Anyone here used Easy Radio wireless serial link?

They can be found here:

http://www.active-robots.com/product...nication.shtml

http://www.active-robots.com/product...-modules.shtml

Wondering any one used/use them?

Thanks.

 

Basically,

I got these from www.active-robots.com, they said what you put in is what you get at the other end, provided baud rate is 19200. The data sheet claims the output can be connected directly to a TTL/CMOS device.

The problem is this. The output from the receiving tranceiver is +/-10V for some reason. This makes it unsuitable to go into my 8051 uC. However, I can get over that using a potential divider.

The bigger problem is this. I checked using the oscilloscope the signal received and compared it with the signal trasmitted. Now, I thought what you put in is what you get at the output. But this wasnt the case. Although the bit stream was identical, the time I was not trasmitting, the logic was 0 (-10V) when it is meant to be a logic 1 according to what I was transmitting.

My computers Terminal/hyperterminal therefore could not make sense of the data, nor could my uC

I had the baud rate of 19200 set on everything.

Any shed of light would be appreciated.

 

im doing the same project !!!
well , i've got an RF Tx,RX from here in Egypt for 10$
i put a square wave , with 1khz , it was the same on the reciever but there's a propgation delay , i asked the professor he said its not a problem ...

you can contact me @ xgameprogrammer@hotmail.com =)

 

The datasheet says:

So the output from the receiver should be TTL/CMOS compatible, 0-3.3V or so. I suggest you consult Figure 11 and add a MAX232 if you want to feed directly to your PC.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Peace Ahmed,

Nice to meet you. Thanks for your email address.
All the best with your project.

Peace Nigel,

Well, the thing is the output is not 0-3.3V for some very weird reason. It shoots between -10V to +10V as if though it is meant to be for the RS232 port (when it should go through a MAX232). The datasheet says it should be between 0 and 3.3V, but its not so I cannot connect to CMOS/TTL devices.

I am very confused over this, and I did pay a lot of module for these transceiver modules, over £100. It doesnt seem as simple as they made it sound:

"To use these modules, simply connect them to a com port and using either your own software or Hyper terminal set to 19,200 baud, 8 data bits, 1 stop bit, no parity and no handshaking, then, whatever you type in one end will appear exactly the same at the other."

http://www.active-robots.com/product...re-radio.shtml

Maybe I am not understanding someting, but Im pretty sure I got it all covered.

Anyway, thanks very much for extending a helping hand.

 

Post a picture of how you have it connected, presumably you're doing something wrong somewhere?.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Ok, I will see what I can do.

Out of interest, have you ever used these devices?

Thanks.

 

Haven't used one but I have used packet radio in the past, the Easy radio modules have a 180 characters buffer. If you try to send too much this will cause trouble, but by the sound of it a 3.3V module outputting +\-10V is the real problem. If you have a RS232 port directly connected to the module you may have to start saving for a new one. See figure 11 in the http://www.active-robots.com/product....3-sept-05.pdf for the correct way. Are these modules or the evaluation kit?

 

No, but I have used plain radio modules, and unless you have a MAX232 they aren't going to output +/-10V.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

Hi Nigel, thanks.

Well, there is only threes pin to deal with. That is, Rx, Tx and GND as I am using the Transceiver module:

http://www.active-robots.com/product...re-radio.shtml

Looking at the bread board, I dont think it is worth taking the camera out, all it would appear to you is a mess of wires due to other devices on my bread board. Thanks for the idea.

I think Active Robots took these modules manufectured by LPRS and added on their own systems, soldered it onto their own PCB, which is why I only have 3 pins and not 9 like the datsheet says. And may be also why I am not getting the eoutput datasheet says.

peace.

 

You need to check the details from Active Robots then, it sounds like you may have a module designed to connect directly to a PC, so it has a TTL/RS232 interface on it.

__________________
PIC programmer software, and PIC Tutorials at:
http://www.winpicprog.co.uk

 

If you are using that module then , yes it is RS232. There may/should be a level converter chip on the board, you can take the signal before it is shifted.

 

You have bought modules made by active robots, 'using' the easy-radio modules

I'm sure those boards have a level shifter in them...I've used easy-radio products many many times..but I just bought the modules by themselves (the brass things). Those 'red' boards must have additional circuitry on them to provide +/-10v and it appears they power them with a 9v battery, when the modules themselves can only cope with 6V max - therefore, theres a regulator on board too.

I suggest you either cope with what you have..or desolder the easy-radio modules from that PCB...or buy some new easy radio modules direct from http://www.lprs.co.uk You'll be happy with the results...they really are little wonders!

Blueteeth

__________________
Inconsistency is the key to flexibility!

 

Thanks for the responses.

Blueteeth, I tried connecting to the PC directly as well as using max232, nothing.

I emailed active robots with the problem, see what they say tommorrow.

I really am disappointed with my purchase, it cost me over £100
And I only noticed the transceiver modules on its own today. I would have been better off with those and saved fifty quid.

Desoldering is not an option,too messy with little pin left. Active Robots have really done it this time, completely misleading customers with those data sheets. All the handshaking lines have been disabled too and the data sheet is irrelevant.

Can you tell me whether those modules on their own work without an external antenna? What is the range? And can you connect TTL/CMOS on input and on output directly? Do they need anything else to work? Thanks.

 

ace, do you remember the codes i need =) ?
thanks