Mohammad

I believe I've found the problem. It is a bug in the way the new chip handles sleep mode. It escaped notice in previous testing because the bug doesn't manifest unless sleep modes are also combined with soft reboot. I'm testing a fix now...

Yes, you can leave pin 21 unconnected. You should be able to reproduce the problem with the code in msg #6. The issue might happen either after some minutes, an hour or even several hours. It is not consistent, but it will happen with GD32E230F8...

Hi Paul, Thanks for testing and for your quick response. Yes, you're right; in order for the SnoozeAlarm (RTC wakeup) to function correctly, the Teensy 3.2 needs a 32.768 kHz crystal soldered on. I have this crystal installed on all the boards...

Done! Thanks

Thanks for your reply. I ran a very simple test overnight using the Blink + Hibernate + Software Reboot cycle — and unfortunately, the board got stuck in bootloader mode again by morning. This confirms that the issue is reproducible with minimal...

Just an update: I tested the Teensy 3.2 boards that use the GD32E230F8 (LGA20) bootloader chip by trying: A 100Ω pull-up from Program to 3.3V And even directly shorting Program to 3.3V Unfortunately, the issue persists, and the board still...

Quick correction to my earlier post: I previously said that the Teensy 3.2 boards without bootloader issues were using the Mini54 chip — but that was incorrect. After closer inspection, the boards that are working fine actually use the...

I have been using two different versions of T3.2 for a while. I have recently noticed occasional sticking in bootloader mode when booting up. This only occurs on T3.2 models with the MKL02 bootloader chip. There is no issue with those using the...