Post by thread:[PIC]:UART problem

Does anyone have any example "C" code for Interrupt driven TX routine using UART ? I have looked at piclist.com and cannot find what I need there. I can get the TX started but it will not stop. I tried using TXEN to stop it, but then it reconfigures the port to hi-Z. Currently I initiate transmission by loading TXREG with 1st data byte from tx_buffer[0] and inc tx_ptr to 1. Next I set TXIE to true. In the interrupt routine I poll (TXIF & TXIE) Each time a byte is sent, I inc TX_Ptr and when all is sent I disable TXIE. If I enable TXIE and load TXREG, the uart sends for a while and results in stack overflow. If I do not set TXIE, it transmits forever even though it never gets to the int routine. -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

On Tue, Mar 06, 2001 at 01:55:47PM +1100, David Huisman wrote: > I can get the TX started but it will not stop. From my understanding of the UART on PIC 16F877 at least, the only way to get this situation is to keep loading TXREG. Assuming asynchronous mode. You are clearing SYNC or setting it? I think you should offer your code for review. -- James Cameron spam_OUTquozlTakeThisOuTus.netrek.org http://quozl.netrek.org/ -- http://www.piclist.com hint: The PICList is archived three different ways. See http://www.piclist.com/#archives for details.

David Huisman wrote: >Does anyone have any example "C" code for Interrupt driven TX routine using >UART >? I have looked at piclist.com and cannot find what I need there. > >I can get the TX started but it will not stop. > Does this mean it keeps transmitting the "same" data over and over, or different data? ============= > >Currently I initiate transmission by loading TXREG with 1st data byte from >tx_buffer[0] and inc tx_ptr to 1. >Next I set TXIE to true. > And of course, you did clear TXIF? ======== >In the interrupt routine I poll (TXIF & TXIE) >Each time a byte is sent, I inc TX_Ptr and when all is sent I disable TXIE. > And clear TXIF? ========= >If I enable TXIE and load TXREG, the uart sends for a while and results in >stack overflow. Return stack? or a s.w. stack you created? If the former, then it sounds like you are not returning from interrupt properly. =========== >If I do not set TXIE, it transmits forever even though it never gets to the >int routine. > You do know that you can use the UART for transmitting, without using interrupts? Just wait for TXIF to be clear, and then load TXREG. -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservKILLspam@spam@mitvma.mit.edu with SET PICList DIGEST in the body

Hmmm. I think I have found your problem. You need some code. Fr. Tom McGahee ----- Original Message ----- From: David Huisman <david.huismanKILLspamADVMININGTECH.COM.AU> To: <.....PICLISTKILLspam.....MITVMA.MIT.EDU> Sent: Monday, March 05, 2001 11:00 PM Subject: Re: [PIC]:UART problem {Quote hidden}> James, > > Here is code for review. > > Regards > > David Huisman > > -- > http://www.piclist.com hint: The PICList is archived three different > ways. See http://www.piclist.com/#archives for details. > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email EraseMElistservspam_OUTTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Thomas, You are right :) I will re-post with attachment this time :) Best Regards David Huisman ---------------------------------------------------------------- Orbit Communications Reliable RF data modules,wireless telemetry rfic and other communication solutions Web site: http://www.orbitcoms.com Email: infospam_OUTorbitcoms.com PO Box 3459, Tuggerah, NSW 2259, Australia Phone:+61-2-4329-7765 Fax:+61-2-4329-7893 Mobile (within Australia): +61-0412-566-629 Mobile (International): +61-412-566-629 {Original Message removed}

must be vaporware..... ;-) -----Original Message----- From: David Huisman [KILLspamdavid.huismanKILLspamADVMININGTECH.COM.AU] Sent: Tuesday, March 06, 2001 1:42 PM To: RemoveMEPICLISTTakeThisOuTMITVMA.MIT.EDU Subject: Re: [PIC]:UART problem Here is the code that should have been attached yesterday. Regards David Huisman -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spamBeGonelistservspamBeGonemitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email TakeThisOuTlistservEraseMEspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body

At 08:42 AM 3/7/01 +1100, David Huisman wrote: >Here is the code that should have been attached yesterday. > >Regards Here we see RISC code, taken to it's logical limit. It takes no space, executes infinitely fast, yet accomplishes nothing. :) -- Dave's Engineering Page: http://www.dvanhorn.org Where's dave? http://www.findu.com/cgi-bin/find.cgi?kc6ete-9 -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservTakeThisOuTmitvma.mit.edu with SET PICList DIGEST in the body

Hmmmm. You seem to still have the same problem: no code. Fr. Tom McGahee ----- Original Message ----- From: David Huisman <david.huismanEraseME.....ADVMININGTECH.COM.AU> To: <EraseMEPICLISTMITVMA.MIT.EDU> Sent: Tuesday, March 06, 2001 4:42 PM Subject: Re: [PIC]:UART problem {Quote hidden}> Here is the code that should have been attached yesterday. > > Regards > > > David Huisman > > -- > http://www.piclist.com#nomail Going offline? Don't AutoReply us! > email RemoveMElistservEraseMEEraseMEmitvma.mit.edu with SET PICList DIGEST in the body > > -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservspam_OUTKILLspammitvma.mit.edu with SET PICList DIGEST in the body

The code was sent as attachments. Do I need to cut and paste code into email itself ? Regards David Huisman -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email RemoveMElistservTakeThisOuTspammitvma.mit.edu with SET PICList DIGEST in the body

It doesn't seem to make it to the list. Try sending it to yourself and see what happens. -----Original Message----- From: David Huisman [EraseMEdavid.huismanspamspamBeGoneADVMININGTECH.COM.AU] Sent: Tuesday, March 06, 2001 4:08 PM To: RemoveMEPICLISTKILLspamMITVMA.MIT.EDU Subject: Re: [PIC]:UART problem The code was sent as attachments. Do I need to cut and paste code into email itself ? Regards David Huisman -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email listservSTOPspamspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email spamBeGonelistservSTOPspamEraseMEmitvma.mit.edu with SET PICList DIGEST in the body

There is a limit on the size of an attachment sent to this list. You are welcome to post it to piclist.com and then reference it from there. James Newton, PICList Admin #3 KILLspamjamesnewtonspamBeGonepiclist.com 1-619-652-0593 phone http://www.piclist.com ----- Original Message ----- From: Sam Linder <EraseMESamLEraseMEIN-INC.COM> To: <@spam@PICLIST@spam@spam_OUTMITVMA.MIT.EDU> Sent: Tuesday, March 06, 2001 16:58 Subject: Re: [PIC]:UART problem It doesn't seem to make it to the list. Try sending it to yourself and see what happens. {Original Message removed}

On Wed, Mar 07, 2001 at 11:08:29AM +1100, David Huisman wrote: > The code was sent as attachments. Do I need to cut and paste code into > email itself ? Yes, the list server must be dropping your large file. I received it fine bypassing the list when you sent it to me. Probably best to reduce the code into the essential components rather than post the whole source file. I'm afraid I couldn't find anything wrong with your code, except what I mentioned, but I didn't think that should have caused the problem. If you do find out what the cause was, please let me know. -- James Cameron spamBeGonequozlKILLspamus.netrek.org http://quozl.netrek.org/ -- http://www.piclist.com#nomail Going offline? Don't AutoReply us! email .....listservspam_OUTmitvma.mit.edu with SET PICList DIGEST in the body