I just received 2 XBee Pro modules. I have a standard RS232 output from a box and it looks like the XBee Pro needs a level converter (3.3vdc yuck) and the signal inverted for the DIN pin.

Does this look like it will work. Being it is wireless I have no idea how I will test it if it does not work. But my first shot.

My device has RTS/CTS as well, I am going to short them on the unit, the XBee-pro will not require it, but I put in pads for that as well.

Attached Images

new26.jpg (32.4 KB, 23 views)

 

The fact that it's wireless doesn't change how the level conversion works. Doesn't the voltage need to be regulated? I don't think dropping the extra 0.7V across the diode is going to work too well. I'm not sure about the data rates either, but the pull-up resistor might not allow it to be fast enough (not sure, but just saying).

How did you plan on sending data the other way? I'd just get an level converter IC for that, but usually when I need to convert something I need to convert a whole whack of pins.

 

The module has a 2.8 - 3.4VDC spec. So I thought I would try that as I have no 3.3 regulator or MAX3232.

The speed is 4800,8,n,1 and one way, so I thought I could get away with this. Once I install my "ideal" diode for protection

 

Anyone see why this will not work? RS232 out to an XBEE 3.3VDC module.

 

You shouldn’t have any issues with RS232, as its non-inverted, just as the example of xBee's here

As for the power supply, I wouldn’t lean toward the make-do circuit of yours, 3.3V regs are cheap. Search www.futurlec.com for LM1117T-3

They are 70c

I should note that the programming language for the above xBee example is Proton (I think, just had a quick browse of it)

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

xBee's are really over rated for most low-key projects, this little transceiver is packed with features
http://secure.oatleyelectronics.com/...roducts_id=388

* True single chip FSK transceiver 433MHz
* Few external components required
* No set up or configuration needed
* No coding of data required
* 20kbit/s data rate
* 2 channels
* Wide supply range
* Very low power consumption
* Standby mode
* Single +3 - 5V DC supply
* Transmit power can be adjusted to a maximum of 10dBm

And it costs $33 Australian, $26 US

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net

 

Yea, I saw this one.

The only problem again is a 3.3V regulator (for the remote side). I guess I will delay the project. My 4V battery and diode drop was for the remote station, but I still have the PC side to deal with. I do not want to use a microcontroller on the first project. It is an existing RS232 out to a PC.

I think they had a programming board, I might check that angle out as well. If $20US and here in 3 days..

Thanks for the info..

The 433Mhz unit I have a printout on my desk. Sometimes throwing in a PIC and AVR can make life simpler. Have you tried the 433Mhz unit, what indoor range did you get if so?

 

Not having tested the devices, only recommend by hear say, here’s what I found;

It would be less for indoors, probably only 20-30% of the totals above, but it would really depend on the environment

__________________
Spency.

PIC Micro's - Your mind is the limit

PIC's and interfacing with other devices - a PIC Basic Guide @ digital-diy.net