Timeline for Embedded Linux: setting the time without NTP
Current License: CC BY-SA 4.0
15 events
| when toggle format | what | by | license | comment | |
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| Feb 28, 2019 at 18:01 | vote | accept | jpsalm | ||
| Feb 26, 2019 at 23:15 | answer | added | jpsalm | timeline score: 0 | |
| Feb 26, 2019 at 19:43 | comment | added | jpsalm | Unfortunately its an external library supplied with sat module that is reading file creation dates and requesting new content as needed. Spoofing those could work if possible but having an accurate system clock would be a nice to have for logging etc. | |
| Feb 26, 2019 at 18:46 | comment | added | jpsalm | We need to synchronize the system time with that of the satellite and as the rtc is powered by a large cap, when these devices are first powered on they will be out of date. We are pulling files down from the satellite based on date hence the need for synchronization, but it is not an essential operation so delaying until next boot (with direct rtc write) would be fine. The satellite time is only available to us well into the user application being started and thus am unsure if stime() or similar commands can be used safely. | |
| Feb 26, 2019 at 18:21 | comment | added | Rui F Ribeiro | @jpsalm What is the use of writing directly to the RTC clock? It is only read at boot time. Nevertheless, it is not yet clear what you need to do and why. | |
| Feb 26, 2019 at 17:53 | history | edited | jpsalm | CC BY-SA 4.0 |
Added blurb about hwclock implemenation and why that is not an option in this case.
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| Feb 26, 2019 at 17:14 | comment | added | jpsalm | There is an rtc but our hwclock implementation doesn't have the ability to write directly to it -- only to and from the system time from what I can tell. See my comment below on the usage options for our hwclock. | |
| Feb 26, 2019 at 17:10 | review | Close votes | |||
| Feb 27, 2019 at 13:22 | |||||
| Feb 26, 2019 at 16:59 | comment | added | Rui F Ribeiro | There can be always the possibility of feeding an NTP daemon. As an example: unixwiz.net/techtips/raspberry-pi3-gps-time.html | |
| Feb 26, 2019 at 16:45 | comment | added | Rui F Ribeiro | I used to have some apps running in an iOT, and they were quite happy even if the time via NTP got later in the game. Granted that after I bought an RTC for that, things were smoother, but it all depends on what you want to do and whether time is critical for the apllicational part. | |
| Feb 26, 2019 at 16:39 | comment | added | Rui F Ribeiro | There is the RTC point of view, the system pov, and could even be the application pov....what do is necessary to do, what is needed and what exactly breaks? Could it pay out initializing the applications after getting the time if getting it on time is critical? What time resolution does the app need? And is there an RTC? | |
| Feb 26, 2019 at 16:34 | answer | added | NetIceCat | timeline score: 2 | |
| Feb 26, 2019 at 16:20 | review | First posts | |||
| Feb 26, 2019 at 16:22 | |||||
| Feb 26, 2019 at 16:19 | history | edited | Jeff Schaller♦ |
edited tags
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| Feb 26, 2019 at 16:15 | history | asked | jpsalm | CC BY-SA 4.0 |