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Aref jumper on M4 Airlift Lite
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Aref jumper on M4 Airlift Lite

by dkirkby on Mon Feb 22, 2021 10:14 pm

The airlift pinout page says:
On the Metro M4 Express AirLift, at least for now, AREF is tied to 3.3V due to a silicon v0 bug that does not allow the DACs to work unless AREF is connected to 3.3V. You cut the bottom jumper if you need a different AREF voltage but note that this may change DAC range!

However, I don't see this jumper so did this problem get fixed and I can provide my own AREF < 3.3V? (I do see the jumper on a Metro M4 Express, so I know what to look for).

dkirkby
 
Posts: 3
Joined: Tue Dec 18, 2018 11:02 am

Re: Aref jumper on M4 Airlift Lite

by dkirkby on Mon Feb 22, 2021 10:26 pm

I see the AREF jumper is still on the schematic and I do see one jumper on the top side, right next to the Airlift logo on the silkscreen. However, the schematic shows 2 jumpers, for AREF and USHIELD.

dkirkby
 
Posts: 3
Joined: Tue Dec 18, 2018 11:02 am

Re: Aref jumper on M4 Airlift Lite

by dkirkby on Tue Feb 23, 2021 12:08 pm

Testing with a multimeter, I see a short between 3.3V and AREF so these are still connected. However, the jumper is now on the front side (confirmed with the multimeter) and unlabeled, not the back as stated in the product page.

dkirkby
 
Posts: 3
Joined: Tue Dec 18, 2018 11:02 am

Please be positive and constructive with your questions and comments.