FREQOUT Pin, Duration, Freq

Function
Generate square wave for a specified duration.

• Pin  is any SX IO pin (RA.0 .. RA.7, RB.0 .. RB.7, RC.0 .. RC.7, RD.0 .. RD.7, RE.0 .. RE.7).
• Duration  is a byte variable/constant (1 - 255) specifying the amount of time to generate the tone. The unit of time for Duration is 1 millisecond.
• Freq  is a constant (1 - 65535) specifying the frequency of the square wave.

Quick Facts

	Low Limit	High† Limit
Frequency	FREQ ÷ 500,000	FREQ ÷ 32

^† Note: For the greatest possible accuracy, limit high frequency value to FREQ ÷ 512.

Explanation
FREQOUT generates a square wave on an I/O pin. The output pin may be connected as shown in the circuits below for audio use. Other applications include IR LED modulation.

Note that the Duration can be affected by Freq parameter. For example, a frequency of 100 Hz has a period of 10 milliseconds, hence the shortest possible Duration value is 10. Even at this minimum, only one cycle would be produced and this may not be practical or useful.

When driving a Hi-Z speaker (> 40 Ω) or piezo element:

When connecting to an audio amplifier:

Related instruction: SOUND