Serial Communication between ArduinoIDE and Simulink for controlling motor

Projects Programming
5

I am currently trying to control Arduino Uno with STM32L47RG in Simulink via UART. But I think Arduino Uno isn't receiving any of the data. The STM32's Rx and Tx pins are connected to the Arduino Uno's Rx and Tx.

The Arduino code I wrote is referenced from the Arduino Cookbook , the Serial Input Basics, and this example.
I have used an oscilloscope to check whether it is sending the data, and there is data being sent as shown in the image below. Can anyone help identify where I got wrong?

Simulink model:

simulink
simulink835×367 19.6 KB

Oscilloscope (sending the number 2 through UART):

osci_2
osci_21920×1440 223 KB

Arduino Code:

/*
 * SerialReceive sketch
 * Blink the LED at a rate proportional to the received digit value
*/
const int ledPin = 13; // pin the LED is connected to
int   blinkRate=0;     // blink rate stored in this variable

void setup()
{
  Serial.begin(115200); // Initialize serial port to send and receive at 9600 baud
  pinMode(ledPin, OUTPUT); // set this pin as output
}

void loop()
{
  if ( Serial.available()) // Check to see if at least one character is available
  {
    char ch = Serial.read();
    if(ch >= '0' && ch <= '9') // is this an ascii digit between 0 and 9?
    {
       blinkRate = (ch - '0');      // ASCII value converted to numeric value
       blinkRate = blinkRate * 100; // actual blinkrate is 100 mS times received digit
    }
  }
  blink();
}

// blink the LED with the on and off times determined by blinkRate
void blink()
{
  digitalWrite(ledPin,HIGH);
  delay(blinkRate); // delay depends on blinkrate value
  digitalWrite(ledPin,LOW);
  delay(blinkRate);
}