UART terminal output scrambled using KL26Z64 and FT232RL

[gustavsl]

Hi. I am using KL26Z64 on a custom board without an external crystal, running at 41.94304MHz.

I'm using USBDM on a FRDM-KL25Z for programming and debugging.

I'm using UART (at 1310720 baud) to achieve serial communication using a FT232RL serial-to-USB converter.

I'm acquiring samples from a microphone using the ADC configured to 8-bit.

I'm converting the samples to output ASCII to a terminal.

The issue is that my data is randomly corrupted. For example, when the ADC reads a value of 94 or 95, it shows up on the Terminal as follows:

094
095
094
094
094
095
095
095
094
095
094
...

But randomly data shows up scrambled:

094
095
094
0
950094
095
095
094
...

I checked the clock settings and the timing for any interrupt starvation but that's not the case.

The code is as follows:

for(;;)
  {    
       LED1_On(); //LED on for time measuring
       AD1_Measure(TRUE);
       AD1_GetValue8(&leitura);
       // Converting to ASCII
       while (leitura >= 0 && i < 3)
       {   
            caractere = leitura % 10;
            charEnviar[i] = (caractere | mask);
            leitura = leitura / 10;
            i++;
       }
       // Send to terminal
       AS1_SendChar(charEnviar[2]);
       AS1_SendChar(charEnviar[1]);
       AS1_SendChar(charEnviar[0]);
       AS1_SendChar('\n');
       i = 0;
       LED1_Off();
  }

Thanks,

Gustavo.

[vicentegomez]

Hi Gustavo

probably the problem is the serial-to-USB converter. Have you check with the oscilloscope, if the signal from the Serial (kl26) is correct?

What happened if you only send data through the serial port? like only "test", did you see the same problem?

Regards

Vicente