Has anyone tried using the simple UART bootloader put out by Microchip on the mega4809 curiosity nano? Here: https://www.microchip.com/wwwApp...
It's basically just transmitting the hex file byte by byte and verifying with an echo after each transmission. I'm using the virtual COM port on the on-board nedbg.
On this board the bootloading is pathetically slow - I'm talking over 60-70 seconds for a 7000 byte transfer (I've modified it to transfer only the required number of pages instead of padding and filling the whole flash).
Using the same bootloader on the attiny817 xplained mini board is very fast, the transfer would probably take about a tenth of the time or lesser. Maybe the difference is the edbg chip - 4809 cnano has a SAMD21 while the 817xm has a mega32U4. I've had this issue before (https://www.avrfreaks.net/forum/...) and found that the USB-serial chip makes a world of difference, but this performance is the worst I've seen by far.
Would be glad to know if anyone has had a different experience, or anything I can do to make this better. I'm using a Mac, in case that makes a difference.
Thanks, and stay safe.