LPC MicrocontrollersのトピックRe: COM UART debug on OM13285 board

COM UART debug on OM13285 board

sohanw — Mon, 09 Oct 2017 07:35:22 GMT

Hello,

I am trying to get the debug output working for OM13285 (https://www.nxp.com/docs/en/user-guide/UM10798.pdf) over the serial UART, with COM port connector on board.

Can anyone point me to an example which I can use to get this up and running? This is only for demonstration and test purposes so a quick way over the best way is preferred!

Thanks in advance!

Regards

Re: COM UART debug on OM13285 board

jeremyzhou — Tue, 10 Oct 2017 03:24:54 GMT

Hi Sohan Walimbe,

Thank you for your interest in NXP Semiconductor products and

the opportunity to serve you.

To provide the fastest possible support, I'd recommend you to refer to the rb_uart demo in the LPCXpreso LPC1343 board LPCOpen library: LPCOpen Software for LPC13XX|NXP

Have a great day,
TIC

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Re: COM UART debug on OM13285 board

sohanw — Tue, 10 Oct 2017 05:27:08 GMT

Hi jeremyzhou‌,

I tried the periph_uart_rb example but there is no output on COM port if I build it as it is. I don't have a debugger so I tried to toggle the on-board LED in the Systick_Handler, but that didn't work either.

Another example periph_i2c does toggle the LED in Systick_Handler, but still does not show any output on COM port. In fact the TXD line (PIO 0_7 on the board or pin 2 on the connector) seems to (coincidentally?) toggle at the same rate as the LED.

Note that I have enabled DEBUG_ENABLE and tried with or without NO_BOARD_LIB as well. Do I need to do any different clock and/or port mapping configurations for this specific board? I could not figure out anything different from the manual (https://www.nxp.com/docs/en/user-guide/UM10798.pdf).

Regards

Re: COM UART debug on OM13285 board

jeremyzhou — Wed, 11 Oct 2017 03:16:43 GMT

Hi Sohan Walimbe,

Thanks for your reply.

I'd highly recommend you to confirm whether the hardware configuration is correct or not, it's crucial.

Have a great day,
TIC

Re: COM UART debug on OM13285 board

sohanw — Wed, 11 Oct 2017 05:36:16 GMT

Hi jeremyzhou‌,

Nothing has been modified on the original OM13285 board. The schematic in the manual (https://www.nxp.com/docs/en/user-guide/UM10798.pdf ) is unchanged.

Regards

Re: COM UART debug on OM13285 board

jeremyzhou — Thu, 12 Oct 2017 10:02:48 GMT

Hi Sohan Walimbe,

Thanks for your reply.

After setting the DEBUG_ENABLE, the UART pins will be mapped via following codes.

And I think you need a debugger, and it would be better when having oscilloscope too.

   {(uint32_t)IOCON_PIO1_6,  (IOCON_FUNC1 | IOCON_RESERVED_BIT_6 | IOCON_RESERVED_BIT_7 | IOCON_MODE_INACT)}, /* PIO1_6 used for RXD */
    {(uint32_t)IOCON_PIO1_7,  (IOCON_FUNC1 | IOCON_RESERVED_BIT_6 | IOCON_RESERVED_BIT_7 | IOCON_MODE_INACT)}, /* PIO1_7 used for TXD */‍‍

Have a great day,
TIC

Re: COM UART debug on OM13285 board

sohanw — Wed, 01 Nov 2017 13:41:05 GMT

Hi jeremyzhou‌,

Thanks for your reply. After digging into it, I have found that the schematic of OM13285 has incorrect connection for UART TXD pin. So I removed the pin P0.7 on LPCXpresso LPC1343 board completely by desoldering. And connected the TXD pin to P0.7 from the bottom side of OM13285 PCB. This seems to work!

For future reference: The board OM13285 Rev 2.2 has this issue. NXP will possibly fix this in the future revisions.

Regards

Re: COM UART debug on OM13285 board

jeremyzhou — Thu, 02 Nov 2017 03:29:33 GMT

Hi Sohan Walimbe,

Thanks for your information, and I'll report this issue for the Document team for further checking.

Have a great day,
TIC

Re: COM UART debug on OM13285 board

sohanw — Thu, 02 Nov 2017 09:03:30 GMT

Hi jeremyzhou‌,

The documentation itself is correct, the schematic has incorrect connection of TXD pin. Perhaps you should report this to the circuit/PCB design team.

Regards

Re: COM UART debug on OM13285 board

jeremyzhou — Fri, 03 Nov 2017 02:05:44 GMT

Hi Sohan Walimbe,

Okay, I get it.
Have a great day,
TIC