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ADS7822P Object V2.0 - includes asm version for up to 100Ksps — Parallax Forums

ADS7822P Object V2.0 - includes asm version for up to 100Ksps

Bill HenningBill Henning Posts: 6,445
edited 2007-02-15 05:19 in Propeller 1
Actually up to about 140Ksps is possible if you use 6 bit conversion [noparse]:)[/noparse]

I've uploaded it into the object exchange, but until its approved there, you can grab it from my site (link below).

Both spin-only and asm versions are supported in the one object, however you can only use one mode at a time.

- Use the spin version if you need modest conversion speeds and save a cog
- Use the asm version if you need speed

V3.0 will add support for an 8:1 multiplexer

Best,

Bill


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www.mikronauts.com - a new blog about microcontrollers

Comments

  • Graham StablerGraham Stabler Posts: 2,507
    edited 2007-02-14 13:44
    Wow that's fast!

    Is it I2C?

    Thanks for posting

    Graham
  • bambinobambino Posts: 789
    edited 2007-02-14 16:43
    Bill,

    I ordered one of these and have yet to hook it up, but I'm curious.
    The manuel states 200Ksps Max. Is the speed your getting due to running it at 3.3V?
  • Bill HenningBill Henning Posts: 6,445
    edited 2007-02-15 05:14
    Well, its a pretty decent speed, faster than the A/D converter in a lot of microcontrollers [noparse]:)[/noparse]

    It's a simple 3-wire interface; essentially SPI

    You are most welcome!

    Bill
    Graham Stabler said...
    Wow that's fast!

    Is it I2C?

    Thanks for posting

    Graham
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    www.mikronauts.com - a new blog about microcontrollers
  • Bill HenningBill Henning Posts: 6,445
    edited 2007-02-15 05:19
    The data sheet I found stated 75khz max sampling rate, with a 1.2Mhz clock, however that was for the 2.7V low power part... I believe the 5V part is rated for 200khz at a 3MHz clock.

    After I posted the driver last night, I DID play around, going overspec... and I got it sampling at approx. 300ksps! Mind you, I don't know about the accuracy when overdriving it. I may try driving it at 5MHz just for kicks... using seven bit results that would get close to 500ksps, and six bit results would be slightly over 500ksps - assuming I don't fry the 7822!

    Best,

    Bill

    p.s.

    I'm chainging the sampling, I'll use TEST ..·wc / ADDX to eliminate another instruction [noparse]:)[/noparse]
    bambino said...

    Bill,

    I ordered one of these and have yet to hook it up, but I'm curious.
    The manuel states 200Ksps Max. Is the speed your getting due to running it at 3.3V?

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    www.mikronauts.com - a new blog about microcontrollers
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