RAK8211 GPS not working

[espruino-discuss]

Posted at 2018-12-21 by a.santos

I have successfully connected to my board using the web IDE, and tried getting data from the sensors as shown in http://www.espruino.com/RAK8211

The GPS is not working as expected, when I do

require("iTracker").setGPSOn(true,print)

, I get

={
  line: ""
 }

insted of

/* { "time": "23:59:43",
  "lat": NaN, "lon": NaN,
  "fix": 0, "satellites": 0, "altitude": NaN } */

Please help me debug this issue.
Thanks!

[espruino-discuss]

Posted at 2018-12-21 by @gfwilliams

It's entirely possible you just haven't got a lock. The GPS in the RAK boards isn't assisted so it can take as much as 15 minutes to get a lock. You probably also want it by a window.

Either that or you just haven't connected a battery to it - as afaik you can interact with the device when it's just powered off 3.3v, but the GPS and cellular need a proper power source

---

Posted at 2018-12-21 by a.santos

Thanks for your quick reply,

Should I try doing

require("iTracker").setGPSOn(true,print)

and then, after 15 minutes, if I run the same code again it should show proper data?

I am powering the device using usb cable from the computer. Will that not give enough power for the GPS to function?
If not, should I connect a battery anywhere in the range of 3.3-18V to the charging interface/solar panel connector (P2)?

---

Posted at 2018-12-21 by @gfwilliams

if I run the same code again it should show proper data?

No - after having sent that code it'll just suddenly start producing data when it gets a lock.

I am powering the device using usb cable from the computer. Will that not give enough power for the GPS to function?

You're using RAK's little breakout board? If so that provides only 3.3v as far as I remember so while with the 8211's supercap USB could provide enough power, it's not actually supplying any power at all.

I'd say it's safest to attach a normal 3.7v LiPo battery to the 3 pin power plug. But you should ask RAK for this kind of support as I don't completely know their board.

---

Posted at 2019-01-04 by Kartman

I concur with Gordon - it takes some time to do a cold start. The GPS needs to download the ephemeris and at 50 bits per second, it takes some time.

---

Posted at 2019-08-12 by peruperu

I can't get any communication with the GPS module, not even waiting a long time. Instead, I can communicate with the GSM module.
Can the two modules be used simultaneously?

---

Posted at 2019-08-12 by Kartman

The nrf52832 has only one uart, so you can only talk to one device at a time - either the gps or the gsm. The gps module can take some time to get a fix - 15 minutes or so.

---

Posted at 2019-08-12 by peruperu

Ok, for switching between device but, I have wait at least one hour. You mean that the device can't send any data on the serial port until have a fix?
I have replicated a part of code in RAK8211.js but nothing...

Serial1.removeAllListeners();
Serial1.setup(9600,{tx:D9,rx:D8});
Serial1.on("data", function( data )
{
  console.log(data);
});

D10.set();

Other GPS device send data always to serial port.
Power is attached to battery input and is a 2A.

---

Posted at 2019-08-12 by Kartman

When enabled, the gps module will send data regularly. The messages it sends will tell you its status.