Use Internal Oscillator when Flashing a bare ATSAMD21E18A wi

[craigfoo]

I have a standalone ATSAMD21E18A on a breakout board that I'm trying to flash. I've followed the steps here, https://learn.adafruit.com/how-to-progr ... mel-studio, to burn the bootloader. It looks like it took just fine. Then, it seems like I can flash the standalone chip over the jlink interface but then it just does nothing.

I've successfully done this process with a Trinket M0 and I'm using PlatformIO to do step-through debugging using jlink. I compared the fuses of each and I had a hunch that the standalone chip isn't using the internal oscillator for some reason. Am I wrong? How can I confirm that the internal oscillator is being used?

standalone.png (73.57 KiB) Viewed 190 times

trinket.png (70.99 KiB) Viewed 190 times

[42volts]

Well, the "trinket m0" *is* just a "SAMD21E18A on a breakout board" -- so treat the two exactly the same way!

And make sure that the bootloader you install to it is one that works with the internal oscillator, or it will never jump to your code.

[craigfoo]

I had the same thought, there's not much going on on the Trinket M0 so it should be easy peasy. I burn the same bootloader on both boards, the Trinket M0 executes my app just fine but the bare bones one doesn't. Not sure why the bare one isn't behaving the same even with the same bootloader.

[craigfoo]

I revisited this project and I'm still struggling with this issue. I can get the Trinket M0 to dance but the bare uC just sits there. If I'm burning the bare uC with the Trinket M0 bootloader, I expect to behave just like the Trinket M0...but it's not. Any other thoughts out there?

[craigfoo]

Is there anybody in there? Just nod if you can hear me. Is there anyone home?