Due ADC Input = 0 - 3.3V (linear) Due DAC Output = 0.55 - 2.75V Linear

[due_noob]

Hello All

I was wondering if anyone could help me with an issue where I am sure I am missing something fundamental

I have two Arduinos connected to each other via a UART. The master has a potentiometer connected to its ADC input that varies the voltage between 0 - 3.3V. The 12-bit ADC value is sent to a slave via the UART that I was hoping would output a value on the DAC from 0.55V - 2.75V. The master and slave code can be seen below

Master

void setup()

{

Serial.begin(115200);		// initalize serial communication at 115200 bits per second

}

void loop()					//the loop routine runs over and over again forever: 

{

int sensorValue = analogRead(A0);	// read the input on analog pin 0:
Serial.println(sensorValue);
delay(30); 				 //delay in between reads for stability

}

Slave

void setup()

{
  Serial.begin(115200);
  analogWriteResolution(12);
  pinMode(DAC0, OUTPUT); 
}

void loop()
{
   if (Serial.available() > 0)
   {
      unsigned int val = Serial.parseInt();
      unsigned int ScaleVal = val*(2.2/4095);
      Serial.println(val);
      analogWrite(DAC0, ScaleVal);
   }
}

When this code is running the slave's serial monitor shows 0 for 0v on the master and 1023 for 3.3v on the master as I would expect. However on the slave's DAC output I just get 0.55V.

I am trying to make it such that for a liner increase of 0 - 3.3V on the master, will be a linear increase from 0.55V - 2.75 on the slaves DAC.

I am a bit stuck, can anyone help?

[due_noob]

If anyone needs to know, I have solved the problem.

I found that the default read and write resolution is NOT defaulted to 12 bits. Therefore I needed to define the read and write resolution for the master and slave. The correct code for the master and slave can be seen below

Master Source Code

void setup()
{
   // initalize serial communication at 9600 bits per second:
  Serial.begin(115200);
  analogReadResolution(12);
}

//the loop routine runs over and over again forever:

void loop() {
  // read the input on analog pin 0:
  unsigned int sensorValue = analogRead(A0);

  Serial.println(sensorValue);

  delay(30);  //delay in between reads for stability
}

Slave Source Code

void setup()
{
  Serial.begin(115200);
  analogWriteResolution(12);
  pinMode(DAC0, OUTPUT);
  
}

void loop()
{
   if (Serial.available() > 0)
   {
      unsigned int val = Serial.parseInt();
      Serial.println(val);
      analogWrite(DAC0, val);
   }
}

This gave be my linear relationship between master and slave where 0 - 3.3V on the master ADC input, corresponded to 0 - 2.75 on the slave DAC output.