GPS Sample code works, but how do you reduce power?

[stevenminnick]

I got this project to compile and work: https://github.com/NordicPlayground/fw-nrfconnect-nrf/tree/master/samples/nrf9160/gps

I have the latest radio firmware at this time: 0.7.0_29.  I'm actually using a DK 0.8.2 which required an external antenna, but when I use one it works fine.

I measure constant current around 30mA when doing this. 

According to this, there seems to be 2 lower power modes below what this sample is using: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf9160%2F_tmp%2Falta.nRF9160%2Fautodita%2FCURRENT%2Fparameters.id_current_gps.html&resultof=%22%67%70%73%22%20%22%67%70%22%20

Also some information on lower power modes here: https://infocenter.nordicsemi.com/index.jsp?topic=%2Fps_nrf9160%2Fgps.html&resultof=%22%67%70%73%22%20%22%67%70%22%20

Is there any guidance on getting the radio into these lower power modes?  Are these modes implemented in the radio firmware at this time?

[Martin Lesund]

Hi steven,

Please share screenshots/logs etc. of what is going wrong.

[stevenminnick]

I had the nrf branch switched over to the main 1.0 one for a while but I switched over to the example referenced above and get this when I tried to open the project. 

[stevenminnick]

That was the ns version.  When I try to select the non ns version I get a different error

CMakeOutput.log

The target system is: Generic - 1.14.99 - arm
The host system is: Windows - 10.0.17134 - AMD64
Compiling the C compiler identification source file "CMakeCCompilerId.c" succeeded.
Compiler: C:/gnuarmemb/bin/arm-none-eabi-gcc.exe 
Build flags: 
Id flags: -c 

The output was:
0


Compilation of the C compiler identification source "CMakeCCompilerId.c" produced "CMakeCCompilerId.o"

The C compiler identification is GNU, found in "C:/git/nRF/ncs/nrf/applications/asset_tracker/build_nrf9160_pca10090ns/CMakeFiles/3.13.2/CompilerIdC/CMakeCCompilerId.o"

Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" succeeded.
Compiler: C:/gnuarmemb/bin/arm-none-eabi-gcc.exe 
Build flags: 
Id flags: -c 

The output was:
0


Compilation of the CXX compiler identification source "CMakeCXXCompilerId.cpp" produced "CMakeCXXCompilerId.o"

The CXX compiler identification is GNU, found in "C:/git/nRF/ncs/nrf/applications/asset_tracker/build_nrf9160_pca10090ns/CMakeFiles/3.13.2/CompilerIdCXX/CMakeCXXCompilerId.o"

Checking whether the ASM compiler is GNU using "--version" matched "(GNU assembler)|(GCC)|(Free Software Foundation)":
arm-none-eabi-gcc.exe (GNU Tools for Arm Embedded Processors 7-2018-q2-update) 7.3.1 20180622 (release) [ARM/embedded-7-branch revision 261907]
Copyright (C) 2017 Free Software Foundation, Inc.
This is free software; see the source for copying conditions.  There is NO
warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

Performing C SOURCE FILE Test toolchain_is_ok succeeded with the following output:
Change Dir: C:/git/nRF/ncs/nrf/applications/asset_tracker/build_nrf9160_pca10090ns/CMakeFiles/CMakeTmp

Run Build Command:"C:/ProgramData/chocolatey/bin/ninja.exe" "cmTC_8d7d6"
[1/2] Building C object CMakeFiles/cmTC_8d7d6.dir/src.c.obj

[2/2] Linking C executable cmTC_8d7d6

c:/gnuarmemb/bin/../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/bin/ld.exe: warning: cannot find entry symbol _start; defaulting to 00008000


Source file was:
int main(void) { return 0; }

CMakeError.log

Compiling the C compiler identification source file "CMakeCCompilerId.c" failed.
Compiler: C:/gnuarmemb/bin/arm-none-eabi-gcc.exe 
Build flags: 
Id flags:  

The output was:
1
c:/gnuarmemb/bin/../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/lib\libc.a(lib_a-exit.o): In function `exit':
exit.c:(.text.exit+0x2c): undefined reference to `_exit'
collect2.exe: error: ld returned 1 exit status


Compiling the CXX compiler identification source file "CMakeCXXCompilerId.cpp" failed.
Compiler: C:/gnuarmemb/bin/arm-none-eabi-gcc.exe 
Build flags: 
Id flags:  

The output was:
1
c:/gnuarmemb/bin/../lib/gcc/arm-none-eabi/7.3.1/../../../../arm-none-eabi/lib\libc.a(lib_a-exit.o): In function `exit':
exit.c:(.text.exit+0x2c): undefined reference to `_exit'
collect2.exe: error: ld returned 1 exit status