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geekhack Community => Keyboards => Topic started by: bogomips on Sun, 08 November 2020, 16:53:32

Title: Can I swap ATMEGA32U4-AU for ATMEGA32U4-MUR?
Post by: bogomips on Sun, 08 November 2020, 16:53:32

Hi

I'm still leaning keyboard PCB design. I've completed 1 macropad PCB project with a ATMEGA32U4-AU and it worked great - manufactured by PCBWay.
It already has a bootloader on, and you can load a QMK build when you hit the reset switch. USB just worked.

My next project I want to have manufactured by JLCPCB - however their ATMEGA32U4-AU are permanently out of stock. They do have a pile of ATMEGA32u4-MUR however...

In my design, can I just just swap out the -AU for the -MUR?

Is it just the package which is different?

Will it have the same bootloader? (DFU I believe)

Thanks

Title: Re: Can I swap ATMEGA32U4-AU for ATMEGA32U4-MUR?
Post by: yui on Mon, 09 November 2020, 03:01:22

the part after the "-" is only for package and temperature tolerances the part before does describe the possessor, so as long as it starts by ATMEGA32U4 it will be compatible from a firmware level
from the datasheet you only seem to go from TQFP to QFN and the placement of the pins is the same, so just will have to change the footprint of the new part.
http://ww1.microchip.com/downloads/en/DeviceDoc/Atmel-7766-8-bit-AVR-ATmega16U4-32U4_Summary.pdf
and the R from mouser's comparator is that it comes in reels instead of trays, likely why JLC switched. although they may have the AUR version.

Title: Re: Can I swap ATMEGA32U4-AU for ATMEGA32U4-MUR?
Post by: bogomips on Mon, 09 November 2020, 15:04:24

Awesome, thank you yui :)