Circuit Lake

Electronic Project and Circuit Collection

Digital Answering Machine, AVR AT90LS8535

06/20/2007 Category: AVR, Microcontroller, Miscellaneous, Project

This answering machine is built based on microcontroller AVR AT90LS8535. It can record up to our full 21 seconds and play it back in clearly understandable output. We can record anywhere from one 21.8 second message to thirtytwo .68 second messages. This leaves an incredible amount of flexibilty for an answering machine where message lengths vary unpredictably.

Answering Machine

Multiple messages are recorded one after another. Using the play button will begin with the first message and play until the end of the last message. The delete button will erase all of the messages at once (just like a cassette tape answering machine). The stop button will cease any playing and return to the beginning of the message queue. The skip button will cease the current message and begin playing the next message in the queue.

Project Features including : Recording will stop automatically if the end of the SRAM is reached preventing circular overwriting, Play will stop and end of last message preventing extra garbage from being played, Skip will not play beyond last message,Play and skip will not work if there are no messages present and Picking up the phone during play will cease play and start recording at end of message queue.