Control

[YAN-1]

Hi there. I am interested in monitoring a couple of analog voltages in an embedded system and make calculations according to them. For example, I will monitor the speed of a motor coming as a voltage from a tachometer and compare it to the desired speed that is inputed to the PIC as a digital number. So my question is: the A/D converter in the 16F877 or any PIC having A/D modules can do the job, right? I don't have to use the comparator in the 'A' version of those PICs if I want to know the difference beween the actual speed and the desired one. I can just calibrate the different analog voltages first and store their digital eqivalants in a look-up table and then monitor the analog signal as it changes. Am I close?!

 

[Jay.slovak]

Hi there. I am interested in monitoring a couple of analog voltages in an embedded system and make calculations according to them. For example, I will monitor the speed of a motor coming as a voltage from a tachometer and compare it to the desired speed that is inputed to the PIC as a digital number. So my question is: the A/D converter in the 16F877 or any PIC having A/D modules can do the job, right? I don't have to use the comparator in the 'A' version of those PICs if I want to know the difference beween the actual speed and the desired one. I can just calibrate the different analog voltages first and store their digital eqivalants in a look-up table and then monitor the analog signal as it changes. Am I close?!

Yes, A/D with look-up tables will work fine here. Make sure you will use stable A/D voltage reference, and that tachometers impedance is not too high (may affect correct A/D result).