topic Re: No UART transmission LPC1343 in LPC Microcontrollers

No UART transmission LPC1343

deboogle — Thu, 13 Jul 2017 14:01:37 GMT

I am trying to get the UART working on the LPC1343 at chip level and I have the PIO1_6 and PIO1_7 connected to an FTDI device which is plugged into my PC running putty. When I run the board level ring buffer example the UART is working and I see the output in putty, but when I try my chip level code, nada!

I created a project using the wizard and then added the following lines of code:

Chip_IOCON_PinMuxSet(LPC_IOCON,IOCON_PIO1_6,(IOCON_FUNC1 | IOCON_RESERVED_BIT_6 | IOCON_RESERVED_BIT_7 | IOCON_MODE_INACT));

Chip_IOCON_PinMuxSet(LPC_IOCON,IOCON_PIO1_7,(IOCON_FUNC1 | IOCON_RESERVED_BIT_6 | IOCON_RESERVED_BIT_7 | IOCON_MODE_INACT));

Chip_UART_Init(LPC_USART);
Chip_UART_SetBaud(LPC_USART, 115200);
Chip_UART_TXEnable(LPC_USART);

val = Chip_UART_Send(LPC_USART, "Test\n", 5);

after completion the returned value is 1 and i would have expected 5 as this is how many should have been placed into the buffer.

When I step through the code I can see the various characters being moved in but nothing is coming out of the terminal application?

Can anyone enlighten me as to what I have missed please? I am new to LPCopen having previously doen everything at register level using CMSIS only.

Re: No UART transmission LPC1343

kerryzhou — Fri, 14 Jul 2017 08:38:17 GMT

Hello David,

Please follow my step and try it on your side.

Please still modify the code based on the orignial periph_uart_rb code.

You can just call :val = Chip_UART_Send(LPC_USART, "Test\n", 5);

Then modify the Chip_UART_Send like this:

/* Transmit a byte array through the UART peripheral (non-blocking) */
int Chip_UART_Send(LPC_USART_T *pUART, const void *data, int numBytes)
{
int sent = 0;
uint8_t *p8 = (uint8_t *) data;

   /* Send until the transmit FIFO is full or out of bytes */
/*   while ((sent < numBytes) &&
           ((Chip_UART_ReadLineStatus(pUART) & UART_LSR_THRE) != 0)) {
       Chip_UART_SendByte(pUART, *p8);
       p8++;
       sent++;
   }*/

   while ((sent < numBytes) ) {
       while((Chip_UART_ReadLineStatus(pUART) & UART_LSR_THRE) == 0);
       Chip_UART_SendByte(pUART, *p8);
       p8++;
       sent++;
   }

return sent;
}

I have test it on my side, I can get the test printf data on my side:

My main code is:

int main(void)
{
   uint8_t key;
   int bytes;
   int val=0;
   /* Generic Initialization */
   SystemCoreClockUpdate();
   Board_Init();
   Init_UART_PinMux();
   Board_LED_Set(0, false);

   /* Setup UART for 115.2K8N1 */
   Chip_UART_Init(LPC_USART);
   Chip_UART_SetBaud(LPC_USART, 115200);
   Chip_UART_ConfigData(LPC_USART, (UART_LCR_WLEN8 | UART_LCR_SBS_1BIT));
   Chip_UART_SetupFIFOS(LPC_USART, (UART_FCR_FIFO_EN | UART_FCR_TRG_LEV2));//UART_FCR_TRG_LEV2
   Chip_UART_TXEnable(LPC_USART);

   /* Before using the ring buffers, initialize them using the ring
       buffer init function */
   RingBuffer_Init(&rxring, rxbuff, 1, UART_RRB_SIZE);
   RingBuffer_Init(&txring, txbuff, 1, UART_SRB_SIZE);

   /* Enable receive data and line status interrupt, the transmit interrupt
       is handled by the driver. */
   Chip_UART_IntEnable(LPC_USART, (UART_IER_RBRINT | UART_IER_RLSINT));

   /* preemption = 1, sub-priority = 1 */
   NVIC_SetPriority(UART0_IRQn, 1);
   NVIC_EnableIRQ(UART0_IRQn);

   /* Send initial messages */
//   Chip_UART_SendRB(LPC_USART, &txring, inst1, sizeof(inst1) - 1);
//   Chip_UART_SendRB(LPC_USART, &txring, inst2, sizeof(inst2) - 1);

val = Chip_UART_Send(LPC_USART, "Test\n", 5);

   /* Poll the receive ring buffer for the ESC (ASCII 27) key */
   key = 0;
   while (key != 27) {
       bytes = Chip_UART_ReadRB(LPC_USART, &rxring, &key, 1);
       if (bytes > 0) {
           /* Wrap value back around */
           if (Chip_UART_SendRB(LPC_USART, &txring, (const uint8_t *) &key, 1) != 1) {
               Board_LED_Toggle(0);/* Toggle LED if the TX FIFO is full */
           }
       }
   }

   /* DeInitialize UART0 peripheral */
   NVIC_DisableIRQ(UART0_IRQn);
   Chip_UART_DeInit(LPC_USART);

return 1;
}

Please try this at first, after it works on your side, then modify the chip initialization and test again.

Any question, please let me know!

Have a great day,
Kerry

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Re: No UART transmission LPC1343

deboogle — Tue, 18 Jul 2017 10:54:39 GMT

Hi Kerry,

The first thing I found was that I had not enabled the peripheral clock. Once I did that I found it only transmitted the first byte until I added the extra while statement as you suggested:

   while ((sent < numBytes) ) {
       while((Chip_UART_ReadLineStatus(pUART) & UART_LSR_THRE) == 0);
       Chip_UART_SendByte(pUART, *p8);
       p8++;
       sent++;
   }

return sent;
}

As obviously in its original incarnation will only send the first byte.

All working now many thanks.

Many thanks

Re: No UART transmission LPC1343

kerryzhou — Wed, 19 Jul 2017 08:48:47 GMT

Hello David,

You are welcome!

If your question is solved, please help me to close this post by marking the correct answer, thank you!

Have a great day,
Kerry