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RS232 STM8S-discovery

carnett1
Associate II
Posted on October 25, 2010 at 22:23

I have tried using0UM)884.  If I have the rs2323 disconnected from the PC i get an error.  I connect the rs232 cable it runs, but I don't get anything on my computer monitor. I put a breakpoint after the menu is supposed to be displayed but it doesn't display but i t does go through the routine to display the menu.  It stops on that break point.  I put a breakpoint after the getkey routine and it never getkey. I have found some minomers in UM0884.

Is there a trick or some error that I am unaware of?  Or anyone have any suggastions.

#i-am-sure-i-will-need-your-helpin-the-future-charles
4 REPLIES 4
Andrew Neil
Chief II
Posted on October 26, 2010 at 10:01

''I have tried using0UM)884.''

 

You mean, ''UM0884 User manual RS232 communications with HyperTerminal using the STM8S-DISCOVERY'' ?

http://www.st.com/stonline/products/literature/um/16898.pdf

What, exactly, do you mean by ''tried''?

Have you carefully followed all the instructions?

Are you sure that your RS2332 level converter circuit is working?

''If I have the rs2323 disconnected from the PC i get an error.''

 

What error do you get?

Where do you get it?

''I connect the rs232 cable it runs''

What runs?

''it does go through the routine to display the menu.  It stops on that break point.  I put a breakpoint after the getkey routine and it never getkey.''

 

What do you conclude from this?

Do you have an oscilloscope to check if there is any activity on the lines?

If you loop-back the PC's Tx to its Rx, does it work?

''I have found some minomers in UM0884.''

 

Such as what??

''Is there a trick or some error that I am unaware of?''

 

The trick to debugging anything is to proceed logically in a step-by-step process checking at each stage.

If something isn't working, ask yourself what could cause that.

Assume nothing - check & verify everything.

For debugging tips, see: 

http://www.8052.com/faqs/120313

 (not specific to 8052!)

Andrew Neil
Chief II
Posted on October 26, 2010 at 10:10

''anyone have any suggastions''

Something like this is invaluable for RS232 testing and debugging:

http://www.datalinkcom.net/accessories/9PMTT.html

http://uk.rs-online.com/web/search/searchBrowseAction.html?method=getProduct&R=6246347

http://www.bb-europe.com/product.asp?sku=9PMTT&TrailType=Sub&Trail=61

carnett1
Associate II
Posted on October 28, 2010 at 14:43

Andrew Neil
Chief II
Posted on October 28, 2010 at 15:32

Did the forum swallow your post then?