Topics

GPS Troubleshooting


Mike B
 

I am starting this thread because, well my battery went dead, so I have the long wait to reacquire...and I was searching these threads and could no longer find the reference.

I know I saw some troubleshooting steps here a while ago.

First of all I pulled the battery, and it was down around half a volt...it was brand new when I put it in a couple of months ago, and the draws has pretty much been powered most of the time...so that 40 day battery life unpowered is not a thing...OR it is 40 days per battery, powered on or not.

As I remember, if you can't get satellite info, you try running it without a battery etc.

So Basil, could you refresh my memory on GPS troubleshooting?

(Mine had been working fine till maybe a day or two ago...powered up most of the time)

So now the system time is correct including date...but the time/date listed on gpsmon is 2026-02-11...and I believe this is what happens when the onboard RTC loses power...and it will correct itself eventually (24hours?)

Thanks.


Basil Gunn
 

Hi Mike,

I have 6 DRAWS hats in test. 5 are on all the time, 1 is in my truck so
gets powered on every few days. A couple of hats have been on for over a
year most of the hats have been in test for over 6 months. All hats have
CR1220 batteries. So far I haven't experienced the problem you are
describing.

I ping'ed Bryan about this and he said that the battery has around a 40
day life span if the RPi/DRAWS hat is not powered on.

Look here for commands to verify GPS
https://github.com/nwdigitalradio/n7nix/blob/master/docs/VERIFY_CONFIG.md#check-gps

If the gps is not working for some reason your RPi system time will
eventually be set by the chronyd daemon. Type the following to see the
sources chrony is using to set system time: chronyc sources

Once the gps has satellite lock the time displayed with gpsmon should be
correct as well. You should get a lock within 15 or 20 minutes IF your
gps antenna is in a reasonable place.

The easiest thing to do may be to head up to Amazon and get some new
batteries.
https://www.amazon.com/Maxell-CR1220-Lithium-Batteries-5-Pack/dp/B0014WUYWC/ref=sr_1_5

Hope this helps.
/Basil

Mike B <kf5dey@...> writes:

I am starting this thread because, well my battery went dead, so I
have the long wait to reacquire...and I was searching these threads
and could no longer find the reference.

I know I saw some troubleshooting steps here a while ago.

First of all I pulled the battery, and it was down around half a
volt...it was brand new when I put it in a couple of months ago, and
the draws has pretty much been powered most of the time...so that 40
day battery life unpowered is not a thing...OR it is 40 days per
battery, powered on or not.

As I remember, if you can't get satellite info, you try running it without a battery etc.

So Basil, could you refresh my memory on GPS troubleshooting?

(Mine had been working fine till maybe a day or two ago...powered up most of the time)

So now the system time is correct including date...but the time/date
listed on gpsmon is 2026-02-11...and I believe this is what happens
when the onboard RTC loses power...and it will correct itself
eventually (24hours?)


Mike B
 

Thanks for the quick replay Basil.

Machine has been on for over 24 hours...gps antenna in same position that previously allowed to to receive all the satellites.    Receiving no sats.  I am now going to attempt a third antenna.

Doing the Sensors command I get the following...

pi@draws:~/bin $ sensors
rpi_volt-isa-0000
Adapter: ISA adapter
in0:              N/A  
 
ads1015-i2c-1-48
Adapter: bcm2835 I2C adapter
+12V:        +13.66 V  
in5:          +2.52 V  
User ADC 1:   +0.00 V  
User ADC 2:   +0.00 V  

What is in5: and is that a good number behind it?

Mike


Basil Gunn
 

Mike,

Machine has been on for over 24 hours...gps antenna in same position
that previously allowed to to receive all the satellites. Receiving
no sats. I am now going to attempt a third antenna.
I've noticed that on some of the RPi cases I use, the case prevents the
sma connector for the GPS antenna to attach properly.
If you do not get a GPS lock in 15 or 20 minutes then power cycle, move
the antenna and try again.

Doing the Sensors command I get the following...

pi@draws:~/bin $ sensors
rpi_volt-isa-0000
Adapter: ISA adapter
in0: N/A

ads1015-i2c-1-48
Adapter: bcm2835 I2C adapter
+12V: +13.66 V
in5: +2.52 V
User ADC 1: +0.00 V
User ADC 2: +0.00 V

What is in5: and is that a good number behind it?
I have notes on the 8 pin auxiliary connector here:
https://github.com/nwdigitalradio/n7nix/blob/master/docs/DRAWS_AUX_PORT.md

in5 is GPIO pin BCM5.


Mike B
 

Well in the 'for what it is worth' category...I went back to the shipped GPS antenna...I had changed antennas because the cord was too short.

So I cobbled together some adapters and some coax to extend the cable...and the gps is now properly receiving...

I still don't know if my previously good GPS antenna is toast...or if the process of changing antennas and moving it a bit it fixed it...

I guess I will have to test again the other antenna.

Mike


 

Remember the LNA in the antenna is powered through the coax, so make sure you are not disrupting the path.

On Thu, May 21, 2020 at 8:57 AM Mike B <kf5dey@...> wrote:
Well in the 'for what it is worth' category...I went back to the shipped GPS antenna...I had changed antennas because the cord was too short.

So I cobbled together some adapters and some coax to extend the cable...and the gps is now properly receiving...

I still don't know if my previously good GPS antenna is toast...or if the process of changing antennas and moving it a bit it fixed it...

I guess I will have to test again the other antenna.

Mike



--
John D. Hays
Kingston, WA
K7VE