tone() fails under 31Hz [imported]

[cmaglie]

This is Issue 558 moved from a Google Code project.
Added by 2011-06-10T14:31:23.000Z by adrianra...@gmail.com.
Please review that bug for more context and additional comments, but update this bug.

Original labels: Type-Defect, Priority-Medium

Original description

What steps will reproduce the problem?

1. Call tone(13,31). You will see a very fast blinking on the LED.
2. Call tone(13,30). You will see a seemingly continuously lit LED (it actually is a very high frequency blink).
   Any frequency below 31Hz will reproduce the problem.

What is the expected output? What do you see instead?
Expect to see the correct frequency, but a much higher one is seen instead (using an oscilloscope). Also observed on other digital pins.

What version of the Arduino software are you using? On what operating
system? Which Arduino board are you using?
Tried on Arduino UNO and Nano with ATMega328,
using Arduino 0022 on linux.

[per1234]

Although the limitation described in this issue still exists, it has since been documented (arduino/Arduino#1676 (comment)) on the tone() reference page, as requested in the Comment # 1 of the Google Code issue report.