Firmware upgrade for NOUS A8T fails

[wjohn007]

I tried to update my NOUS A8T Smart Plug.
Here's what happened:

The original firmware was Tasmota 14.3.

14.6 OK http://ota.tasmota.com/tasmota32/release-14.6.0/tasmota32.bin

15.0.1 OK http://ota.tasmota.com/tasmota32/release-15.0.1/tasmota32.bin

15.1 Error http://ota.tasmota.com/tasmota32/release-15.1.0/tasmota32.bin, remains in safe mode.

15.2 Error http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin, remains in safe mode.

How can I fix this?

[arendst]

What is your safe mode Tasmota Version?

What happens when you execute restart 3

BTW my update from 15.0.1 to 15.1.0 went OK. update from 15.1.0 to 15.2.0 also went OK.

[wjohn007]

Hello Theo, thank you very much for your support.
I'm using this bootloader:

tasmota-nous-002 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)

After an unsuccessful update attempt, the following log output is displayed.

00:00:00.002 HDW: ESP32-U4WDH-D v3.1 
00:00:00.005 CFG: Loaded from NVS, Count 183
00:00:00.007 CFG: CR 431/699, Busy 0
00:00:00.010 Project tasmota - tasmota-nous-002 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)
00:00:00.010 WARNING This version does not support persistent settings
00:00:00.272 WIF: Attempting connection...
00:00:01.345 WIF: Connecting to AP1 FBDG Channel 1 BSSId 0C:72:74:3E:71:D9 in mode  as tasmota-nous-002-1680...
00:00:02.643 WIF: Attempting connection...
00:00:03.890 WIF: Attempting connection...
00:00:04.368 WIF: IPv4 192.168.178.115, mask 255.255.255.0, gateway 192.168.178.1
00:00:04.898 WIF: Connected
00:00:05.087 RTC: UTC 2025-12-31T15:14:09Z, DST 2025-03-30T02:00:00, STD 2025-10-26T03:00:00
16:14:09.000 RTC: Synced by NTP
16:14:09.054 HTP: Web server active on tasmota-nous-002-1680 with IP address 192.168.178.115
16:14:09.376 WIF: IPv6 Local fe80::2ebc:bbff:fed7:4690%st1
16:14:10.149 MQT: Attempting connection...
16:14:10.206 MQT: Connected
16:14:10.212 MQT: tele/tasmota_nous_002/LWT = Online (retained)
16:14:10.214 MQT: cmnd/tasmota_nous_002/POWER = 
16:14:10.215 MQT: Subscribe to cmnd/tasmota_nous_002/#
16:14:10.216 MQT: Subscribe to cmnd/tasmotas/#
16:14:10.217 MQT: Subscribe to cmnd/DVES_D74690_fb/#
16:14:10.219 MQT: tele/tasmota_nous_002/INFO1 = {"Info1":{"Module":"Nous A8T","Version":"15.0.1(release-safeboot)single-core","FallbackTopic":"cmnd/DVES_D74690_fb/","GroupTopic":"cmnd/tasmotas/"}}
16:14:10.231 MQT: tele/tasmota_nous_002/INFO2 = ...
16:14:10.253 MQT: tele/tasmota_nous_002/INFO3 = {"Info3":{"RestartReason":"Software reset CPU","BootCount":79}}
16:14:10.271 MQT: stat/tasmota_nous_002/RESULT = {"POWER":"OFF"}
16:14:10.273 MQT: stat/tasmota_nous_002/POWER = OFF
16:14:11.466 WIF: IPv6 Global 2003:ee:712:e900:2ebc:bbff:fed7:4690
16:14:11.467 WIF: IPv6 Global fd6d:e2b:6d00:0:2ebc:bbff:fed7:4690
16:14:12.993 APP: Boot Count 79

[arendst]

OK. I've installed safeboot version 15.0.1 too:

00:00:00.002 HDW: ESP32-U4WDH-D v3.1 
00:00:00.006 CFG: Loaded from NVS, Count 66
00:00:00.009 SRC: Restart
00:00:00.010 Project tasmota - NousA8T2 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)
00:00:00.010 WARNING This version does not support persistent settings
00:00:00.261 WIF: Attempting connection...
00:00:01.003 WIF: Connecting to AP1 indebuurt_IoT Channel 1 BSSId 74:83:C2:2A:F1:AC in mode HT40 as nousa8t2...
00:00:01.084 WIF: IPv4 192.168.2.191, mask 255.255.255.0, gateway 192.168.2.254
00:00:02.845 WIF: Connected
00:00:03.452 WIF: IPv6 Local fe80::feb4:67ff:fe34:b53c%st1
00:00:04.001 WIF: DNS failed for 2.pool.ntp.org after 1007 ms
00:00:04.006 HTP: Web server active on nousa8t2 with IP address 192.168.2.191
00:00:04.314 RTC: UTC 2026-01-01T13:26:50Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
14:26:50.000 RTC: Synced by NTP
14:26:51.025 MQT: Attempting connection...
14:26:51.052 MQT: Connected
14:26:51.058 MQT: tele/nousa8t2/LWT = Online (retained)
14:26:51.059 MQT: cmnd/nousa8t2/POWER = 
14:26:51.060 MQT: Subscribe to cmnd/nousa8t2/#
14:26:51.061 MQT: Subscribe to cmnd/tasmotas/#
14:26:51.062 MQT: Subscribe to cmnd/DVES_34B53C_fb/#
14:26:51.064 MQT: tele/nousa8t2/INFO1 = {"Info1":{"Module":"NOUS A8T","Version":"15.0.1(release-safeboot)single-core","FallbackTopic":"cmnd/DVES_34B53C_fb/","GroupTopic":"cmnd/tasmotas/"}}
14:26:51.066 MQT: tele/nousa8t2/INFO2 = {"Info2":{"WebServerMode":"Admin","Hostname":"nousa8t2","IPAddress":"192.168.2.191","IP6Global":"","IP6Local":"fe80::feb4:67ff:fe34:b53c%st1"}}
14:26:51.067 MQT: tele/nousa8t2/INFO3 = {"Info3":{"RestartReason":"Software reset CPU","BootCount":25}}
14:26:51.068 MQT: stat/nousa8t2/RESULT = {"POWER":"OFF"}
14:26:51.069 MQT: stat/nousa8t2/POWER = OFF
14:26:53.455 WIF: IPv6 Global fd84:7996:2cbf:1349:feb4:67ff:fe34:b53c
14:26:54.989 APP: Boot Count 25
14:26:55.001 MQT: tele/nousa8t2/STATE = {"Time":"2026-01-01T14:26:54","Uptime":"0T00:00:09","UptimeSec":9,"Heap":216,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":19,"MqttCount":1,"POWER":"OFF","Wifi":{"AP":1,"SSId":"indebuurt_IoT","BSSId":"74:83:C2:2A:F1:AC","Channel":1,"Mode":"HT40","RSSI":32,"Signal":-84,"LinkCount":1,"Downtime":"0T00:00:03"}}

I then executed command otaurl http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin

14:27:52.674 CMD: otaurl http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin
14:27:52.675 SRC: WebConsole from 192.168.2.1
14:27:52.675 CMD: Grp 0, Cmd 'OTAURL', Idx 1, Len 61, Pld -99, Data 'http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin'
14:27:52.676 CFG: CR 414/699, Busy 0
14:27:52.680 MQT: stat/nousa8t2/RESULT = {"OtaUrl":"http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin"}

Followed by command upload 1

14:28:33.509 CMD: upload 1
14:28:33.510 SRC: WebConsole from 192.168.2.1
14:28:33.511 CMD: Grp 0, Cmd 'UPLOAD', Idx 1, Len 1, Pld 1, Data '1'
14:28:33.516 MQT: stat/nousa8t2/RESULT = {"Upload":"Version 15.0.1 from http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin"}
14:28:35.513 UPL: http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin 15.0.1(release-safeboot)
14:28:37.946 OTA: Connection timeout after 1005 ms
14:28:40.772 OTA: Connected in 210 ms, stack low mark 5076
14:29:15.432 MQT: stat/nousa8t2/UPGRADE = {"Upgrade":"Successful. Restarting"}

The device will restart and should display:

00:00:00.003 HDW: ESP32-U4WDH-D v3.1 
00:00:00.051 UFS: FlashFS mounted with 300 kB free
00:00:00.063 CFG: Loaded from File, Count 66
00:00:00.219 CFG: Saved, Count 67, Bytes 4096
00:00:00.222 QPC: Count 1
00:00:00.228 TYA: Active=0
00:00:00.232 ROT: Mode 1
00:00:00.281 CFG: No '*.autoconf' file found
00:00:00.289 BRY: Berry initialized, RAM used 3766 bytes
00:00:00.299 BRY: No 'preinit.be'
00:00:00.318 CFG: Energy loaded from file
00:00:00.318 NRG: Init driver 1
00:00:00.320 SRC: Restart
00:00:00.326 Project tasmota - NousA8T2 Version 15.2.0(release-tasmota32)-3.3.4(2025-12-12T10:58:29)
00:00:00.326 DOM: Support 1 Device(s), 1 Button(s), 0 Switch(es) and 11 Sensors
00:00:00.371 CFG: Domoticz loaded from file
00:00:00.420 BRY: No 'autoexec.be'
00:00:00.735 CFG: Domoticz saved to file
00:00:00.935 WIF: Attempting connection...
00:00:01.382 WIF: Connecting to AP1 indebuurt_IoT Channel 1 BSSId 74:83:C2:2A:F1:AC in mode HT40 as nousa8t2...
00:00:02.104 WIF: IPv4 192.168.2.191, mask 255.255.255.0, gateway 192.168.2.254
00:00:03.914 WIF: IPv6 Local fe80::feb4:67ff:fe34:b53c%st1
00:00:04.089 WIF: Connected
00:00:04.301 HTP: Web server active on nousa8t2 with IP address 192.168.2.191
00:00:04.953 RTC: UTC 2026-01-01T13:29:26Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
14:29:26.000 RTC: Synced by NTP
14:29:26.315 MQT: Attempting connection...
14:29:26.340 MQT: Connected
14:29:26.344 MQT: tele/nousa8t2/LWT = Online (retained)
14:29:26.346 MQT: cmnd/nousa8t2/POWER = 
14:29:26.346 MQT: Subscribe to cmnd/nousa8t2/#
14:29:26.348 MQT: Subscribe to cmnd/tasmotas/#
14:29:26.349 MQT: Subscribe to cmnd/DVES_34B53C_fb/#
14:29:26.353 MQT: tele/nousa8t2/INFO1 = {"Info1":{"Module":"NOUS A8T","Version":"15.2.0(release-tasmota32)","FallbackTopic":"cmnd/DVES_34B53C_fb/","GroupTopic":"cmnd/tasmotas/"}}
14:29:26.357 MQT: tele/nousa8t2/INFO2 = {"Info2":{"WebServerMode":"Admin","Hostname":"nousa8t2","IPAddress":"192.168.2.191","IP6Global":"","IP6Local":"fe80::feb4:67ff:fe34:b53c%st1"}}
14:29:26.360 MQT: tele/nousa8t2/INFO3 = {"Info3":{"RestartReason":"Software reset CPU","BootCount":25}}
14:29:26.363 MQT: stat/nousa8t2/RESULT = {"POWER":"OFF"}
14:29:26.365 MQT: stat/nousa8t2/POWER = OFF
14:29:28.784 QPC: Reset
14:29:28.914 WIF: IPv6 Global fd84:7996:2cbf:1349:feb4:67ff:fe34:b53c
14:29:30.764 APP: Boot Count 25
14:29:30.774 MQT: tele/nousa8t2/STATE = {"Time":"2026-01-01T14:29:30","Uptime":"0T00:00:09","UptimeSec":9,"Heap":119,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":19,"MqttCount":1,"Berry":{"HeapUsed":4,"Objects":51},"POWER":"OFF","Wifi":{"AP":1,"SSId":"indebuurt_IoT","BSSId":"74:83:C2:2A:F1:AC","Channel":1,"Mode":"HT40","RSSI":32,"Signal":-84,"LinkCount":1,"Downtime":"0T00:00:04"},"Hostname":"nousa8t2","IPAddress":"192.168.2.191"}
14:29:30.785 MQT: tele/nousa8t2/SENSOR = {"Time":"2026-01-01T14:29:30","ENERGY":{"TotalStartTime":"2024-09-14T15:21:00","Total":0.001,"Yesterday":0.000,"Today":0.000,"Period":0.00,"Power":0.00,"ApparentPower":0.00,"ReactivePower":0.00,"Factor":0.00,"Voltage":221.2,"Current":0.000}}
14:29:30.946 CFG: Saved, Count 68, Bytes 4096

Notice that the result of command otaurl will probably show NOT http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin. This is because you changed it in safeboot which is not saved. For future use change it here too using command otaurl http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin.

If your output looks different pls let me know.

EDIT1: For future use: If you start the console in production mode and execute upload 1 the device will reboot in safeboot mode and display information until the webserver is halted by the ota code. This way it looks as if nothing happens on the console but the system is still busy downloading the requested otaurl binary. As the webserver needs to be stopped during this process you won't see anything. Wait for about a minute for the webserver to restart and display the finish or fail message on the console. IN THE MEANTIME DO NOTHING until anything is being shown again OR two minutes have elapsed (indicating it failed)

[wjohn007]

Hi Theo,

here's the log output for each command.

Unfortunately, no change.

otaurl http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin

10:45:35.279 CMD: otaurl http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin
10:45:35.280 SRC: WebConsole from 192.168.178.216
10:45:35.281 CMD: Grp 0, Cmd 'OTAURL', Idx 1, Len 61, Pld -99, Data 'http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin'
10:45:35.281 CFG: CR 438/699, Busy 0
10:45:35.287 MQT: stat/tasmota_nous_002/RESULT = {"OtaUrl":"http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin"}

upload 1

10:55:15.824 CMD: upload 1
10:55:15.825 SRC: WebConsole from 192.168.178.216
10:55:15.826 CMD: Grp 0, Cmd 'UPLOAD', Idx 1, Len 1, Pld 1, Data '1'
10:55:15.832 MQT: stat/tasmota_nous_002/RESULT = {"Upload":"Version 15.0.1 from http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin"}
10:55:18.641 UPL: http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin 15.0.1(release-safeboot)
10:55:20.144 OTA: Connected in 66 ms, stack low mark 5044
10:55:58.539 MQT: stat/tasmota_nous_002/UPGRADE = {"Upgrade":"Successful. Restarting"}

Here we are back in safe boot mode.

00:00:00.002 HDW: ESP32-U4WDH-D v3.1 
00:00:00.006 CFG: Loaded from NVS, Count 208
00:00:00.007 CFG: CR 438/699, Busy 0
00:00:00.010 Project tasmota - tasmota-nous-002 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)
00:00:00.010 WARNING This version does not support persistent settings
00:00:00.272 WIF: Attempting connection...
00:00:01.003 WIF: Connecting to AP1 FBDG Channel 1 BSSId 0C:72:74:3E:71:D9 in mode HE20 as tasmota-nous-002-1680...
00:00:01.080 WIF: IPv4 192.168.178.115, mask 255.255.255.0, gateway 192.168.178.1
00:00:02.872 WIF: Connected
00:00:03.085 RTC: UTC 2026-01-03T09:56:16Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
10:56:16.000 RTC: Synced by NTP
10:56:16.054 HTP: Web server active on tasmota-nous-002-1680 with IP address 192.168.178.115
10:56:16.380 WIF: IPv6 Local fe80::2ebc:bbff:fed7:4690%st1
10:56:17.144 MQT: Attempting connection...
10:56:17.191 MQT: Connected

[arendst]

What happens when executing command restart 3

If back in safe boot I have no solution at the moment as safe boot is very limited on available commands to debug/trick the code.

You might want to try to go back to release-15.0.1 and see if that is able to switch out of safe boot.

[wjohn007]

You might want to try to go back to release-15.0.1 and see if that is able to switch out of safe boot.

That's possible at any time

What happens when executing command restart 3

Under which initial scenario

[arendst]

Under which initial scenario

The current scenarion.

That's possible at any time

You're saying doing otaurl http://ota.tasmota.com/tasmota32/release-15.0.1/tasmota32.bin and upload 1 brings you out of safe boot mode?

[wjohn007]

You're saying doing otaurl http://ota.tasmota.com/tasmota32/release-15.0.1/tasmota32.bin and upload 1 brings you out of safe boot mode?

Yes, that's right.

00:00:00.003 HDW: ESP32-U4WDH-D v3.1 
00:00:00.056 UFS: FlashFS mounted with 288 kB free
00:00:00.073 CFG: Loaded from File, Count 217
00:00:00.083 QPC: Count 1
00:00:00.085 CFG: CR 438/699, Busy 0
00:00:00.091 TYA: Active=0
00:00:00.098 ROT: Mode 1
00:00:00.153 CFG: No '*.autoconf' file found
00:00:00.160 BRY: Berry initialized, RAM used 3493 bytes
00:00:00.170 BRY: No 'preinit.be'
00:00:00.202 CFG: Energy loaded from file
00:00:00.202 NRG: Init driver 1
00:00:00.207 Project tasmota - tasmota-nous-002 Version 15.0.1(release-tasmota32)-3_1_3(2025-06-14T10:34:57)
00:00:00.271 BRY: No 'autoexec.be'
00:00:00.523 WIF: Attempting connection...
00:00:01.093 WIF: Connecting to AP1 FBDG Channel 1 BSSId 0C:72:74:3E:71:D9 in mode HE20 as tasmota-nous-002-1680...
00:00:02.572 WIF: IPv4 192.168.178.115, mask 255.255.255.0, gateway 192.168.178.1
00:00:03.640 WIF: IPv6 Local fe80::2ebc:bbff:fed7:4690%st1
00:00:03.748 WIF: Connected
00:00:03.958 RTC: UTC 2026-01-03T20:51:21Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
21:51:21.001 RTC: Synced by NTP
21:51:21.027 HTP: Web server active on tasmota-nous-002-1680 with IP address 192.168.178.115
21:51:21.419 HTP: Console
21:51:21.980 MQT: Attempting connection...
21:51:22.029 MQT: Connected

[arendst]

Oh my. I have no clue why this is happening. What I do see is that with every restart you have a line CFG: CR 438/699, Busy 0 indicating something is changing the config where it shouldn't. I also see you're connecting wifi with 11ax (HE20). But I don't see why that could cause you issue too.

Pls provide the output of command status 0 and a screen picture of page Information.

[wjohn007]

For your information, I have two Nous A8T units in use. Both have the same problem.

Status 0

17:04:10.912 MQT: stat/tasmota_nous_002/STATUS = {"Status":{"Module":0,"DeviceName":"tasmota-nous-002","FriendlyName":["tasmota-nous-002"],"Topic":"tasmota_nous_002","ButtonTopic":"0","Power":"0","PowerLock":"0","PowerOnState":0,"LedState":1,"LedMask":"FFFF","SaveData":3600,"SaveState":0,"SwitchTopic":"0","SwitchMode":[0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0],"ButtonRetain":0,"SwitchRetain":0,"SensorRetain":0,"PowerRetain":0,"InfoRetain":0,"StateRetain":0,"StatusRetain":0}}
17:04:10.918 MQT: stat/tasmota_nous_002/STATUS1 = {"StatusPRM":{"Baudrate":115200,"SerialConfig":"8N1","GroupTopic":"tasmotas","OtaUrl":"http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32.bin","RestartReason":"Software reset CPU","Uptime":"1T19:12:53","StartupUTC":"2026-01-03T20:51:17","Sleep":50,"CfgHolder":4617,"BootCount":89,"BCResetTime":"2025-09-27T18:05:45","SaveCount":218}}
17:04:10.922 MQT: stat/tasmota_nous_002/STATUS2 = {"StatusFWR":{"Version":"15.0.1(release-tasmota32)","BuildDateTime":"2025-06-14T10:34:57","Core":"3_1_3","SDK":"5.3.3.250501","CpuFrequency":160,"Hardware":"ESP32-U4WDH-D v3.1","CR":"438/699"}}
17:04:10.929 MQT: stat/tasmota_nous_002/STATUS3 = {"StatusLOG":{"SerialLog":2,"WebLog":3,"MqttLog":0,"FileLog":0,"SysLog":0,"LogHost":"192.168.178.102","LogPort":514,"SSId":["FBDG",""],"TelePeriod":30,"Resolution":"558180C0","SetOption":["00000008","2805C80001000600003C5A0A192800000000","00000080","00006000","00004000","00000000"]}}
17:04:10.944 MQT: stat/tasmota_nous_002/STATUS4 = {"StatusMEM":{"ProgramSize":2045,"Free":834,"Heap":151,"StackLowMark":3,"PsrMax":0,"PsrFree":0,"ProgramFlashSize":4096,"FlashSize":4096,"FlashChipId":"164020","FlashFrequency":40,"FlashMode":"DIO","Features":["0809","9F9AD7DF","0015A001","B7F7BFCF","05DA9BC4","E0360DC7","480840D2","20200000","D4BC482D","810A80F1","00000814"],"Drivers":"1,2,3,!4,!5,7,!8,9,10,11,12,!14,!16,!17,!20,!21,!24,26,!27,29,!34,!35,38,50,52,!59,!60,62,!63,!66,!67,!68,!73,!75,82,!86,!87,!88,!91,!121","Sensors":"1,2,3,5,6,7,8,9,10,11,12,13,14,15,17,18,19,20,21,22,26,31,34,37,39,40,42,43,45,51,52,55,56,58,59,64,66,67,74,85,92,95,98,103,105,109,127","I2CDriver":"7,8,9,10,11,12,13,14,15,17,18,20,24,29,31,36,41,42,44,46,48,58,62,65,69,76,77,82,89"}}
17:04:10.953 MQT: stat/tasmota_nous_002/STATUS5 = {"StatusNET":{"Hostname":"tasmota-nous-002-1680","IPAddress":"192.168.178.115","Gateway":"192.168.178.1","Subnetmask":"255.255.255.0","DNSServer1":"192.168.178.1","DNSServer2":"fd6d:e2b:6d00:0:52e6:36ff:fe65:baed","Mac":"2C:BC:BB:D7:46:90","IP6Global":"2003:ee:712:e900:2ebc:bbff:fed7:4690","IP6Local":"fe80::2ebc:bbff:fed7:4690%st1","Ethernet":{"Hostname":"","IPAddress":"0.0.0.0","Gateway":"0.0.0.0","Subnetmask":"0.0.0.0","DNSServer1":"192.168.178.1","DNSServer2":"fd6d:e2b:6d00:0:52e6:36ff:fe65:baed","Mac":"00:00:00:00:00:00","IP6Global":"","IP6Local":""},"Webserver":2,"HTTP_API":1,"WifiConfig":4,"WifiPower":16.0}}
17:04:10.961 MQT: stat/tasmota_nous_002/STATUS6 = {"StatusMQT":{"MqttHost":"cubietruck","MqttPort":1883,"MqttClientMask":"DVES_%06X","MqttClient":"DVES_D74690","MqttUser":"DVES_USER","MqttCount":1,"MqttTLS":0,"MAX_PACKET_SIZE":1200,"KEEPALIVE":30,"SOCKET_TIMEOUT":4}}
17:04:10.966 MQT: stat/tasmota_nous_002/STATUS7 = {"StatusTIM":{"UTC":"2026-01-05T16:04:10Z","Local":"2026-01-05T17:04:10","StartDST":"2026-03-29T02:00:00","EndDST":"2026-10-25T03:00:00","Timezone":99,"Sunrise":"08:43","Sunset":"17:07"}}
17:04:10.971 MQT: stat/tasmota_nous_002/STATUS9 = {"StatusPTH":{"PowerDelta":0,"PowerLow":0,"PowerHigh":0,"VoltageLow":0,"VoltageHigh":0,"CurrentLow":0,"CurrentHigh":0,"MaxPower":0,"MaxPowerHold":10,"MaxPowerWindow":30,"MaxEnergy":0,"MaxEnergyStart":0}}
17:04:10.988 MQT: stat/tasmota_nous_002/STATUS10 = {"StatusSNS":{"Time":"2026-01-05T17:04:10","ENERGY":{"TotalStartTime":"2025-12-21T18:20:54","Total":30.138,"Yesterday":0.000,"Today":0.000,"Power":0,"ApparentPower":0,"ReactivePower":0,"Factor":0.00,"Voltage":0,"Current":0.000}}}
17:04:10.998 MQT: stat/tasmota_nous_002/STATUS11 = {"StatusSTS":{"Time":"2026-01-05T17:04:10","Uptime":"1T19:12:53","UptimeSec":155573,"Heap":148,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":20,"MqttCount":1,"Berry":{"HeapUsed":3,"Objects":44},"POWER":"OFF","PWM":{"PWM1":0},"Wifi":{"AP":1,"SSId":"FBDG","BSSId":"0C:72:74:3E:71:D9","Channel":1,"Mode":"HE20","RSSI":84,"Signal":-58,"LinkCount":1,"Downtime":"0T00:00:03"}}}

[arendst]

I still cannot find why your devices fail to update to v15.1.0

I made some changes to latest dev branch which will make sure it will not enable HT40 (In your case wrongly displayed as HE20) but use HT20 only.

Pls perform:
weblog 4
otaurl http://ota.tasmota.com/tasmota32/tasmota32.bin
upload

And try to catch and provide as much logging as you can.

[sfromis]

Small detail, the last command needs to be upload 1 to actually do something ;-)

[wjohn007]

have done the following

weblog 4
otaurl http://ota.tasmota.com/tasmota32/tasmota32.bin
upload 1

with this result.

00:00:00.002 HDW: ESP32-U4WDH-D v3.1 
00:00:00.005 CFG: Loaded from NVS, Count 220
00:00:00.007 CFG: CR 423/699, Busy 0
00:00:00.010 Project tasmota - tasmota-nous-002 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)
00:00:00.010 WARNING This version does not support persistent settings
00:00:00.271 WIF: Checking connection...
00:00:00.272 WIF: Attempting connection...
00:00:01.002 WIF: Connecting to AP1 FBDG Channel 1 BSSId 0C:72:74:3E:71:D9 in mode HE20 as tasmota-nous-002-1680...
00:00:01.074 WIF: IPv4 192.168.178.115, mask 255.255.255.0, gateway 192.168.178.1
00:00:02.863 WIF: Checking connection...
00:00:02.863 WIF: Connected
00:00:03.014 NTP: Sync time...
00:00:03.035 WIF: DNS resolved '2.pool.ntp.org' (31.209.85.242) in 20 ms
00:00:03.085 RTC: UTC 2026-01-08T07:10:00Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
08:10:00.000 RTC: Synced by NTP
08:10:00.055 HTP: Web server active on tasmota-nous-002-1680 with IP address 192.168.178.115
08:10:00.380 WIF: IPv6 Local fe80::2ebc:bbff:fed7:4690%st1
08:10:01.144 MQT: Attempting connection...
08:10:01.174 WIF: DNS resolved 'cubietruck' (192.168.178.116) in 29 ms
08:10:01.227 MQT: Connected
08:10:01.233 MQT: tele/tasmota_nous_002/LWT = Online (retained)
08:10:01.235 MQT: cmnd/tasmota_nous_002/POWER = 
08:10:01.236 MQT: Subscribe to cmnd/tasmota_nous_002/#
08:10:01.237 MQT: Subscribe to cmnd/tasmotas/#
08:10:01.237 MQT: Subscribe to cmnd/DVES_D74690_fb/#
08:10:01.240 MQT: tele/tasmota_nous_002/INFO1 = {"Info1":{"Module":"Nous A8T","Version":"15.0.1(release-safeboot)single-core","FallbackTopic":"cmnd/DVES_D74690_fb/","GroupTopic":"cmnd/tasmotas/"}}
08:10:01.252 MQT: tele/tasmota_nous_002/INFO2 = {"Info2":{"WebServerMode":"Admin","Hostname":"tasmota-nous-002-1680","IPAddress":"192.168.178.115","IP6Global":"","IP6Local":"fe80::2ebc:bbff:fed7:4690%st1"}}
08:10:01.275 MQT: tele/tasmota_nous_002/INFO3 = {"Info3":{"RestartReason":"Software reset CPU","BootCount":90}}
08:10:01.294 MQT: stat/tasmota_nous_002/RESULT = {"POWER":"OFF"}
08:10:01.300 MQT: stat/tasmota_nous_002/POWER = OFF
08:10:04.466 WIF: IPv6 Global 2003:ee:712:e900:2ebc:bbff:fed7:4690
08:10:04.468 WIF: IPv6 Global fd6d:e2b:6d00:0:2ebc:bbff:fed7:4690
08:10:06.023 APP: Boot Count 90
08:10:06.036 MQT: tele/tasmota_nous_002/STATE = {"Time":"2026-01-08T08:10:06","Uptime":"0T00:00:10","UptimeSec":10,"Heap":217,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":19,"MqttCount":1,"POWER":"OFF","PWM":{"PWM1":0},"Wifi":{"AP":1,"SSId":"FBDG","BSSId":"0C:72:74:3E:71:D9","Channel":1,"Mode":"HE20","RSSI":84,"Signal":-58,"LinkCount":1,"Downtime":"0T00:00:03"}}
08:10:20.152 WIF: Checking connection...

[arendst]

How frustrating.

I'm out of ideas for now.

[arendst]

New plan! Recent versions of Tasmota allow logging to the filesystem. This way I must be able to see what happens if your upload went OK, the new version is starting (and logging to the filesystem) and apparently reverts back to the safeboot partition. Once back in the safeboot partition you cannot access the filesystem so you'll need to re-install v15.0.1 to access the log file in the filesystem.

So the following steps need to be performed when starting from your v15.0.1 safeboot partition:

otaurl http://ota.tasmota.com/tasmota32/release-15.0.1/tasmota32.bin
upload 1

Wait for the console to present the v15.0.1 Tasmota version. Then:

filelog 4
weblog 4
otaurl http://ota.tasmota.com/tasmota32/tasmota32.bin
upload 1

This fails and ends in the safeboot partition but should have stored some logging in the filesystem. Now reinstall v15.0.1 to access the filesystem:

otaurl http://ota.tasmota.com/tasmota32/release-15.0.1/tasmota32.bin
upload 1

Wait for the console to present the v15.0.1 Tasmota version. Then:

• In the GUI go to "Tools", "Manage File system".
• Click on the filename "log01" (which should still be there) and download the file.
• Upload the file here for analysing.

When this has been done you might want to try to use the single core version of Tasmota (as is used by safeboot). In that case, from the safeboot partition do:

otaurl http://ota.tasmota.com/tasmota32/release-15.2.0/tasmota32solo1.bin
upload 1

[wjohn007]

log01.zip
It appears that no file log is created during the safeboot phase.
I miss the content I copied from the console during the safe boot phase.

00:00:00.003 HDW: ESP32-U4WDH-D v3.1 
00:00:00.006 CFG: Loaded from NVS, Count 229
00:00:00.007 CFG: CR 423/699, Busy 0
00:00:00.011 Project tasmota - tasmota-nous-002 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)
00:00:00.011 WARNING This version does not support persistent settings
00:00:00.271 WIF: Checking connection...
00:00:00.272 WIF: Attempting connection...
00:00:01.003 WIF: Connecting to AP1 FBDG Channel 1 BSSId 0C:72:74:3E:71:D9 in mode HE20 as tasmota-nous-002-1680...
00:00:01.068 WIF: IPv4 192.168.178.115, mask 255.255.255.0, gateway 192.168.178.1
00:00:02.872 WIF: Checking connection...
00:00:02.872 WIF: Connected
00:00:03.022 NTP: Sync time...
00:00:03.051 WIF: DNS resolved '2.pool.ntp.org' (212.132.97.26) in 28 ms
00:00:03.087 RTC: UTC 2026-01-08T14:53:19Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
15:53:19.000 RTC: Synced by NTP
15:53:19.054 HTP: Web server active on tasmota-nous-002-1680 with IP address 192.168.178.115
15:53:19.377 WIF: IPv6 Local fe80::2ebc:bbff:fed7:4690%st1
15:53:20.149 MQT: Attempting connection...
15:53:20.162 WIF: DNS resolved 'cubietruck' (192.168.178.116) in 11 ms
15:53:20.214 MQT: Connected
15:53:20.220 MQT: tele/tasmota_nous_002/LWT = Online (retained)
15:53:20.222 MQT: cmnd/tasmota_nous_002/POWER = 
15:53:20.223 MQT: Subscribe to cmnd/tasmota_nous_002/#
15:53:20.224 MQT: Subscribe to cmnd/tasmotas/#
15:53:20.225 MQT: Subscribe to cmnd/DVES_D74690_fb/#
15:53:20.227 MQT: tele/tasmota_nous_002/INFO1 = {"Info1":{"Module":"Nous A8T","Version":"15.0.1(release-safeboot)single-core","FallbackTopic":"cmnd/DVES_D74690_fb/","GroupTopic":"cmnd/tasmotas/"}}
15:53:20.239 MQT: tele/tasmota_nous_002/INFO2 = {"Info2":{"WebServerMode":"Admin","Hostname":"tasmota-nous-002-1680","IPAddress":"192.168.178.115","IP6Global":"","IP6Local":"fe80::2ebc:bbff:fed7:4690%st1"}}
15:53:20.262 MQT: tele/tasmota_nous_002/INFO3 = {"Info3":{"RestartReason":"Software reset CPU","BootCount":93}}
15:53:20.281 MQT: stat/tasmota_nous_002/RESULT = {"POWER":"OFF"}
15:53:20.283 MQT: stat/tasmota_nous_002/POWER = OFF
15:53:23.465 WIF: IPv6 Global 2003:ee:712:e900:2ebc:bbff:fed7:4690
15:53:23.466 WIF: IPv6 Global fd6d:e2b:6d00:0:2ebc:bbff:fed7:4690
15:53:24.997 APP: Boot Count 93
15:53:25.010 MQT: tele/tasmota_nous_002/STATE = {"Time":"2026-01-08T15:53:24","Uptime":"0T00:00:09","UptimeSec":9,"Heap":215,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":19,"MqttCount":1,"POWER":"OFF","PWM":{"PWM1":0},"Wifi":{"AP":1,"SSId":"FBDG","BSSId":"0C:72:74:3E:71:D9","Channel":1,"Mode":"HE20","RSSI":86,"Signal":-57,"LinkCount":1,"Downtime":"0T00:00:03"}}

[arendst]

Thx. Alas there is no useful info in the log.

As there is no filesystem support in safeboot mode due to tight code space there is no file log.

I hope you're able to do the test with the solo1 binary...

[wjohn007]

the results when using tasmota32solo1.bin

otaurl http://ota.tasmota.com/tasmota32/tasmota32solo1.bin
upload 1

10:10:13.368 CMD: upload 1
10:10:13.370 SRC: WebConsole from 192.168.178.216
10:10:13.371 CMD: Grp 0, Cmd 'UPLOAD', Idx 1, Len 1, Pld 1, Data '1'
10:10:13.376 MQT: stat/tasmota_nous_002/RESULT = {"Upload":"Version 15.0.1 from http://ota.tasmota.com/tasmota32/tasmota32solo1.bin"}
00:00:00.003 HDW: ESP32-U4WDH-D v3.1 
00:00:00.006 CFG: Loaded from NVS, Count 256
00:00:00.007 CFG: CR 428/699, Busy 0
00:00:00.011 Project tasmota - tasmota-nous-002 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)
00:00:00.011 WARNING This version does not support persistent settings
00:00:00.271 WIF: Checking connection...
00:00:00.272 WIF: Attempting connection...
00:00:01.003 WIF: Connecting to AP1 FBDG Channel 1 BSSId 0C:72:74:3E:71:D9 in mode HE20 as tasmota-nous-002-1680...
00:00:02.068 WIF: IPv4 192.168.178.115, mask 255.255.255.0, gateway 192.168.178.1
00:00:02.872 WIF: Checking connection...
00:00:02.873 WIF: Connected
00:00:03.022 NTP: Sync time...
00:00:03.052 WIF: DNS resolved '2.pool.ntp.org' (90.187.112.137) in 30 ms
00:00:03.100 RTC: UTC 2026-01-09T09:10:19Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
10:10:19.000 RTC: Synced by NTP
10:10:19.057 OTA: Propagating upload
10:10:19.059 HTP: Web server active on tasmota-nous-002-1680 with IP address 192.168.178.115
10:10:19.365 WIF: IPv6 Local fe80::2ebc:bbff:fed7:4690%st1
10:10:20.159 MQT: Attempting connection...
10:10:20.173 WIF: DNS resolved 'cubietruck' (192.168.178.116) in 13 ms
10:10:20.225 MQT: Connected
10:10:20.230 MQT: tele/tasmota_nous_002/LWT = Online (retained)
10:10:20.233 MQT: cmnd/tasmota_nous_002/POWER = 
10:10:20.233 MQT: Subscribe to cmnd/tasmota_nous_002/#
10:10:20.234 MQT: Subscribe to cmnd/tasmotas/#
10:10:20.235 MQT: Subscribe to cmnd/DVES_D74690_fb/#
10:10:20.237 MQT: tele/tasmota_nous_002/INFO1 = {"Info1":{"Module":"Nous A8T","Version":"15.0.1(release-safeboot)single-core","FallbackTopic":"cmnd/DVES_D74690_fb/","GroupTopic":"cmnd/tasmotas/"}}
10:10:20.250 MQT: tele/tasmota_nous_002/INFO2 = {"Info2":{"WebServerMode":"Admin","Hostname":"tasmota-nous-002-1680","IPAddress":"192.168.178.115","IP6Global":"","IP6Local":"fe80::2ebc:bbff:fed7:4690%st1"}}
10:10:20.272 MQT: tele/tasmota_nous_002/INFO3 = {"Info3":{"RestartReason":"Software reset CPU","BootCount":98}}
10:10:20.285 MQT: stat/tasmota_nous_002/RESULT = {"POWER":"OFF"}
10:10:20.294 MQT: stat/tasmota_nous_002/POWER = OFF
10:10:23.465 WIF: IPv6 Global 2003:ee:712:e900:2ebc:bbff:fed7:4690
10:10:23.466 WIF: IPv6 Global fd6d:e2b:6d00:0:2ebc:bbff:fed7:4690
10:10:24.407 UPL: http://ota.tasmota.com/tasmota32/tasmota32solo1.bin 15.0.1(release-safeboot)
10:10:25.969 OTA: Connected in 111 ms, stack low mark 4952
10:11:01.890 APP: Boot Count 98
10:11:01.900 MQT: tele/tasmota_nous_002/STATE = {"Time":"2026-01-09T10:11:01","Uptime":"0T00:00:46","UptimeSec":46,"Heap":214,"SleepMode":"Dynamic","Sleep":50,"LoadAvg":19,"MqttCount":1,"POWER":"OFF","PWM":{"PWM1":0},"Wifi":{"AP":1,"SSId":"FBDG","BSSId":"0C:72:74:3E:71:D9","Channel":1,"Mode":"HE20","RSSI":82,"Signal":-59,"LinkCount":1,"Downtime":"0T00:00:03"}}
10:11:04.020 MQT: stat/tasmota_nous_002/UPGRADE = {"Upgrade":"Successful. Restarting"}

00:00:00.002 HDW: ESP32-U4WDH-D v3.1 
00:00:00.005 CFG: Loaded from NVS, Count 257
00:00:00.007 CFG: CR 428/699, Busy 0
00:00:00.010 Project tasmota - tasmota-nous-002 Version 15.0.1(release-safeboot)-3_1_3(2025-06-14T10:32:59)
00:00:00.010 WARNING This version does not support persistent settings
00:00:00.271 WIF: Checking connection...
00:00:00.272 WIF: Attempting connection...
00:00:01.003 WIF: Connecting to AP1 FBDG Channel 1 BSSId 0C:72:74:3E:71:D9 in mode HE20 as tasmota-nous-002-1680...
00:00:01.067 WIF: IPv4 192.168.178.115, mask 255.255.255.0, gateway 192.168.178.1
00:00:02.874 WIF: Checking connection...
00:00:02.874 WIF: Connected
00:00:03.024 NTP: Sync time...
00:00:03.048 WIF: DNS resolved '2.pool.ntp.org' (90.187.112.137) in 23 ms
00:00:03.085 RTC: UTC 2026-01-09T09:11:17Z, DST 2026-03-29T02:00:00, STD 2026-10-25T03:00:00
10:11:17.000 RTC: Synced by NTP
10:11:17.055 HTP: Web server active on tasmota-nous-002-1680 with IP address 192.168.178.115
10:11:17.380 WIF: IPv6 Local fe80::2ebc:bbff:fed7:4690%st1
10:11:18.144 MQT: Attempting connection...
10:11:18.157 WIF: DNS resolved 'cubietruck' (192.168.178.116) in 12 ms
10:11:18.197 MQT: Connected
10:11:18.203 MQT: tele/tasmota_nous_002/LWT = Online (retained)
10:11:18.205 MQT: cmnd/tasmota_nous_002/POWER = 
10:11:18.206 MQT: Subscribe to cmnd/tasmota_nous_002/#
10:11:18.207 MQT: Subscribe to cmnd/tasmotas/#
10:11:18.208 MQT: Subscribe to cmnd/DVES_D74690_fb/#
10:11:18.210 MQT: tele/tasmota_nous_002/INFO1 = {"Info1":{"Module":"Nous A8T","Version":"15.0.1(release-safeboot)single-core","FallbackTopic":"cmnd/DVES_D74690_fb/","GroupTopic":"cmnd/tasmotas/"}}
10:11:18.222 MQT: tele/tasmota_nous_002/INFO2 = {"Info2":{"WebServerMode":"Admin","Hostname":"tasmota-nous-002-1680","IPAddress":"192.168.178.115","IP6Global":"","IP6Local":"fe80::2ebc:bbff:fed7:4690%st1"}}
10:11:18.244 MQT: tele/tasmota_nous_002/INFO3 = {"Info3":{"RestartReason":"Software reset CPU","BootCount":98}}
10:11:18.258 MQT: stat/tasmota_nous_002/RESULT = {"POWER":"OFF"}
10:11:18.260 MQT: stat/tasmota_nous_002/POWER = OFF
10:11:21.466 WIF: IPv6 Global 2003:ee:712:e900:2ebc:bbff:fed7:4690
10:11:21.467 WIF: IPv6 Global fd6d:e2b:6d00:0:2ebc:bbff:fed7:4690
10:11:23.011 APP: Boot Count 98

[sfromis]

What then if you issue the command Restart 3 to switch from safeboot to normal OTA?

BTW, seeing 10 seconds from "Restarting" to the first messages from Tasmota booting is longer than I'd expect, it might indicate a failing boot without the web-available logs capturing anything, and then fallback to working safeboot. In that case, outcome of doing the Restart 3 might be similar.

[arendst]

without the web-available logs

Hence we tried using filelog which failed to report anything (as file logging starts after init finishes in the main loop) as it probably restarts too early in the process detecting fast reboots:

      if (RtcReboot.fast_reboot_count > Settings->param[P_BOOT_LOOP_OFFSET] +8) {  // Restarted 10 times
        if (EspPrepSwitchPartition(0)) {             // Switch to safeboot
          RtcReboot.fast_reboot_count = 0;           // Reset for next user restart
          RtcRebootSave();
          EspRestart();                              // Restart in safeboot mode
        }
      }

EDIT1: And to my "surprise" I see the above code is added in v15.1.0 to fix situations like is happening here...

[arendst]

@wjohn007 could you pls be so kind to provide your settings file so I can load it on a test rig and see if that shines some light on the matter.

You can find the file .settings when enabling "Show hidden files"

[wjohn007]

Hi Theo,
I tried connecting the device to a different Wi-Fi network.
A few things went wrong, so I had to perform a "Fast Power Cycle Device Recovery".

After that, the upgrade worked perfectly.

Thanks so much for your great support.

John

00:00:00.002 HDW: ESP32-U4WDH-D v3.1 
00:00:00.020 UFS: FlashFS mounted with 288 kB free
00:00:00.025 CFG: Loaded from File, Count 16
00:00:00.169 QPC: Count 1
00:00:00.218 BRY: Berry initialized, RAM used 3766 bytes
00:00:00.236 CFG: Energy loaded from file
00:00:00.236 NRG: Init driver 1
00:00:00.244 Project tasmota - Tasmota Version 15.2.0(release-tasmota32)-3.3.4(2025-12-12T10:58:29)
00:00:01.000 WIF: Connecting to AP1 FBDG Channel 11 BSSId 50:E6:36:65:BA:F0 in mode HT40 as tasmota-D74690-1680...
00:00:03.701 WIF: Connected
17:53:31.026 HTP: Web server active on tasmota-D74690-1680 with IP address 192.168.178.209

[arendst]

Thx for reporting back. I expected a wrong setting somewhere so doing the recovery fixed that anyway.