Easy Radio problems, help needed!

AceOfHearts1 · Guest

Hi,

I bought two easy radio transcievers.

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. Basically, 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.

I had the baud rate of 19200 set on everything.

Help appreciated.

PS. I cannot communicate with the easy radio transcievers using the Easy Radio software, can any one help me on this?

amcfall · Joined: 20 Oct 2005 Posts: 44

Sounds like RS232 logic levels. Use a MAX232 or eq. and feed that into your micro.

Avery

Ttelmah · Guest

The question arises of what on earth this question is doing on this group. Hint, this is for _PIC_ microcontrollers, using the CCS C language.
See any mention of '8051' here.....

Best Wishes

rberek · Joined: 10 Jan 2005 Posts: 207 Location: Ottawa, Canada

Which Easy Radio receivers are you using exactly? And is this a module or have you designed the board that they are mounted on?

I looked at one Easy Radio datasheet, and it explicitly says that the serial data output is inverted, as you observed. As for the 10V output, these modules are meant to be powered bu 2.5-5 volts, with similar output levels. If you are measuring 10V at the receiver output, I'd suspect a wiring issue.

SherpaDoug · Joined: 07 Sep 2003 Posts: 1640 Location: Cape Cod Mass USA

You may find that the radio module uses a chip like the MAX232 at its output to get from TTL to RS232 levels. In that case you may be able to tap into the input pins of their MAX232 to extract the TTL level signals you need.

Look at the module output pin and see if you can follow the traces to the output chip. Then look up that chip to see what it does.

Of course the module maybe potted or the connections too small to work with in which case you are stuck. I have never seen the Easy Radio gear.
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