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View Full Version : ADS7822P Object V2.0 - includes asm version for up to 100Ksps



Bill Henning
02-14-2007, 03:15 PM
Actually up to about 140Ksps is possible if you use 6 bit conversion :)

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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Graham Stabler
02-14-2007, 08:44 PM
Wow that's fast!

Is it I2C?

Thanks for posting

Graham

bambino
02-14-2007, 11:43 PM
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 Henning
02-15-2007, 12:14 PM
Well, its a pretty decent speed, faster than the A/D converter in a lot of microcontrollers :)

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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Bill Henning
02-15-2007, 12:19 PM
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 :)


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?



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www.mikronauts.com (http://www.mikronauts.com) - a new blog about microcontrollers