" 'analogWriteResolution()' was not declared in this scope " Error message

Hello, I am trying to half the output power of a motor control program I wrote a while ago which uses PWM pins. I wanted to do this by just changing the PWM resolution from 8 bits (255) to 9 bits (511) which should do the trick I would think, instead of going through the code and dividing everything by 2 or adding a function that does it before the outputs are applied. When I tried using the “analogWriteResolution()” command I got an error message saying " ‘analogWriteResolution()’ was not declared in this scope’ " this got me curious and I have been trying to solve the problem with no avail. I have included the code for the driver tester program I was going to use, with the error messages, as an example.

I am using an Arduino Mega 2560 Rev 3. It is not currently in my possession and so is not plugged in. I was just going to write a program and compile it then test it when I can, does this affect anything?

I tried using different versions of Arduino, 1.01 and 1.05 and both produce the same error messages.

I even tried adding ’ #include “Arduino.h” ’ but that did nothing.

I have tried searching for the answer on my own but I havent been able to find anything useful, so could you guys help me please?

#include "Arduino.h"

void setup(){

  for(int x = 0 ; x < 7; x++){
    pinMode(x, OUTPUT);


void loop(){
  analogWriteResolution(9);  //Change PWM resolution to 0-511
  int FULL_PIN = 2;      //Full power pin
  int HALF_PIN = 3;      //Half power pin
  int OSCI_PIN = 4;      //Oscilating pin (Triangular wave)
  int DIR_PIN  = 5;      //Direction pin (HIGH = reverse; LOW = forward)
  int HALF_POWER = 255;
  //Produce constant FULL and HALF power (using PWM) pins

  digitalWrite(FULL_PIN, HIGH);
  analogWrite(HALF_PIN, HALF_POWER);
[more code] 

Error Messages

Driver_tester2.ino: In function 'void loop()':
Driver_tester2:14: error 'analogWriteResolution' was not declared in this scope

‘analogWriteResolution()’ was not declared in this scope

The Due supports analogWriteResolution, wasn't aware any other Arduino did.

Find analogWriteResolution() on this page. Pay extra careful attention to what category it is under. Does that explain it?

Ah OK. I was aware the command existed but I wasnt aware it was only for the Due. That explains a lot. Thanks.

The fully Arduino compatible Teensy 3 and Teensy 3.1 boards also provide this. At 1/4 the size and for a lot less money 8)