Buzz
If you're familiar with How CDs Work, you're already aware of the process behind storing sound digitally. A digital answering machine utilizes the same principles to convert a caller's message into a series of bytes. The microcontroller uses an analog-to-digital converter to digitize the caller's voice and stores it in low-energy RAM (random-access memory).
Suppose a caller records a 15-second message. This could be equivalent to 30,000 bytes of digitized data. These bytes are placed at a specific address within the RAM (refer to How C Programming Works for an explanation on memory addresses). When it's time to replay the message, the microcontroller retrieves the 30,000 bytes from RAM and plays them through a digital-to-analog converter.
RAM is a fast memory storage, so the microcontroller can delete one message and quickly shift other messages to fill the newly available space.
Here are some useful links:
- How CDs Function
- How Analog-Digital Recording Works
- How Telephones Operate
- Understanding RAM
- Understanding Bytes and Bits
- Fundamentals of Digital Recording
