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Subject: Re: I2C bus for expansion

From: "djbrow54" <davebr@...>
Date: 2006-03-29

--- In ComputerVoltageSources@yahoogroups.com, "John Loffink"
<jloffink@...> wrote:
>
> Do we have to pay for your DPO4000 too? That will be one expensive
> piece of code. :-)

You know, this scope is quite affordable. But no, I've just borrowed
it for now.

I did manage to interface the AtomPro24 I2C to a SAA1064 I2C to 7
segment LED driver. I am sending 6 data bytes in a single message (7
bytes total since it includes the device address byte) in 1.32 mS.
The receiver is correctly ack'ing the packets and I am not getting any
AtomPro24 errors.

With interrupts enabled at 1 mS timer, I can see the packets jitter as
the cycles are stretched by the interrupt service routine. It all
seems to work quite well (as long as you used a scope to figure out
the peculiarities of the i2cout command).

The burst data transfer is 4545 bytes/second. Now that I have a known
data stream, I will see if I can get an AVR to correctly receive it.
I'm not going to do anything until my LCD arrives and I can verify
functionality of my code. I don't want to tear the development system
down yet. The LCD is scheduled to arrive Monday.

Dave