NMEA4Wifi firmware v49 upgrade

Discussion and support for the Nmea4Wifi multiplexer - a 4-input Nmea 0183 wifi multiplexer.
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NMEA4Wifi firmware v49 upgrade

Post by zambak » Tue Jun 28, 2022 1:32 pm

I had a problem after upgrading a NMEA4Wifi to v49.
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
After reverting to v38 it ran normally without hanging, just as before the upgrade, so it is unlikely to be due to the external environment or power.
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?

Luis Sa
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Re: NMEA4Wifi firmware v49 upgrade

Post by Luis Sa » Tue Jun 28, 2022 5:28 pm


Thank you for your detailed report. Unfortunately I am in Turkey and I have limited (or none) capacity to repeat your tests. There have been some problems with the 12 to 5V regulator. Specifically if this regulator has the red colour. More than a year ago I am using a custom voltage regulator designed by me. Then the ESP32 module has a 5V to 3V3 voltage regulator. The "old black" ESP32 module had a good regulator. Later we had used a module known as "MH-ET" that had a tiny 5V to 3V3 regulator. Present multiplexer is supplied with our own designed module.

Your description suggests a problem with the power supply during the starting of the WiFi network. The WiFi programming sequence has changed and I will only have the capacity to research this when I return home in mid September.

I would be grateful if you could send to my email a photo of the multiplexer so that I can identify your unit.

Best Regards, Luis

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Joined: Mon Jun 20, 2022 8:05 pm

Re: NMEA4Wifi firmware v49 upgrade

Post by zambak » Tue Jun 28, 2022 8:20 pm

Thank your for your quick response.
There is no urgency about this - v38 works with no problems. I was curious as to the cause of the hang, and to make sure that there will be a path if I do need to upgrade from v38. So September or later is no problem.
I have sent a photo to your email - the 12V-5V regulator board is red, so may be the cause of the problem.
Hope Turkey is good, and to hear from you later in the year.


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