2025-04-23 1:51 AM - last edited on 2025-04-23 4:45 AM by Peter BENSCH
Hi Community,
I have been approaching the GNSS theory and the TESEO Hardware for few weeks and many questions come into my mind regarding the Hot Start and the Cold Start.
First things first, I am using a custom PCB on whom surface the TESEO, LTE modules and other stuff are mounted; this custom application is not provided of a back-up battery.
So my question is: May I expect a Hot Start / Warm Start even if the device is not provided of a back-up battery or it will experience a cold start every time the circuit is rebooted ?
Given the aforementioned conditions, does the possibility to save the ephemeris on the built-in flash memory in order to have a hot start exist ?
Thank you in advance for your precious help.
2025-05-14 10:32 AM
Hi Carlo,
It depends on the time on how long the board has been powered OFF.
If it is within a few minutes you can expect a HOT to a WARM start. This all depends on if the ephemeris that the GNSS receiver managed to download the time it has been ON has expired or not. If it has expired longer start times approaching WARM start can be experienced. If it has not expired, then times closer to HOT start can be expected.
If OFF for a few hours, you can expect a COLD start.
Our ephemeris gets saved in flash.
However, if you can provide power to VBAT and set the module in STANDBY, you can experience HOT start, Our standby current is ~ 10 uA.