UART Comms Problem

That's what happens when one tries to reverse-engineer LynDoor™ equipment.

LynDoor™SureLock software is tamper proof, programer proof, compiler proof, and idiot proof.

It's not cat proof.

Did you switch the fax on? Maybe the receiving end is set to a slower baud rate?

Isn't RFID something new? Maybe use Cat Miau language instead of digital. Heck I think its a 64 bit system. The 8 bits wont fly.

But what do I know?

Are you using metric 1s and 0s or English?

If you can give the manufacturer's name and part number of the RFID module then others might find some fine print in the data sheet.

I assume you have good power for it. Is there a reset line and are there any reset specifications buried in the notes somewhere?

Might the module refuse to talk if it does not have a "connect" with a RFID tag? It seems a little dumb but it might be done as a power saving or anti-jabber feature.

Data sheet has been scoured and it's rather brief anyway.
Power is good.
It is detecting a tag ok, there's a 'tag present' LED on the board.
I've contacted the supplier asking for waveforms... dunno why they are not in the data sheet as a pic' is worth a thosand words.
I'll hang fire on the manufacturer unless they don't get back to me.
Del
I've been using 5v ones which I've had to saw down to 3.3 volt to fit into the input port.
The zeros seemed to fit ok

The RFID stuff we play with here ( mainly for door access ) is a bit touchy and it is usually the baud rate that is the problem, we have found you must do a complete computer restart every time you change the rate settings. I was dubious of this when I first had problems but it seems to have solved a lot of issues with lack of communications.

Cheers Glenn

Woo Hoo.
Got it fixed.

I got a reply from the supplier. The TX line needs to be high befor and after the data... I suspected this may be the case.
A simple screen shot from a scope included in the manual would have saved a lot of time.

Oddly, just inverting the whole data stream gave immediate success... I'm not going to start nit picking as to why... I shall put it down to the wrong flavour of '1's and just move on.

I'll prob stick to the slower baud rate too.

Del