3.b.7. Command 226: Set Volume
Effect: Sets the buzzer volume by affecting the duty cycle of the PWM sent to the buzzer. The formula used is duty cycle = TOP >> (16 – volume), where 0 <= volume <= 15. A max volume of 15 produces a 50% duty cycle. A minimum volume of 0 produces a 0% duty cycle (however even at a duty cycle of 0% the buzzer pwm will go high for one timer count every period, thereby introducing some switching noise to your system).
This value can be saved to byte 17 of EEPROM using command 240 (Section 3.d.02) so that it will persist after a hardware reset. When storing in EEPROM, you must ensure the value is within the volume’s allowed range of 0 – 15.
Values sent: volume (4 bits)
command byte = 226
data byte = 4-bit volume (bits 4 – 6 are ignored)