AVR-Chat

I have found a couple of examples of interfacing an RF module with AVR
uC, but I was hoping to get a few more examples.

So far, I have:
www.uchobby.com/index.php/2007/05/01/simple-rf-wireless-link and
www.serasidis.gr/circuits/RF_remote-contol/RF_remote_control.htm

I have also come across DTVii also.

If anyone has any other resources that they can point me to, I would
appreciate it greatly.

> Interfacing to an RF module depends ENTIRELY on the RF module.

That is why I am searching for as many examples as I can.  I am trying
to determine what will be the best set up for me, to 'RC' some model
trains.

One of the links/devices that I listed uses a MAXIM232 to interface
between the RF module and the uC.  Some others that I have encountered
use a dedicated Manchester(?) IC.

Hi-

The second link is:
http://www.serasidis.gr/circuits/RF_remote_control/RF_remote_control.htm

David

Quoting Warpina Kezovitch <warp_kez@hotmail.com>:

> I have found a couple of examples of interfacing an RF module with AVR
> uC, but I was hoping to get a few more examples.
> 
> So far, I have:
> www.uchobby.com/index.php/2007/05/01/simple-rf-wireless-link and
> www.serasidis.gr/circuits/RF_remote-contol/RF_remote_control.htm
> 
> I have also come across DTVii also.
> 
> If anyone has any other resources that they can point me to, I would
> appreciate it greatly.
> 
> 
> 
>  
> Yahoo! Groups Links
> 
> 
> 
>

--- In AVR-Chat@yahoogroups.com, "Rene Teo" <rmteo@...> wrote:
>
> What gauge (scale) trains are you looking at?  I think size will be
a major
> consideration.

The gauge is often referred to as L gauge, but essentially Lego trains.

The conductive tracks were available, but there is a push for the
plastic ones, which more or less moots any DCC via the track.

--- In AVR-Chat@yahoogroups.com, James Wagner <wagnerj@...> wrote:
>
> You need to watch out because the term "RF module" covers a very big  
> range.
> 
> There are some very nice, and inexpensive ones from England (not  
> personally used) which I cannot find. There are also some inexpensive  
> ones sold by Laipac in Spain. The simplest are those that take plain  
> asynchronous serial to/from a UART. Many DO NOT need a MAX232.

There is a mob called Jaycar here in Australia that sells wireless
modules for $AU10 that operated at 433Mhz fixed.

Based on the couple of websites that I originally posted, and the
reference sheet for both the transmitter and the receiver, it looks
like the proverbial 'plug-n-play' arrangement.

Warpina -

Interfacing to an RF module depends ENTIRELY on the RF module. Some  
take an interface like SPI. Some take plain logic-level UART input/ 
output. Some take parallel data. Some take TWI. Some take other means.  
You need to define the RF module, first. Look at communication range,  
protocol (does the module provide some sort of protocol or is it all  
up to you), voltage levels, power consumption, operating frequency,  
antenna requirements, and such. Then, choose a module that will work  
with the processor of your choice, Or, if you can't find any, pick the  
module that inflicts the least pain. If you can't find any that do  
that, then you need to rethink your requirements.

Jim Wagner
Oregon Research Electronics
Tangent, OR, USA

On Jan 10, 2008, at 6:01 PM, Warpina Kezovitch wrote:

> I have found a couple of examples of interfacing an RF module with AVR
> uC, but I was hoping to get a few more examples.
>
> So far, I have:
> www.uchobby.com/index.php/2007/05/01/simple-rf-wireless-link and
> www.serasidis.gr/circuits/RF_remote-contol/RF_remote_control.htm
>
> I have also come across DTVii also.
>
> If anyone has any other resources that they can point me to, I would
> appreciate it greatly.
>
>
> 



[Non-text portions of this message have been removed]

You need to watch out because the term "RF module" covers a very big  
range.

There are some very nice, and inexpensive ones from England (not  
personally used) which I cannot find. There are also some inexpensive  
ones sold by Laipac in Spain. The simplest are those that take plain  
asynchronous serial to/from a UART. Many DO NOT need a MAX232.

Jim

On Jan 10, 2008, at 6:52 PM, Warpina Kezovitch wrote:

>
> > Interfacing to an RF module depends ENTIRELY on the RF module.
>
> That is why I am searching for as many examples as I can. I am trying
> to determine what will be the best set up for me, to 'RC' some model
> trains.
>
> One of the links/devices that I listed uses a MAXIM232 to interface
> between the RF module and the uC. Some others that I have encountered
> use a dedicated Manchester(?) IC.
>
>
> 



[Non-text portions of this message have been removed]

What gauge (scale) trains are you looking at?  I think size will be a major
consideration.

  ----- Original Message ----- 
  From: Warpina Kezovitch 
  To: AVR-Chat@yahoogroups.com 
  Sent: Thursday, January 10, 2008 7:52 PM
  Subject: [AVR-Chat] Re: Looking for some RF examples



  > Interfacing to an RF module depends ENTIRELY on the RF module.

  That is why I am searching for as many examples as I can. I am trying
  to determine what will be the best set up for me, to 'RC' some model
  trains.

  One of the links/devices that I listed uses a MAXIM232 to interface
  between the RF module and the uC. Some others that I have encountered
  use a dedicated Manchester(?) IC.



   

[Non-text portions of this message have been removed]

If that is the case, then you have wide choice of RF modules to choose
from.  If you were looking at something like HO (where the receiver has
to be about 0.65x1.00in.) then it would be a different story.

In any event, if size is not an issue, then one of the XBee modules from
Maxstream is a good choice. They are relatively inexpensive ($19-32 in
singles), widely available from several distributors and quite few people
have used them in radio control applications.  They use a simple serial
interface.  Size is about 0.96x1.1 or 0.96x1.3in. depending on the model.
http://www.digi.com/products/wireless/point-multipoint/xbee-pro-series1-module.jsp

  ----- Original Message ----- 
  From: Warpina Kezovitch 
  To: AVR-Chat@yahoogroups.com 
  Sent: Thursday, January 10, 2008 8:15 PM
  Subject: [AVR-Chat] Re: Looking for some RF examples


  --- In AVR-Chat@yahoogroups.com, "Rene Teo" <rmteo@...> wrote:
  >
  > What gauge (scale) trains are you looking at? I think size will be
  a major
  > consideration.

  The gauge is often referred to as L gauge, but essentially Lego trains.

  The conductive tracks were available, but there is a push for the
  plastic ones, which more or less moots any DCC via the track.



   

[Non-text portions of this message have been removed]

Sparkfun sells some EXTREMELY tiny modules with integral antenna, on
2.4 GHz, using Nordic NRF2401 chips.  I've done the AVR interface, and
once you get through configuring the chips, they work great.
Impressive range with simple antennas too.