Analog ground and AREF on ATMega6450 when not using ADC

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I'm working on an ATMega6450 design that won't be using the ADC.  The data sheet says to connect AVCC to VCC in this case, but says nothing about AGND or AREF.  Should AGND be connected to GND?  AREF to VCC?  Thanks.

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Agnd must be connected to gnd. Aref can be not connected but i'd suggest the internal reference be connected via software.

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Thanks!

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Can't remember but AVR040 and AVR042 are always worth reading when considering laying down AVR circuits and I think one of them has details about what to do with unused peripherals.

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Thanks, it's 042 that talks about this.

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lautman wrote:
Thanks, it's 042 that talks about this.

That should solve many things, as

group of hyper-intelligent pan-dimensional beings demand to learn the Answer to the Ultimate Question of Life, The Universe, and Everything from the supercomputer, Deep Thought, specially built for this purpose. It takes Deep Thought 7½ million years to compute and check the answer, which turns out to be 42. Deep Thought points out that the answer seems meaningless because the beings who instructed it never actually knew what the Question was.[1]

https://en.wikipedia.org/wiki/Ph...

 

;)

 

I was going to give a RTFM answer, but indeed in that family datasheet there is no mention of AGND in Pin Descriptions.  Some other datasheets:

 

 

 

You can put lipstick on a pig, but it is still a pig.

I've never met a pig I didn't like, as long as you have some salt and pepper.

Last Edited: Tue. Oct 4, 2016 - 01:21 PM
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Oh well spotted that man! Never made the 42="answer to life the universe and everything" link before now :-O

 

Wonder if Atmel saved 042 for that very reason?

 

(in a similar vein (well kind of!) the original IBM PC BIOS used to show error code "1701" to mean "hard disk error" because the number was kind of famous in "USS NC1701 Enterprise" :-)