Arduino M0 Pro (48pin package) Bootloader can also be used with 64pin package

Hello there,

I'm planning to use Arduino M0 Pro for one of my application, but no of GPIOs are less on it. So I want to go with 64 pin package.

Now the question is, whether the 48 pin package Arduino M0 Bootloader, will be compatible for 64 Pin package.???
Is there any setting, where I can specify that the micro-controller I'm using is 64 pin package and bootloader will take take of remaining settings and manage the 64 pin package aswell for the ease of usage.??
I need around 16 GPIOs, 4 ADC, 4 PWM.

Looking forward to a quick response. I'm actually gated by this information.
I don't want to use Arduino Due, as it is a overkill for the application what I'm looking for.


The bootloader should be compatible.

There will be a fair amount of other work required to create a 64pin "variant"

16 GPIO+4ADC+4PWM should fit in a 48pin package, although not the M0 Pro since it connects a bunch of the pins to board-level peripherals (mostly to the edbg chip.) Unfortunately, I don't know of any "standardized" pinouts for "bigger than an Uno but smaller than a Mega" :frowning:
Don't forget that there are more than 13 IO pins on an M0-like board - the 6pin SPI connector, the two pins of I2C IO, and D0/D1 "Serial" pins are independent of the other pins (unlike an Uno, where SPI is common with 10/11/12, I2C is common with A4/A5, and D0/D1 are used for the host connection. That means about 19 usable digital IO, plus the 6 analog pins.

If you were to get SparkFun's SAMD21 board, there are an additional 3 pins broken out. And if you got rid of the rx/tx LEDs that's 2 more. And Aref is theoretically re-purposable.

Dear @westfw ,

Thanks for your quick response. Please find the below pin out image, it shows that it has lot of pins which are shared between multiple functionalities. Here, Digital Pins are shared with PWM pins and if I want one extra soft-UART also, I don't have option to do so. That's the reason I wanted to move to the 64 pin package, where I will get more no of digital pins.

And Why I'm asking about the boot loader, is because if I use the same boot loader for 64pin package, it will have information of 48 pin package only and remaining pins will be useless. This scenario will not be helpful.

  1. Is there any specific setting that bootloader have to be adjusted to work on different pin packages of same core.??
  2. Is bootloader is smart enough to handle this by itself and we don't need to worry about it.??

Lokesh J.