topic Re: lpc55s16 USART data read related issue in LPC Microcontrollers

lpc55s16 USART data read related issue

firmwareteam — Mon, 03 Feb 2025 08:32:43 GMT

i am using lpc55s16 usart interrupt sample code .lpc55s16 next side another device transmit data in this code i can read 32 bytes and same time another 32 bytes data read 9times loop ran then full completed 258 byte data correct and i want to read more than 258 bytes read but at singles times loop.

attach screenshot(83) read data 32 byte and 9loop full completed .

data in 1 singel loop 258 byte data read?

screenshot singels 32 bytes data read ss

how to change in usart code.

usart data read function.

bool usart_Read(uint8_t* b) {

if ((kUSART_RxFifoNotEmptyFlag ) & USART_GetStatusFlags(USART1))

{

*b = USART_ReadByte(USART1);

return true;

}

else

{

return false;

}

9times loop ran then full completed 258 byte data.

case STEP_READ_LEN: /* Read length byte */

case STEP_READ_LEN:

if (usart_Read(&re->len)) {

return STEP_READ_DATA;

}

break;

case STEP_READ_DATA:

if (re->pos < re->len) {

if (usart_Read(&(re->data[re->pos]))) {

re->pos++;

}

Re: lpc55s16 USART data read related issue

Harry_Zhang — Wed, 05 Feb 2025 09:06:34 GMT

Hi @firmwareteam

If you want to read 258 bytes in a single loop iteration instead of 9 iterations of 32 bytes each, you need to modify your USART interrupt handling.

You can change the usart_Read.

int usart_Read(uint8_t* buf, int max_len) { int bytesRead = 0; while ((kUSART_RxFifoNotEmptyFlag) & USART_GetStatusFlags(USART1)) { if (bytesRead < max_len) { buf[bytesRead] = USART_ReadByte(USART1); bytesRead++; } else { break; // Stop reading if buffer is full } } return bytesRead; // Return the number of bytes read }

And you can update the STEP_READ_DATA case

case STEP_READ_DATA: if (re->pos < re->len) { int bytesReceived = usart_Read(&(re->data[re->pos]), re->len - re->pos); re->pos += bytesReceived; // If all 258 bytes are received in one loop, exit if (re->pos >= re->len) { return STEP_PROCESS_DATA; // Proceed to process data } } break;

Harry

Re: lpc55s16 USART data read related issue

firmwareteam — Wed, 05 Feb 2025 11:24:41 GMT

Hiii

update the STEP_READ_DATA case and change the usart_Read function.

same problem read data not change,32 bytes data read 9times loop ran then full completed 258 byte data.

Re: lpc55s16 USART data read related issue

Harry_Zhang — Mon, 10 Feb 2025 09:12:55 GMT

Hi @firmwareteam

May I ask if updating the code has resolved your issue?

Harry

Re: lpc55s16 USART data read related issue

firmwareteam — Mon, 10 Feb 2025 10:42:15 GMT

hii

updating the code not resolved issue.

same problem.

problem ask to second rplay.

Re: lpc55s16 USART data read related issue

Harry_Zhang — Wed, 12 Feb 2025 09:54:53 GMT

Hi @firmwareteam

To read more than 258 bytes in a single loop, I rewrote the relevant code.

#define DEMO_BUFFER_SIZE 512 #define DATA_TO_RECEIVE 258 ..... uint8_t rxBuffer[DEMO_BUFFER_SIZE]; volatile uint16_t rxCount = 0; volatile bool dataReceived = false; void DEMO_USART_IRQHandler(void) { uint8_t data; if ((kUSART_RxFifoNotEmptyFlag | kUSART_RxError) & USART_GetStatusFlags(DEMO_USART)) { data = USART_ReadByte(DEMO_USART); if (rxCount < DATA_TO_RECEIVE) // Store only up to the required amount { rxBuffer[rxCount++] = data; if (rxCount >= DATA_TO_RECEIVE) { dataReceived = true; // Signal that required data has been received } } } SDK_ISR_EXIT_BARRIER; } ..... int main(void) { .... while (1) { if (dataReceived) { /* Process received data */ USART_WriteBlocking(DEMO_USART, rxBuffer, rxCount); // Echo received data rxCount = 0; // Reset counter dataReceived = false; // Reset flag } } }

Harry