Sound Brick ver. 2

Right now I just found out that I have made a big mistake in Sound Brick ver. 2, since I used a wrong microcontroller. I misunderstand the usage of analog input in PIC16F628A, it just works as a analog comparator, not A/D converter. Since if I need to do the knocking part, I need to use the A/D converter to help me to convert the analog signal back to digital.So now, I will change the circuit design and the program code so that it can work with PIC16F685/689/690. By using PIC16F685/689/690 for my project, it also have advantages:

1. I can have more space for coding.
2. Have 8Mhz internal oscillator, can use higher serial communication speed.
3. Ram Bank arrangement is much better, 96+80+80 byte. I no need to afraid I can’t create three 50 elements byte array.
4. The price is almost the same as PIC16F628A.