I might try anyway and see if I get one without a bent pin.

[HackedFridgeMagnet]

I have been using HopeRF's RFM69H it works fine but has been a bit of a bitch to program.

I got decent range out of it, about least 100m, and it was running for a couple of weeks. But that is as far as I got with testing.

Only about $4 a module.

I was going to turn it down a bit too as I think it is slightly illegal at +20dbm. Never got around to it.

Hope RF modules are absolute rubbish.

Interested in what you say but it may be too late for me to change. Any further comment?




 

[nessatse]

They don't know much about marketing, do they?  The device with the bent pin on the header, right next to a "QC passed" sticker, indicates to buyers that they don't care about quality.  Also that the one with only one bent pin must be the best one they ever made, since they used it for the item photographs.
  for the item photos, but for $5 I might try anyway and see if I get one without a bent pin.

I suspect it is more a case of they have no idea what they are actually selling and the photographer probably thought the bent pin was normal.   Nonetheless, I have bought a few of these units from them, as well as various other bits and pieces and cannot say I have any problems with the actual products

[bookaboo]

Usually best to get a pre-approved radio module with most of the hard work already done. Radiometrix TX2 and RX2 are extremely reliable though you are best to write your own serial protocol for best performance. If you just stick rs232 in then it works, sort of but not optimal.
LPRS in the UK also do one called "Easy Radio" where the theory is that you just fire 9600 baud into the transmitter and it comes out at the receiver.

[geraldjhg]

hi there are some very good rf xtrc work at 9600 bd and easili interface
ill try and get on to you ASAP
saludos

[geraldjhg]

hi
here i found theese modules
http://www.tradeindia.com/fp1192809/Wireless-RF-Module-APC-200.html
ive worked with them here in arg some time ago
http://www.sycelectronica.com.ar/articulo.php?codigo=APC200
the pdf at this sight is bad but readable

they are very good but exp U$D
we made 50 portable landing lights for an airstrip that "talked " to one another
to turn on or off so as to reach the end of the airstrip

they work at 9600 bd, are transceivers and directly connectable to an mcu
the antennas are a problem as is the feedline
some that where left over i use them as a way of avoiding cables

saludos

[denizcan]

CC1101's are really nice.. With good antenna, @100m 250Kbits/sec is not an issue. @9600bits/sec you may go beyond that.. However, I don't think it is the easiest module to use.. NRF's are not as good as CC1101 but they are easier.. The easiest way would be the protocol handled by the module, line mentioned above..