Basic Serout Problem

herold

I am using a simple program to output "Hello" in a loop (see attached program). Pin RB1 is connected to RX on the USB2SER chip. VCC is connected from the board to Vcc on teh USB2SER chip.

In my PC I am using the DDL driver to read the data. I am using the same Baud rate and connection settings but the data come in as unreadable characters.

I was testing a loopback with the USB2SER and the characters I send come exactly the same way back.

Is there anything I am missing here?

Jon Williams

I've attached my version of your program -- it takes advantage of SX/B features.· What you'll find is that SEROUT expands into a fair chunk of code, so embedding it into a subroutine is a good idea for saving money and giving you additional flexibility.· I used HyperTerminal to test and it worked first time.

Connections:
· RB.1 --> USB2SER.RX
· Vss· -->·USB2SER.VSS

Make sure you have the latest FTDI VCP drivers installed on your PC -- you need that for the USB2SER to work properly.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax

Post Edited (Jon Williams (Parallax)) : 7/28/2005 7:37:41 PM GMT

Jon Williams

Since I had everything hooked up I thought I'd share a teaser for version 1.4 (coming in a couple weeks) -- it will let you embed strings and trasmit them with farily-straightforward code.· The compiler takes care of generating the data for an inline string and addressing for both inline and strings stored in DATA statements.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax

herold

Hello Jon,

Thanks for the program. Well, with your program it works! And I found out why. It's the characters 13 & 10 on the end of the string Hello. Without them I get unreadable characters. Why do I need to send this characters?

What would I do to send random bytes to the serout? Would I send a string of 128 bytes and than end it with characters 13 & 10?

herold

Hello Jon,

Cool, just what I need. I use version 1.31 of the compiler but get lots of error messages. Do I have to wait until the new compiler comes out for using your program?

Is sending characters 13 & 10 after a string part of the serial protocol?

Post Edited (herold) : 7/28/2005 10:02:00 PM GMT

Jon Williams

I don't know what program you're having trouble with, so I can't explain why adding CR and LF to the end of the string is helping you. Had I not put those characters into my "Hello" program then it would have filled the screen without the linefeed in between.

You can't compile the strings program yet -- it requires 1.4 and only two of us have it. We're still testing.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax

herold

Hello Jon,

I used a simple test program to write "Hello" into the USB2SER and then read it again. I did this by making a loopback connecting RX & TX.

I may have to clearify this with the support of the FTDI people.

Jon Williams

Have a look at this thread: http://forums.parallax.com/showthread.php?p=541850

There is code within that exchanges data between a PC and the SX via the USB2SER adapter.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax

herold

Hello Jon,

Yes, of course this is my thread where everything started. But it doesn't work that way as Bean provided in his code as I am missing the 13&10 characters on each end.

I would have to send one byte and than 13&10 which is a waste of space. I guess I need to send packages of let's say 256 bytes and than send 13&10 to end this package.

Jon Williams

Well, as was determined in the other thread -- the problem is in your PC application.

▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
Jon Williams
Applications Engineer, Parallax