[arch/linux] sys_time: get time from CLOCK_MONOTONIC
Instead of simply adding up the sys_time ticks, seconds, get current time from CLOCK_MONOTONIC and directly set sys_time from that (difference to clock monotonic time at startup).
Single udp socket
Only create one socket for sending and receiving, instead of two where you use one only to send and the other only to receive.
There should be no reason/need to create two separate ones...
Also add udp_socket.[ch] to make it easier to use only the UDP sockets without the UART like mcu_periph/udp interface around it.
Provides the functions:
- udp_socket_create
- udp_socket_send
- udp_socket_recv
- udp_socket_recv_dontwait
GPS accuracy speech less verbose
Addresses #1046
GPS accuracy is considered ok if better than 10m, very bad if worse than 20m and simply low in between.
Now only if the accuracy falls into a different range than previously reported.
Instead of simply adding up the sys_time ticks, seconds, get curent time from CLOCK_MONOTONIC and directly set sys_time from that
(difference to clock monotonic time at startup).
Since using SIGALRM to call the sys_tick_handler (via setitimer) can cause problems like interrupting some other syscalls
(i.e. read,write, ioctl), setup a separate thread and use timer_fd instead.
That is a Linux-specific set of functions that presents POSIX timers as file descriptors rather than signals.
If the thread runs with a normal priority it can happen that some timer events are missed (and hence sys_time not updated in time).
So added a function to set a higher prio for that thread (needs root rights or properly set up limits for the user).
In some simple tests no events were missed when running with prio 29 via SCHED_FIFO, even if events would be missed,
the sys_tick_handler is called the appropriate number of times (so that the time is correct again after)...
After these changes also fix some bugs discovered in the ardrone navdata reading.
Reading is now done in a separate thread which waits on a condition variable until the navdata_update event loop has copied the buffer.
[conf] remove AHRS_x_FREQUENCY defaults from imu/ahrs makefiles
As the dt is calculated from the actual timestamps by default now, and it doesn't really make that much sense to have global flags for the frequencies, simply remove the defaults....
add $(PAPARAZZI_SRC)/sw/simulator to VPATH, so that makes adds that to the search path.
This makes it possible to add NPS sources as nps/foo.c to $(TARGET).srcs,
and the object and dependency files will correctly be put into $(PAPARAZZI_HOME)/var/aircrafts/<ac>/nps/<src file>
So e.g. /home/<user>/paparazzi/var/aircrafts/Quad_LisaM_2/nps/nps/nps_main.o
While here, also generate the .d dependency files during the compilation run instead of a separate run.
fixes#798
Felix Ruess
Gautier Hattenberger