27297 Parallax Inc, 27297 Datasheet - Page 121

• Manufacturer Part Number: 27297
• Description: KIT STAMPWORKS WITH BS2-IC
• Manufacturer: Parallax Inc

Specifications of 27297

• Lead Free Status: Contains lead
• Product: Microcontroller Accessories
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

front end of the PDB’s audio amplifier is a low-pass filter circuit that takes the pure
digital output (a special type of PWM output) from FREQOUT and smoothes it into a
nice sine wave that produces a clean musical note.
To see this in action, build the following circuit:
Using an oscilloscope, monitor the points marked “A” and “B” in the circuit while
running the following short program:
On a stock BS2 this will generate a 440 Hz tone for one second. Note the digital
output at point “A” and the sine-wave produced after the filter circuit at point “B”
(the 10 kΩ resistor represents the audio amplifier input).
Main:
FREQOUT Speaker, 1000, 440
GOTO Main