基于nRF2401 语音回放接收终端设计
The Design of nRF2401 Voice Playback Receiving Terminal
摘 要 设计了一套无线语音回放系统,利用STC12 单片机对语音信号进行数字化处理后,通过nRF2401 无线发送到接收端,接收端将数字信号通过D/A 转换成模拟信号,再经过带通滤波电路和功率放大电路输出。该系统采用驻极体对语音信号进行采集,用前置放大电路对微弱的语音信号进行放大,再通过300 Hz~3.4 kHz的带通滤波器滤除50 Hz 的市电影响和高频噪声,在一定程度上改善了语音回放的质量。
关键词 无线传输 语音 带通滤波 STC12 单片机
Abstract: This paper designs a wireless voice playback system, and after digitized the
voice signal with STC12 MCU, and sends them to receiving terminal through nRF2401
wireless. Receiving terminal changes the digital signal into an analog signal through the
D/A converter, and then outputs it through a band-pass filter circuit and power
amplification circuit. The system collect voice signals with electrets,and amplifying a weak
voice signals with preamplifier circuit,and then remove the impact of 50 Hz signal of city
power and high frequency noise with 300 Hz~3.4 kHz band-pass filter, and improve the
quality of voice playback to an extent.
Keywords: wireless transmission; speech; band-pass filter; STC12 MCU