The NMEA4Wifi is from March 2020 and has the wide black-PCB Wemos ESP module. It had worked well with v38 as received.
The OTA upgrade to v49 appeared successful, but afterwards it would only boot successfully approx 1 in 3 times:
- appeared to go through the normal boot process: all green LEDs flashing together then in sequence left to right and right to left
- then hung about 2 times in 3, with no wifi and P1-P4 data input LEDs showing a very faint continuous green
- about 1 in 3 times it did not hang, completed boot and ran normally
- when it did hang, repeated reboots would finally succeed in a normal boot
It looked as if something in the v49 firmware might be marginal, leading to hanging sometimes but not always during boot. The timing seems to put the problem during wifi connection, so a possibility is that the high current is triggering the brownout detector. The comparatively old ESP module tested might be vulnerable where another ESP module design is OK.
There was a similar suggestion that a change in OTA code might have caused a brownouts in v34 in www.vela-navega.com/forum/viewtopic.php?f=13&t=164.
Is there any change in v49 or previous post-v38 versions that might have lowered the ESP brownout trigger level or increased power consumption during wifi startup so as to trigger a brownout? Or another explanation?