SUCCESS WITH A/D !!
I set up a circuit using one of my PIC microcontrollers to control an ADC0804LCN analog to digiital conversion chip. I measured the voltage on 2 AA batteries I had lying around. When I measured the batteries in series with my voltmeter, I got 2.81 volts. So after considerable circuit debugging and also debugging of my simple PIC program called ADPGM.ASM, I got the output which for the time was displayed in 8 LEDs. The output was as follows:
---MSB----------LSB
----1 0 0 1 0 0 0 1-----
In decimal that is 145. So:
-----145---- ---X-----
------------ = ---------------and X = 2.84
-----255--- ----5-----
Not bad ! My A/D chip can make a conversion in 100 usecs. So if I allow about 25 usecs for my computer pgm to store each sample voltage of an incoming signal, I could take 8000 samples a second !!!! Of course, my PIC program controls the number of samples I choose to take. I will be using this A/D converter to analyze speech and compare spoken words to some kind of template for comparing and identifying the words.
Posted by larrykeegan at July 25, 2005 09:40 PM