- Mon Feb 25, 2019 4:15 am
#80793
You're actually right, it's Sigfox. Lorawan considers airtime, but in the end, I'll be getting something quite similar, like send every X seconds, no more, to avoid being mute for a certain period of time. I'm not quite sure about the ds1307, never used that part.
The problem with RTC chip is their energetic and volume cost. I eventually thought of having a retained MQTT message being replaced every second on the broker, that the ESP would get as a beacon to adjust it's drift.
villTech wrote:140 messages / day is for sigfox iirc. haven't read anything saying it's the same with lorawan. is it?
<= 1sec / 10min is your target drift for rtc. that is > 2mins per day.
What temperature are you looking at that even a less accurate DS1307 will fail to that amount?
And there are still other more accurate rtc chip.
You're actually right, it's Sigfox. Lorawan considers airtime, but in the end, I'll be getting something quite similar, like send every X seconds, no more, to avoid being mute for a certain period of time. I'm not quite sure about the ds1307, never used that part.
The problem with RTC chip is their energetic and volume cost. I eventually thought of having a retained MQTT message being replaced every second on the broker, that the ESP would get as a beacon to adjust it's drift.
