Hello i am trying to compute my EFM32 Controller so it will send me at each clock cycle the number of LEDs that are ON.
I have tried to write the following code shown bellow.its very straight forward inside while(1)
i just increase variable "i" and depending on its value i send a char with that number(UART tx)
but in reality when i fetch in MATLAB what was recieved. Nothing recieved,no chars at all were sent.
Where did i go wrong?
Thanks.

#include "em_device.h"
#include "em_cmu.h"
#include "em_gpio.h"
#include "em_usart.h"
#include "em_chip.h"
#include <stdint.h>
#include <stdbool.h>
#include "em_emu.h"
#include "bsp.h"
#include "bsp_trace.h"
#define LED_PORT_E    gpioPortE
#define LED_PIN_E     15
#define LED_PORT_A    gpioPortA
#define LED_PIN_A     15



volatile uint32_t msTicks; /* counts 1ms timeTicks */

void Delay(uint32_t dlyTicks);
void SysTick_Handler(void)
{
  msTicks++;       /* increment counter necessary in Delay()*/
}
void Delay(uint32_t dlyTicks)
{
  uint32_t curTicks;

  curTicks = msTicks;
  while ((msTicks - curTicks) < dlyTicks) ;
}
int main(void)
{


  int i,j;
i=0;
  // Chip errata
  CHIP_Init();

  // Enable oscillator to GPIO and USART1 modules
  CMU_ClockEnable(cmuClock_GPIO, true);
  CMU_ClockEnable(cmuClock_USART1, true);
    if (SysTick_Config(CMU_ClockFreqGet(cmuClock_CORE) / 1000)) {
      while (1) ;
    }

    /* Initialize LED driver */

   // BSP_LedsInit();
  //  BSP_LedSet(0);
    GPIO_PinModeSet(LED_PORT_E,15,gpioModePushPull,1);
    GPIO_PinModeSet(LED_PORT_A,15,gpioModePushPull,1);

  // set pin modes for UART TX and RX pins
  GPIO_PinModeSet(gpioPortC, 1, gpioModeInput, 0);
  GPIO_PinModeSet(gpioPortC, 0, gpioModePushPull, 1);

// GPIO_PinModeSet(LED_PORT_A,15,gpioModePushPull,0);
  //GPIO_PinModeSet(LED_PORT_E,15,gpioModePushPull,0);

  // Initialize USART asynchronous mode and route pins
  USART_InitAsync_TypeDef init = USART_INITASYNC_DEFAULT;
  //init.parity=usartEvenParity;
  USART_InitAsync(USART1, &init);

  USART1->ROUTE |= USART_ROUTE_TXPEN | USART_ROUTE_RXPEN;



  while (1)
  {


      switch ( USART_Rx(USART1))
      {
           case 'h':

               GPIO_PinOutSet(LED_PORT_E,15);
               //USART_Tx(USART1,'G');USART_Tx(USART1,'R');USART_Tx(USART1,'E');USART_Tx(USART1,'E');USART_Tx(USART1,'N');USART_Tx(USART1,' ');USART_Tx(USART1,'O');USART_Tx(USART1,'F');USART_Tx(USART1,'F');USART_Tx(USART1,'\n');
                 i=i-1;
             // fprintf(USART1,"LED Green is off\n");
              break;
           case 'g':
               i=i+1;
              GPIO_PinOutClear(LED_PORT_E,15);
              USART_Tx(USART1,'G');USART_Tx(USART1,'R');USART_Tx(USART1,'E');USART_Tx(USART1,'E');USART_Tx(USART1,'N');USART_Tx(USART1,' ');USART_Tx(USART1,'O');USART_Tx(USART1,'N');USART_Tx(USART1,'\n');
              fprintf(USART1,"LED Green is ON\n");
          break;
           case 't':
               i=i-1;
               //GPIO_PinOutSet(LED_PORT_A,15);
               //USART_Tx(USART1,'R');USART_Tx(USART1,'E');USART_Tx(USART1,'D');USART_Tx(USART1,' ');USART_Tx(USART1,'O');USART_Tx(USART1,'F');USART_Tx(USART1,'F');USART_Tx(USART1,'\n');
               //fprintf(USART1,"LED RED is off\n");
           break;
           case 'r':
               i=i+1;
              //fprintf(USART1,"LED RED is ON\n");
               //USART_Tx(USART1,'R');USART_Tx(USART1,'E');USART_Tx(USART1,'D');USART_Tx(USART1,' ');USART_Tx(USART1,'O');USART_Tx(USART1,'N');USART_Tx(USART1,'\n');
               //GPIO_PinOutClear(LED_PORT_A,15);
              break;

           default:
               //fprintf(USART1,"NONE\n");
              // USART_Tx(USART1,'N');USART_Tx(USART1,'O');USART_Tx(USART1,'N');USART_Tx(USART1,'E');USART_Tx(USART1,'\n');
               break;
        
      }//end switch
      if(i==0)
      {
          USART_Tx(USART1,'0');
      }
      if(i==1)
            {
                USART_Tx(USART1,'1');
            }

      if(i==2)
                  {
                      USART_Tx(USART1,'2');
                  }


      }
  }

 

Add more if statements, that outputs a message like “OOR:lo”, if i<0 or “OOR:hi” if I>2.

if i is any other value other than 0-2, nothing will be sent. These statements will tell you why.

* “OOR” stands for out of range.