There are so many devices available which can record and playback voice. Most of the digital devices like mobile phones can use the SD card to record the voice signals and playback. This project demonstrates how to record voice signals on a micro SD card and play it back using the GR SAKURA board. Voice signals are continuous analog signals and the digital devices like microcontrollers cannot handle the continuous analog signals. Most of the microcontrollers have an ADC module which can do analog to digital conversion. The microcontroller uses sampling technique to convert the continuous analog signals to discrete digital equivalent samples. While recording the voice, the GR SAKURA board samples the voice signals and writes the sampled values to a file at the sampling time itself. The same file is opened again and reads the values at the same frequency at which they are sampled.
Talking Parrot using GR Sakura
This is a very interesting and funny project made with the help of the GR SAKURA board which can record the speech and play it back in the voice of a parrot. It might look like a toy but there are lot of technology behind its working like voice sampling, memory card interfacing, PWM etc. Voice signals are continuous analog signals and the digital devices like microcontrollers cannot handle the continuous analog signals. Most of the microcontrollers have an ADC module which can do analog to digital conversion. The microcontroller uses sampling technique to convert the continuous analog signals to discrete digital equivalent samples. While recording the voice, the GR SAKURA board samples the voice signals and writes the sampled values to a file at the sampling time itself.
Voice Sampling and PWM Reproduction by GR Sakura
Voice signals are continuous analog signals and the analog circuits or systems can only handle the voice signals without changing their continuity feature. There come situations in which the analog voice signals need to be applied as the input to simple digital microcontrollers. The digital devices like microcontrollers cannot handle the continuous analog signals. Most of the microcontrollers have an ADC module which can do analog to digital conversion. The microcontroller uses sampling technique to convert the continuous analog signals to discrete digital equivalent samples. The digital microcontrollers based devices cannot produce analog output also, since their output will be always either logic high or logic low. To generate the effect of the continuous analog signal at any output device connected to the microcontroller, they use a technique called PWM (Pulse Width Modulation). In this project the sampling and reproduction of voice signal is demonstrated with the help of GR SAKURA board.