I am trying to use a ORG-1411 GPS (https://origingps.com/products/hornet-org1411/) to get location and UTC fix, using the breakout from Mikroe (https://www.mikroe.com/nano-gps-click). To parse the readings I am using ublox ucenter (https://www.u-blox.com/en/product/u-center) and sometimes I also use TinyGPS+ library for the Arduino.
The TTFF was around 5 minutes for location and 10 seconds for UTC time the first time I turned on the GPS from cold start. I expect the fix time to be lower (< 35 seconds) as claimed by Origin for the subsequent cold starts (https://origingps.com/wp-content/uploads/2019/09/Nano-Hornet-ORG1411-Datasheet-Rev-4.3.pdf). However, the GPS takes the same amount of time to get the location and time data from satellites. I tested the module in two locations out in the open with open sky above and no surrounding buildings within close proximity.
Can anyone suggest what's wrong?
Best Answer
The first thing that comes to my mind is that a first fix starts with unknown position and with unknown time. The device has to find as much satellites and then calculate the position.
All the subsequent fixes are easier to find, because you already have an approximate positon and you already have the correct time, then a GPS tracker would spend less time to lock in, by doing a Cross-correlation of known sattelite sequence and received signal. But in case the initial conditons are not met (no approximate position or no correct time) it has to do the first fix, every startup.
Make sure you have a battery backed RTC time and position, and a kind of mechanism to upload the initial conditions to the GPS receiver at startup.
EDIT:
Looking at datasheet, the SoC has a BBRAM - Battery Backed RAM, but there s no mention about the battery neither it has any pad to connect an external battery. Probably it has an super capacitor or small LiPo battery embedded in the module. It could be that this battery is empty, since it is new device. Try to power the device for couple of hours or the entire day, because that battery would charge very slowly.
Once it will be charged try to see if the fix comes within specific time.
EDIT 2: I think I have found the root of the problem read this:
17.2. POWER SUPPLY It is recommended to keep the power supply on all the time in order to maintain RTC block active and keep satellite data in RAM for fastest possible TTFF. When VCC is removed settings are reset to factory default and the receiver performs Cold Start on next power up.