Hardware Watchdog

Hi
My unit gives itself a restart every day or so for reasons which escape me. It sends data to both PVOUTPUT and EMONCMS when it’s up and apart from the restart, monitors very nicely.
Any clues as to what the Hardware watchdog is barking at?
** Restart **

SD initialized.
4/07/20 10:05:40z Real Time Clock is running. Unix time 1586253940
4/07/20 10:05:40z Reset reason: Hardware Watchdog
4/07/20 10:05:40z Trace: 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:2, 18:3, 18:4, 18:5, 1:6, 1:3, 1:4, 1:5[21], 21:0, 21:1, 21:10
4/07/20 10:05:40z ESP8266 ChipID: 6144641
4/07/20 10:05:40z IoTaWatt 5.0, Firmware version 02_05_02
4/07/20 10:05:40z SPIFFS mounted.
4/07/20 20:05:41 Local time zone: +10:00
4/07/20 20:05:41 Using Daylight Saving Time (BST) when in effect.
4/07/20 20:05:41 device name: IotaWatt
4/07/20 20:05:41 MDNS responder started for hostname IotaWatt
4/07/20 20:05:41 LLMNR responder started for hostname IotaWatt
4/07/20 20:05:41 HTTP server started
4/07/20 20:05:41 timeSync: service started.
4/07/20 20:05:41 statService: started.
4/07/20 20:05:41 dataLog: service started.
4/07/20 20:05:42 dataLog: Last log entry 04/07/20 20:05:30
4/07/20 20:05:43 WiFi connected. SSID=Frog, IP=192.168.0.31, channel=6, RSSI -55db
4/07/20 20:05:43 Updater: service started. Auto-update class is MINOR
4/07/20 20:05:46 EmonService: started. url:80=emoncms.org, node=IotaWatt, interval=10
4/07/20 20:05:48 Updater: Auto-update is current for class MINOR.
4/07/20 20:05:48 EmonService: Start posting at 04/07/20 20:05:30
4/07/20 20:06:41 historyLog: service started.
4/07/20 20:06:41 historyLog: Last log entry 04/07/20 20:05:00
4/07/20 20:06:41 PVoutput: started
4/07/20 20:08:05 PVoutput: System Wally’s Shed, interval 5, freeload mode
4/07/20 20:08:06 PVoutput: Start status beginning 04/07/20 20:05:00

** Restart **

SD initialized.
4/08/20 08:44:10z Real Time Clock is running. Unix time 1586335450
4/08/20 08:44:10z Reset reason: Hardware Watchdog
4/08/20 08:44:10z Trace: 1:6, 1:3, 1:4, 1:5[3], 3:0, 3:11, 1:6, 1:1[3], 1:2[4], 9:0[4], 9:0, 9:1, 8:4, 8:6, 8:8, 8:9, 9:3, 9:5, 9:9, 1:2, 1:3, 1:4, 1:5[3], 3:0, 3:11, 1:6, 1:3, 1:4, 1:5[21], 21:0, 21:1, 21:10
4/08/20 08:44:10z ESP8266 ChipID: 6144641
4/08/20 08:44:10z IoTaWatt 5.0, Firmware version 02_05_02
4/08/20 08:44:10z SPIFFS mounted.
4/08/20 18:44:11 Local time zone: +10:00
4/08/20 18:44:11 Using Daylight Saving Time (BST) when in effect.
4/08/20 18:44:11 device name: IotaWatt
4/08/20 18:44:11 MDNS responder started for hostname IotaWatt
4/08/20 18:44:11 LLMNR responder started for hostname IotaWatt
4/08/20 18:44:11 HTTP server started
4/08/20 18:44:11 timeSync: service started.
4/08/20 18:44:11 statService: started.
4/08/20 18:44:11 dataLog: service started.
4/08/20 18:44:12 dataLog: Last log entry 04/08/20 18:44:00
4/08/20 18:44:12 WiFi connected. SSID=Frog, IP=192.168.0.31, channel=6, RSSI -52db
4/08/20 18:44:12 Updater: service started. Auto-update class is MINOR
4/08/20 18:44:16 EmonService: started. url:80=emoncms.org, node=IotaWatt, interval=10
4/08/20 18:44:18 EmonService: Start posting at 04/08/20 18:44:10
4/08/20 18:44:19 Updater: Auto-update is current for class MINOR.
4/08/20 18:45:11 historyLog: service started.
4/08/20 18:45:11 historyLog: Last log entry 04/08/20 18:44:00
4/08/20 18:45:11 PVoutput: started
4/08/20 18:45:12 PVoutput: System Wally’s Shed, interval 5, freeload mode
4/08/20 18:45:12 PVoutput: Start status beginning 04/08/20 18:40:00
4/09/20 09:37:09 EmonService: HTTP response 302, retrying.
4/09/20 09:39:29 EmonService: Retry successful after 40 attempts.

While the trace is not conclusive, it points to heap problems. Release 02_05_07 contains a lot of improvements to stabilize heap usage, both in the firmware and in the newer core. That release is in ALPA and BETA auto-update right now, and barring any new issues, should advance to MINOR in several weeks. If the problem persists after that, please post back. In the meantime, as you note, the daily restart is a fairly minor inconvenience that literally takes a few seconds.