DAC outputs

Questions on other types of hardware and getting it talking to the ARM CPU
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YahooArchive
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Joined: Fri Oct 19, 2012 5:11 am

DAC outputs

Post by YahooArchive » Thu Dec 06, 2012 5:15 pm

>Question from help line.

There are a number of ways to get an analog output.

The first is to use HWPWM and then filter that with a simple RC filter. While
this won't be the most accurate and depending on your filter may ripple a bit,
but in many cases its a pretty effective method.

The ARMweb has an integral D/A which is fairly simple to program. Enable the
PINSEL register and load values into DACOUT registers (details in the user
manual).

Next would be to add an external serial D/A. An LTC1448 is a good dual D/A part
and available in DIP packages.

Parallel devices are usable, but requires a lot of IOs.

To get a 4-20mA output, you would need a voltage to current converter. The
XTR110 is a dedicated device for this, or you can use various op amp circuits.



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