# UART\_access

**URL:** <https://forum.sierrawireless.com/t/uart-access/3957>\
**Category:** Open AT\
**Created:** [December 9, 2009, 12:41pm UTC](https://forum.sierrawireless.com/t/uart-access/3957 "2009-12-09T12:41:17Z")\
**Posts on this page:** 7\
**Page:** 1

<div class="post-metadata">

**Author:** ![sobrgsm](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@sobrgsm](https://forum.sierrawireless.com/u/sobrgsm)\
**Post date:** [December 9, 2009, 12:41pm UTC](https://forum.sierrawireless.com/t/uart-access/3957/1 "2009-12-09T12:41:17Z")

</div>

The command in UART1 does not open UART3 (USB)  
AT+WDU=1, “UART3”, 115200  
ERROR

AT+WMFM=0,0,3  
AT+WDU=1, “UART3”, 115200  
ERROR

AT+WMFM=0,1,3  
AT+WDU=1, “UART3”, 115200  
ERROR

The command in UART2 too does not open UART3 (USB)  
AT+WDU=1, “UART3”, 115200  
ERROR

AT+WMFM=0,0,3  
AT+WDU=1, “UART3”, 115200  
ERROR

AT+WMFM=0,1,3  
AT+WDU=1, “UART3”, 115200  
ERROR

What I not correctly do?

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<div class="post-metadata">

**Author:** ![davidc](https://avatars.discourse-cdn.com/v4/letter/d/a183cd/32.png) [@davidc](https://forum.sierrawireless.com/u/davidc)\
**Post date:** [December 9, 2009, 11:34pm UTC](https://forum.sierrawireless.com/t/uart-access/3957/2 "2009-12-09T23:34:56Z")

</div>

Hiya,

What version of the firmware are you using?

R7.4 opens the USB port automatically - this is a change from earlier firmware.

Try using AT+WMFM=0,2 to determine the state of all ports (see section 8.12.5 in the R7.4 AT Users Guide).

Also, turn on extended errors using AT+CMEE=1 to get more diagnostics than simply ‘ERROR’.

ciao, Dave

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<div class="post-metadata">

**Author:** ![sobrgsm](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@sobrgsm](https://forum.sierrawireless.com/u/sobrgsm)\
**Post date:** [December 10, 2009, 3:29am UTC](https://forum.sierrawireless.com/t/uart-access/3957/3 "2009-12-10T03:29:58Z")

</div>

version of the firmware R7.4a  
WMP100

at  
OK  
at+wmfm=0,2  
+WMFM: 0,2,1,1  
+WMFM: 0,2,2,1  
+WMFM: 0,2,3,0

OK

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<div class="post-metadata">

**Author:** ![sobrgsm](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@sobrgsm](https://forum.sierrawireless.com/u/sobrgsm)\
**Post date:** [December 10, 2009, 3:35am UTC](https://forum.sierrawireless.com/t/uart-access/3957/4 "2009-12-10T03:35:05Z")

</div>

at  
OK  
at+cmee=1  
OK  
at+wmfm?  
+WMFM: 0,2,1,1  
+WMFM: 0,2,2,1  
+WMFM: 0,2,3,0  
+WMFM: 1,2,4,0  
+WMFM: 1,2,4,1

OK  
at+wdu=1,“UART3”,115200  
ERROR

at+wmfm=0,0,2  
OK  
at  
OK  
at+wdu=1,“UART2”,9600  
OK

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<div class="post-metadata">

**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [December 10, 2009, 7:25am UTC](https://forum.sierrawireless.com/t/uart-access/3957/5 "2009-12-10T07:25:51Z")

</div>

AT+WDU is a custom command implemented by the sample; you have the source code - look at it to see what reasons could make it say, “ERROR”.

Debug it - add additional TRACE to see what’s going on…

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<div class="post-metadata">

**Author:** ![sobrgsm](https://avatars.discourse-cdn.com/v4/letter/s/df788c/32.png) [@sobrgsm](https://forum.sierrawireless.com/u/sobrgsm)\
**Post date:** [December 10, 2009, 8:36am UTC](https://forum.sierrawireless.com/t/uart-access/3957/6 "2009-12-10T08:36:26Z")

</div>

```auto
s32 uart_open( char* identity, u32 speed )
{
   s32 handle;
   sUartSettings_t Settings;
   psGItfCont_t pinterface;
   sUartEvent_t events;
   sUartLc_t lc;
   sUartFlowCtrl_t Fc;

   TRACE (( 1, "uart_open(UART%c,%d)",identity[4], speed ));
   /* Device */
   Settings.capabilities = NULL;
   Settings.identity = identity;
   Settings.role = UART_ROLE_NM;

   /* Events */
   events.user_data = (void*)0;
   events.valid_cb = UART_CB_ON_ALL;
   memcpy((u8*)events.cb_list, (u8*)uartCbTab, 6*sizeof(sGCbDesc_t));
   Settings.event_handlers = &events;

   /* To retrieve the UART SP Interface */
   Settings.interface = &pinterface;

   /* Line Coding */
   lc.valid_fields = UART_LC_ALL;
   lc.rate = (eUartRate_t)(UART_RATE_USER_DEF | speed );
   lc.stop = UART_STOP_BIT_1;
   lc.parity = UART_PARITY_NONE;
   lc.data = UART_DATALENGTH_8;

   Settings.line_coding = &lc;

   /*------------------*/
   /* open UART device */
   /*------------------*/
   if( 0 < (handle = adl_OpenDevice( DF_UART_CLID, &Settings)) )
   {
      TRACE(( 1, "UART successfully opened" ));

      /* Locally store the uart interface */
      uart_itf = *pinterface;

      /* Flow control IO control setting */
      Fc.op = G_IOC_OP_SET;
      Fc.type = UART_FC_RTS_CTS;

      if( uart_itf.io_control( handle, IOC_UART_FC, (void*) &Fc) )
      {
         uart_itf.close( handle );
         TRACE((1, "ERROR : IOCTL FC Set"));
         handle = 0;
      }
   }
   else
   {
      TRACE(( 1, "Uart_Open : ERROR UART is not opened" ));
   }
   return handle;
}
```

```auto

09/12/10,02:33:19:352	ADL	1	Binary header at 00260000
09/12/10,02:33:19:384	ADL	1	OK - mtInit
09/12/10,02:33:19:384	ADL	1	adl_atCmdSubscribe return 0
09/12/10,02:33:19:384	ADL	1	OK - stInit
09/12/10,02:33:19:384	ADL	1	Wait for a Received Data......
09/12/10,02:34:21:806	ADL	1	+WDU Command Handler
09/12/10,02:34:21:806	ADL	1	uart_open(UART3,115200)
09/12/10,02:34:21:806	ADL	1	Uart_Open : ERROR UART is not opened
```

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<div class="post-metadata">

**Author:** ![awneil](https://avatars.discourse-cdn.com/v4/letter/a/49beb7/32.png) [@awneil](https://forum.sierrawireless.com/u/awneil)\
**Post date:** [December 10, 2009, 9:49am UTC](https://forum.sierrawireless.com/t/uart-access/3957/7 "2009-12-10T09:49:01Z")

</div>

> [@awneil](#):
>
> Debug it - add additional TRACEs to see what’s going on…

Debugging is an essential part of all software development!

Some tips here: [8052.com/faqs/120313](http://www.8052.com/faqs/120313)

See also: [embedded.com/design/testissu … edded\_news](http://www.embedded.com/design/testissue/220100899?cid=RSSfeed_embedded_news)