Daniel

My remote #HeltecV4 #MeshCore solar repeater has a clock drift of about 20+ minutes after a week already.

On meshcore v1.14 with powersaving on. Tried clkreboot and synced clock already; second week and just happened again.

Anyone else experiencing massive clock drift on their heltec v4?

Mar 16 at 8:54pmWeb
Show threadcrepererumMar 16
@djh is the clock quartz driven or is this just a silicon oscillation? My guess would be that the solar power voltage fluctuates quite a bit, which may mess way more than the usual USB or battery power supply, especially without external NTP clock source
Show threadcrepererumMar 16
@djh actually googling "ESP32S3 RTC" (for real time clock) shows a bunch of complaints. My guess is that the board didn't bother to solder on a crystal.
Show threadcrepererumMar 16
@djh you could wire up an external RTC, something like this
https://how2electronics.com/esp32-ds3231-based-real-time-clock/
ESP32 & DS3231 Based Real Time Clock (RTC) on OLED

In this project, we will interface Real-Time Clock (RTC) Module DS3231 with ESP32 Board and display the Time and Date value on 0.96" OLED Display.

How To Electronics
Show threadDanielMar 17

@crepererum The heltec v4 is connected to the batteries via a solar power management board like this

https://chaos.social/@djh/116022593822272837

I'm just wondering if other people see the same behavior with their setup; 20m drift after a few days is quite a lot.

Next to debug is to turn off the powersaving mode and see if that changes anything. I don't have physical access to this repeater often.

Daniel (@[email protected])

Attached: 1 image See you tonight at @xHain_hackspace for #OpenComs 📻 #MeshCore #Berlin #xhain

chaos.social
Show threadcrepererumMar 17
@djh another thought: could it have lost power completely at some point so that the time after waking up is "old" (= the last state before loosing power)?
Show threadDanielMar 17
@crepererum but it's going 20m too fast 🤔 the batteries I use should be able to power it for at least two weeks, and it's also sunny these days 🌞
Show threadcrepererumMar 17
@djh do you have metrics / monitoring?
Show threadDaniel6d ago
@crepererum aha! https://github.com/meshcore-dev/MeshCore/pull/1350
Show threadcrepererum6d ago
@djh so you're "no internet" decentralized grassroot network now depends on the satellite system of the US military? 🤷
Show threadDaniel5d ago

@crepererum Or EU's Galileo equivalent; but yeap not a good approach to simply sync a clock.

The GPS module is also power hungry, not something I want on my solar powered repeater.

Other options could be

1. add dedicated hardware RTC module

2. implement distributed clock sync

Show threadHoward GeesMar 19
@djh You've prompted me to check my solar Meshcore repeater running on a Heltec v4.
Two weeks and no drift in time - clock is working fine.
Show threadDanielMar 19
@HowardGees Thank you for checking! Can you confirm that you have "powersaving on" configured? I'm trying to figure out what could cause this 🤔
Show threadHoward GeesMar 19

@djh I didn't even know there was a power saving option! Where is that hiding?

Running a 10000mAh battery and 12w solar panel (more like 8w actual performance).

Show threadDanielMar 19

@HowardGees Check this out for repeater config options:

https://github.com/meshcore-dev/MeshCore/wiki/Repeater-&-Room-Server-CLI-Reference

The powersaving feature is described at the end. I believe it's only usable from v1.14+ onwards for the heltec v4.

I'm setting it like this via serial

set tx 17
powersaving on

For the tx x power relationship see
https://chaos.social/@djh/116186281960690673

Repeater & Room Server CLI Reference

A new lightweight, hybrid routing mesh protocol for packet radios - meshcore-dev/MeshCore

GitHub
Show threadHoward GeesMar 19
@djh Not seen this. I'll check next time I'm in range of that repeater. However I do know the transmission power was set to 18.