//Arduino Uno, PWM output is possible on digital I/O pins 3, 5, 6, 9, 10 and 11.

#define pwmPinOutput 11

float voltageNeededToOutput = 1.798;
float analogPWMoutput = 0;
void setup() {
  Serial.begin(9600);
  pinMode(pwmPinOutput, OUTPUT);
}

void loop() {
  analogPWMoutput = map(voltageNeededToOutput, 0, 5, 0, 255);
  analogWrite(pwmPinOutput, analogPWMoutput);
}