topic Re: Lpc11c24 uart in LPCXpresso IDE

Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:02 GMT

Content originally posted in LPCWare by urb4nm on Mon Feb 18 04:03:01 MST 2013
Hi,
I'm not-so-advanced in this kind of programming, and I've stumbled upon a minor problem.

I have to write a code for LPC11C24 to work with CO2 sensor using MODBUS protocol. No interrupts, just a simple write read sequence. I've got UART set correctly (done it before). What I need is to send a sequence, eg. {0xFE, 0x00,...} and read similar sequence back. I've tried to use something I've done before

void uart_send_byte(const uint8_t byte)
{
  while(!(LPC_UART->LSR & 0x20));
  LPC_UART->THR = byte;
}

for each byte of the sequence, but then it looks like there's nothing to receive. The thing is I don't know whether I messed up the sending, or receiving as I don't really know how to print output in console... This may sound like a noobish problem, and in fact it kind of is, but any help would be deeply appreciated...

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:03 GMT

Content originally posted in LPCWare by Ex-Zero on Mon Feb 18 04:38:03 MST 2013
What's wrong with ...\LPCXpresso_5.1.0_2048\lpcxpresso\Examples\NXP\LPC1000\LPC11xx\NXP_LPCXpresso11C24_2011-01-27.zip\uart sample :confused:

How do you receive :confused:

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:04 GMT

Content originally posted in LPCWare by urb4nm on Mon Feb 18 06:50:06 MST 2013
Well... There's nothing wrong I guess, it's just that I foolishly tried to rewrite the code I've already had... Then again thanks for pointing that out.. Nevertheless, I've tried to use that:

uint8_t uart_recv_byte(void) 
{ 
  while(!(LPC_UART->LSR & 0x01)); 
  return LPC_UART->RBR; 
}

And i just looped over nothing to read... And I'm still not sure if the console printout is working, any example for that would be great...

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:04 GMT

Content originally posted in LPCWare by Ex-Zero on Mon Feb 18 07:10:57 MST 2013
#1 Polling UART is not recommended :eek:

#2 What is 'console printout' :confused: Semihosting ? http://www.support.code-red-tech.com/CodeRedWiki/UsingPrintf

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:05 GMT

Content originally posted in LPCWare by urb4nm on Mon Feb 18 07:31:00 MST 2013
#1 I'm aware of that, but that's the way I was told to do... Besides, as you may noticed already, with my knowledge I'm in no position to question that... :(
#2 Yes, that's te thing... Been there, read that, tried using that even, it compiled, but since sending was not working, so I don't think I had a chance to try that... Can't show you how it looked though, I don't have access to it right now...

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:05 GMT

Content originally posted in LPCWare by Ex-Zero on Mon Feb 18 07:39:09 MST 2013
http://www.support.code-red-tech.com/CodeRedWiki/WhatIsSemiHosting

Quote:

Semihosting performance
It is fair to say that the semihosting mechanism does not provide a high performance i/o system.

And that's an understatement :eek: Semihosting is damned slow :eek::eek: So it is recommended to use a real UART :)

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:06 GMT

Content originally posted in LPCWare by urb4nm on Mon Feb 18 09:32:33 MST 2013
I see... It's just for debugging for now anyway...

How would an example receive and print functions look like?

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:06 GMT

Content originally posted in LPCWare by Ex-Zero on Mon Feb 18 10:05:49 MST 2013

Quote:
How would an example receive and print functions look like?

#1 Import working UART sample ...\LPCXpresso_5.1.0_2048\lpcxpresso\Examples\NXP\ LPC1000\LPC11xx\NXP_LPCXpresso11C24_2011-01-27.zip\uart :eek:

#2 Include <stdio.h> ;)

#3 Change Lib to Redlib (semihost) with 'Manage linker script' enable via Project Properties: http://www.support.code-red-tech.com/CodeRedWiki/SwitchingCLibrary

#4 Now you have a full working UART and can use printf() to print out data to your console (as far as you receive them slow enough) :):)

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:07 GMT

Content originally posted in LPCWare by urb4nm on Mon Feb 18 14:26:43 MST 2013
Thanks, I really appreciate your help, that would be great to start with :) I suppose it's not he end of problems for me, but then again I have to do something on my own :) I reckon it won't be the last post in this thread, but thanks again :)

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:08 GMT

Content originally posted in LPCWare by urb4nm on Tue Feb 19 05:46:21 MST 2013
So, I've imported stock UART example, as suggested, now, if I understand it correctly:

if ( UARTCount != 0 ) //if data in buffer
  {
    LPC_UART->IER = IER_THRE | IER_RLS;/* Disable RBR */
    UARTSend( (uint8_t *)UARTBuffer, UARTCount ); // echo data in buffer
    UARTCount = 0; //clear buffer
    LPC_UART->IER = IER_THRE | IER_RLS | IER_RBR;/* Re-enable RBR */
}

Or am I wrong somewhere? That means to send a command ({0xFE,..} ) and read back output I would need something like:

LPC_UART->IER = IER_THRE | IER_RLS;/* Disable RBR */
UARTSend( (uint8_t *)myTab, myTabLenght ); //send command 
LPC_UART->IER = IER_THRE | IER_RLS | IER_RBR;/* Re-enable RBR */

if ( UARTCount != 0 )
{
for(int i = 0, i < UARTCount, i++)
printf(UARTBuffer);

UARTCpunt = 0;
}

Does it make sense? It's just a general idea, but I need to know if it is at least good direction

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:08 GMT

Content originally posted in LPCWare by Ex-Zero on Tue Feb 19 06:00:09 MST 2013

Quote: urb4nm
Does it make sense?

Yes :) Could be useful to add a simple loop (about 1 sec) to repeat your transmission (and scope it or it's answer :eek: from your sensor) ;)

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:09 GMT

Content originally posted in LPCWare by urb4nm on Tue Feb 19 13:52:40 MST 2013
Well, I think it's getting too complicated for me...

When I try running debugging it stops on [B]UARTInit()[/B], calling the [B]HardFault_Handler()[/B] from [B]cr_startup_lpc11.c[/B], entering an infinite loop, not doing anything else. Second run gives me something like:

No source available for "(gdb[18].proc[42000].threadGroup[i1],gdb[18].proc[42000].OSthread[1]).thread[1].frame[0]"

but i guess it's just still looping...

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:09 GMT

Content originally posted in LPCWare by Ex-Zero on Tue Feb 19 14:03:17 MST 2013
:confused:

Try to close your GBD connection or just LPCXpresso.Reconnect LPC-Link and try it again. UART Sample is working without problems here. Is this original sample causing this problem or did you change it's code already?

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:10 GMT

Content originally posted in LPCWare by urb4nm on Tue Feb 19 14:53:36 MST 2013
Well, I've run sample, then again mine version, and it seems not to do that again.

I got printf(); working (it needed http://www.support.code-red-tech.com/CodeRedWiki/DebuggerSemihosting set manually), and as I feared there's still nothing to read back - UARTCount gets nothing, and it doesn't look promising...

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:10 GMT

Content originally posted in LPCWare by Ex-Zero on Tue Feb 19 15:09:41 MST 2013

Quote: urb4nm
...UARTCount gets nothing, and it doesn't look promising...

It's hardware time :) Scope your TxD / RxD and check your hardware ;)

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:11 GMT

Content originally posted in LPCWare by urb4nm on Tue Feb 19 15:43:32 MST 2013
Well, success! :)

I've got readout, the last problem was, as you predicted, hardware: 3.3V was not enough, I had to supply sensor with 5V and now it's working as supposed to. Polling works perfect, I get complete response, from this point I shoul be able to handle the rest by myself. Nevertheless, I'm very grateful for all your support and patience, it was a pleasure to be tutored by you :)

I reckon it's no the end of my problems, but for now I'd give it a break :)

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:12 GMT

Content originally posted in LPCWare by urb4nm on Thu Feb 21 13:39:42 MST 2013
It seems that I can't include [B]timer32.h[/B] to my project.
I've added [B]#include timer32.h[/B], added [B]#define CONFIG_ENABLE_DRIVER_TIMER32 1[/B], and I still can't call init_timer() and so on. [B]timer32.h[/B] is grayed out/crossed out under ./myproject/driver tree. Is there something I've missed?

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:12 GMT

Content originally posted in LPCWare by Ex-Zero on Thu Feb 21 13:49:43 MST 2013
Did you read #5 of http://knowledgebase.nxp.com/showthread.php?t=1684 already :confused:

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:13 GMT

Content originally posted in LPCWare by urb4nm on Thu Feb 21 15:00:40 MST 2013
Yes, but I tried the thing from #2 of the same topic, and succeeded, I think...

Why is that sometimes I run debugging I get some errors like:

No source available for  __sys_seek() at 0x28b6
No source available for "malloc() at 0x28be"

And so on?

Re: Lpc11c24 uart

lpcware — Wed, 15 Jun 2016 23:43:13 GMT

Content originally posted in LPCWare by Ex-Zero on Thu Feb 21 15:28:00 MST 2013
Are you trying to debug a library function (= compiled without debug information) ;) That's usually the cause for this message :)