Go Down

Topic: Offset voltage on Arduino due DAC0 / DAC1 (Read 1 time) previous topic - next topic

dformenton

Hi,

with statement:

analogWrite(DAC0, 0);

instead of 0 volt output I find 0,540 volt. It seems as an offset voltage.

Is it normal? Is my Arduino damaged?

How I can avoid such offset to obtain output of 0 Volt with input value = 0?

Thank you

Domenico

Gericom


Hi,

with statement:

analogWrite(DAC0, 0);

instead of 0 volt output I find 0,540 volt. It seems as an offset voltage.

Is it normal? Is my Arduino damaged?

How I can avoid such offset to obtain output of 0 Volt with input value = 0?

Thank you

Domenico


Yes, that's normal.
Subscribe my youtube channel: http://www.youtube.com/user/MKDS3

masumi


HermannSW

OK, I did run into this issue as well and did measure complete curve, after having measured 0.5V/1.51V/2.41V on DAC1 when writing 0/2048/4095 to DAC1 with "analogWriteResolution(12)".

Then I used direct connection between DAC1 and A11, with just a cable and with a 1kΩ resistor.
The middle part of the curve is quite linear, but it does not start at 0 and does not end at 1023:


This is the small sketch used:
Code: [Select]
void setup() {
  pinMode(A10, INPUT);
  pinMode(DAC1, OUTPUT);
  analogWriteResolution(12);
  Serial.begin(9600);
}

void loop() {
  for(int i=0; i<4095; i+=100) {
    Serial.print(i);
    Serial.print(" ");
    analogWrite(DAC1, i);
    Serial.print(analogRead(A10));
    Serial.print(" ");
    delay(100);
    Serial.println(analogRead(A10));
  }
}


I plan to use one of DAC0-1 to one of A0-11 connection for playing with PID library.
First test on UNO with PWM showed that DAC is desirable for that.

Hermann.

Go Up
 


Please enter a valid email to subscribe

Confirm your email address

We need to confirm your email address.
To complete the subscription, please click the link in the email we just sent you.

Thank you for subscribing!

Arduino
via Egeo 16
Torino, 10131
Italy