how to get more memory location for ADC?

Discussion in 'Embedded Systems and Microcontrollers' started by meera, Aug 23, 2007.

  1. meera

    Thread Starter New Member

    Jun 7, 2007
    i m using PIC16F877.
    i had been ask to use potentiometer as analog input(0-5V) for PIC and display a range value(00.00-10.00) on LCD..

    may i know that is it for one analog signal input to PIC, there are only 256 location to store the convert result?
    since every port consist of 8 bits(mean 2^8)..
    10/256=0.04 mean that every location store differential value for 0.04?

    if i want to hv differential value less than 0.04, mean that i need to have memory location more than 256 place,then what should i do?
    for example, if i hv 500memory location, then one location will be 10/500=0.02 which is more precise..

    may i know what method can i use in order to get more memory location for store more data?

    is it by using external memory EEPROM??

  2. beenthere

    Retired Moderator

    Apr 20, 2004
    That is not the way the ADC works. Every time it converts, it outputs a word that is the digital value of the analog input. Just store the conversion value to one location and use that as the basis for your display. Since the display is 0 - 10 and the input is 0 - 5, you will need to double the value of the input word for the display.

    Increasing the ADC precision is not possible. How many bits does the ADC have? If it's 10 bits, then your conversion will be 10 bits in length. That would be one part in 1024.