基于嵌入式开发板FriendlyARM Mini6410开发板设计了一个电子琴,电子琴采用Qtopia软件编辑弹奏界面,通过对触模式液晶屏上按键控制脉冲宽度调制(Pulse Width Modulation,PWM)波形来演奏,LED灯相对应音符有7种闪烁方式,还能根据预置歌曲频率表音符的高音、低音、升调、降调、顿音、不发音来计算对应蜂鸣时间和停顿时间的PWM波形,播放预置歌曲.本设计用触摸屏代替了固体按键,增加了滑动条改变弹奏音符频率功能,运行稳定,控制系统可靠,软件功能完善,程序易于拓展.
Friendly ARM Mini 6410 is an ARM11 development board where the S3C6410 is used as the main processor,and it consists of an LCD (liquid crystal display) touch screen,one buzzer,and four LED (light emitting diode).The board is suitable for developing media players and other devices.An electronic organ is designed based on Friendly Arm Mini 6410 development board.The design uses the Qtopia software to realize graphical interface programming.The buttons on the LCD touch screen are used to control PWM (pulse width modulation) waveform and play songs with seven kinds of LED flashing modes.According to the music frequency table,the system can calculate the corresponding beep time and pause time of the PWM waveform to play the preset songs.This design uses a touch screen instead of solid buttons.The music frequency can be changed by the slider.The system is stable and easy to update.