Shop OBEX P1 Docs P2 Docs Learn Events
16+ Bit Counter Based ADC — Parallax Forums

16+ Bit Counter Based ADC

TJHJTJHJ Posts: 243
edited 2008-07-21 18:34 in Propeller 1
So I was wondering has anyone tried or know if you can use 16 or greater bit ADC conversion using the counter system to convert it. Under the Counters doc it gives an example but only shows up to 14bit. I was unsure if there was a hidden reason for this or just the longer sampling time to achieve it.

I was wondering if it would still work if you just placed 16 in the changeable value under the ADC example?

If anyone knows please let me know.

Thank you for your time.
TJ

Comments

  • Mike GreenMike Green Posts: 23,101
    edited 2008-07-20 20:18
    You could certainly use 16 or greater and the routines would operate, but you wouldn't get the better accuracy. I very much doubt if you could really get 14 bit accuracy without very careful attention to noise, PCB layout, and choice of I/O pins involved. Try it. Use a known fixed voltage reference and plot values over time with various bit counts.

    If you want high accuracy, you really have to use an external ADC chip, one designed to give the accuracy you want. Most general purpose chips will only provide up to 12 bits and that's hard enough to get without careful design.
  • TJHJTJHJ Posts: 243
    edited 2008-07-21 18:02
    Yeah, I'm reading thermocouples and was trying to get away with out using op amps. To easy I guess. Would the counter as a 12 bit be as acurrate as a external 12 bit ADC chip?
  • Mike GreenMike Green Posts: 23,101
    edited 2008-07-21 18:34
    No
Sign In or Register to comment.