This design use MCU(AT89C51) as control core of the whole system. The efficiency of the driving loudspeaker used the triode whose model is TP122. This system can make the loudspeaker give out all kinds of tone exactly due to the signal----the pulse of every tone’s frequency. The system through all keystrokes, or the basis of the reliable hardware and the accurate and stable software, achieve the aim that broadcast all songs in turn or broadcast any song circularly. The digital display which have 7 LED can show song’s time any code, add into light—emitting diode twinkling make the design more perfect.
Key words: MCU, loudspeaker, keystroke, broadcast song