topic How can I use UART0 of LPC4078? in LPC Microcontrollers

How can I use UART0 of LPC4078?

at-nakano — Sat, 21 Sep 2019 05:25:09 GMT

I do write a simple code to test UART0 of LPC4078 on our original board, but it does not work...

Codes for initialize UART0 are shown below:
void Uart0Init(void)
{
UART_CFG_Type UARTConfigStruct;
UART_FIFO_CFG_Type UARTFIFOConfigStruct;

UART_ConfigStructInit(&UARTConfigStruct);

UARTConfigStruct.Baud_rate = 115200;
UART_Init(UART_0, &UARTConfigStruct);

UART_FIFOConfigStructInit(&UARTFIFOConfigStruct);
UART_FIFOConfig(UART_0, &UARTFIFOConfigStruct);

UART_TxCmd(UART_0, ENABLE);

UART_IntConfig(UART_0, UART_INTCFG_RBR, ENABLE);

NVIC_SetPriority(UART0_IRQn, ((0x02<<3)|0x01));

NVIC_EnableIRQ(UART0_IRQn);
}
And the port 0.2 and 0.3 are set by codes below:
PINSEL_ConfigPin(0, 2, 1);
PINSEL_ConfigPin(0, 3, 1);

Based on the initialize code shown above, I tried to send some characters via ring buffer, but any characters sent to terminal.
I added "UART_SendByte(UART_0, 'A'); to simplify the debug work, but the result was same.

I believe "UART_SendByte" is very simple command and should be work, so there must be an error in my setup/initialization code...

The connection diagram of my debug environment are
PC USB
MCUXpresso ----- LPC-Link2 --------------- 4078board
Serial |
Tera Term ----- USB-Serial Converter ---------|

I did run the sample code "periph_uart_rb" and it was work, so I believe the hardware itself is correct.

Regards,

Re: How can I use UART0 of LPC4078?

Alice_Yang — Mon, 23 Sep 2019 08:35:26 GMT

Hello Atsuki Nakano,

Please check whether enable the UART clock and GPIO (UART TX/RX) clock.

You can refer to the UART demo under LPCopen for LPC4088:

LPCOpen Software for LPC40XX | NXP

Have a great day,
TIC

-------------------------------------------------------------------------------
Note:
- If this post answers your question, please click the "Mark Correct" button. Thank you!

- We are following threads for 7 weeks after the last post, later replies are ignored
Please open a new thread and refer to the closed one, if you have a related question at a later point in time.
-------------------------------------------------------------------------------

Re: How can I use UART0 of LPC4078?

at-nakano — Tue, 24 Sep 2019 08:00:53 GMT

Thank you Alice!

You mean, calling "Chip_Clock_EnablePeriphClock" from "Chip_UART_Init" in "uart_17xx_40xx.c"?
The "Chip_Clock_EnablePeriphClock" in "clock_17xx_40xx.c" and set the bit 3 of "LPC_SYSCTL->PCONP".
If so, "UART_Init" in "lpc_uart.c" calls "CLKPWR_ConfigPPWR" in "lpc_clkpwr.c" and certainly set the bit 3 of "LPC_SC->PCONP".
Finally, the value of "LPC_SC->PCONP" is "0x042887de", and the address of "LPC_SYSCTL->PCONP" and "LPC_SC->PCONP" is same, just "0x400fc000", so I think clock for UART is enabled.

Do you have any other idea or am I looking at the wrong place?

Regards,

Re: How can I use UART0 of LPC4078?

Alice_Yang — Wed, 25 Sep 2019 09:00:56 GMT

Hello Atsuki Nakano,

The easy way is compare your code with example code.

Or you can directly config based on the example, thus can save your time to development.

Alice

Re: How can I use UART0 of LPC4078?

at-nakano — Fri, 27 Sep 2019 00:18:52 GMT

Hi Alice,

Thank you for your support.

I'll look into the differences between sample code and my one again.

Regards,

Atsuki