How to read characters (string) in PSoC from Serial

Use an Rx interrupt, or poll, and fill an array byte by byte as they

are received. You would use a pointer into the array and inc it each

time you write a byte. There are example projects in Creator, on start

page "Find Example Projects" link.

Regards, Dana.

Are you trying to use the UART bridge that connects the USB interface to a (virtual) Com-port on your PC? Then you need to use the SCB - based component and connect Tx and Rx to Port4_0 and _1

When using a direct connection from your Tx and Rx pins P0_5 and _4 you will need a level shifter to convert the 5V signal to a +-12v RS232 level and back.

Bob

Maybe I misunderstood you, you are talking about " just wiring P0.4 and P0.5 to the Serial Bridge" which pins do you use?.

Did you confirm that the baud-rate for USB-chip is same as for your UART? Did you check using Cypress USB Configuration Utility?

Bob

Your variable "send" is defined too short, so sprintf() will overwrire data.

Declaring a local variable as "volatile" is of no use, it cannot get changed from the outside, but your variable "i" can.

Bob

´Concerning the "wiring": Sorry I was darn wrong with that. For the CY8CKIT-049-42xx prototyping kit P4_0 and P4_1 are correct.

No external wire needed, both pins are already connected to the USB-bridge. Just built and tested a project - attached.

Bob

I have a project that use "commands" to turn on the corresponding led on the RGB Led of the Pioneer Kit, i haven´t seen yours, but maybe it can help you, find it attached.

PD: en ese proyecto estaba tratando de entender las funciones de string.h asi que trae varias cosas que ni al caso xD

You are overdoing too much.

First the UART send:

Do not use delay functions, do not use UART_ClearTxBuffer() except in case of an error.

Instead use UART_ReadTxStatus() and check for completed transfer- Since UART_PutString is a blocking function not even that is needed.

Next the UART receive:

You do not need to use an interrupt, you may increase the Rx buffer in the UART component and look wit UART_GetRxBufferSize() for data received. Only difficulty is here to find out when a transmission is finished. Easiest is when a delimiter as \r or \n is received.

When using the interrupt the first thing in the handler is to clear the interrupt source using UART_ReadRxStatus().

Look into the UART's datasheet for explanations of the functions and the status registers.

What if you receive more than 5 bytes? Then you are destroying data!!!

You may, but you do not need to write your own conversion routines. There is the scanf() library routine which will do, have a look here.

Happy coding

Bob

You can also get the standard C puts, gets, scanf, printf stuff working with some pain

https://iotexpert.com/2017/05/10/implementing-psoc-printf/
Note: be sure to increase the heap size to at least 400 under Design Wide Resources, System, Configuration, Heap Size (bytes)

_read generally stolen from here. Assumes that an incoming 0 is nothing recieved (e.g. can't support binary data).

https://mcuoneclipse.com/2014/07/11/printf-and-scanf-with-gnu-arm-libraries/

#include "project.h"
#include "stdio.h"


//Replace the gcc default connectors for stdin and stdout
int _write(int file, char *ptr, int len) {
    int i;
    file = file;
    for (i = 0; i < len; i++) {
        UART_UartPutChar(*ptr++);
        }
    return len;
    }


int _read (int fd, const void *buf, size_t count) {
  size_t CharCnt = 0x00;
  (void)fd;                            /* Parameter is not used, suppress unused argument warning */
  for (;count > 0x00; --count) {
    /* Save character received by UARTx device into the receive buffer */
    while(!(*(uint8_t*)buf = (unsigned char)UART_UartGetChar()));
    CharCnt++;                         /* Increase char counter */
    /* Stop reading if CR (Ox0D) character is received */
    if (*(uint8_t*)buf == 0x0DU) {     /* New line character (CR) received ? */
      *(uint8_t*)buf = '\n';           /* Yes, convert LF to '\n' char. */
      break;                           /* Stop loop and return received char(s) */
    }
    buf++;                   /* Increase buffer pointer */
  }
  //return 1; /* WRONG! */
  return CharCnt;
}


//and now all the standard c io stuff works.
int main(void) {
    char buf[100]="";
    CyGlobalIntEnable; /* Enable global interrupts. */
    UART_Start();
    printf("Hello World\n\r");
    for(;;) {
//        char c = UART_UartGetChar();
//        UART_UartPutChar(toupper(c));
        //gets(buf); //bad idea. No size limit, no\r on input
        fgets(buf, sizeof(buf), stdin);
        for (int i=0;i<sizeof(buf) && buf[i];i++) {
            buf[i] = toupper(buf[i]);
            }
        printf(buf); //not secure
        }
}