[Paparazzi-devel] GPS on UART5 - unable to compile

[Michal Podhradsky]

Hello Paparazzi team,

I found a possible bug in the preprocessor/compiler code. Maybe you will be able to either verify or explain this error.

Lisa M 2.0 has the default GPS port defined as UART3. When I changed in the makefile (http://github.com/paparazzi/paparazzi/blob/v4.0/conf/boards/lisa_m_2.0.makefile#L81) the GPS port to UART5, then regardless on the GPS_PORT specified in the airframe config file, I get the following error during compilation (note that we don't send any data to GPS during the flight so we can use UART1 or UART5 as they have no Tx pin assigned):
subsystems/gps/gps_ubx.c: In function 'ubxsend_cfg_rst':
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "Transmit" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'Transmit'
subsystems/gps/gps_ubx.c:288: error: pasting ")" and "SendMessage" does not give a valid preprocessing token
subsystems/gps/gps_ubx.c:288: warning: statement with no effect
subsystems/gps/gps_ubx.c:288: error: expected ';' before 'SendMessage'
make[1]: *** [/home/csois/Backup/paparazz-svn/var/Quad_LiaM2_GX3_baro/ap/subsystems/gps/gps_ubx.o] Error 1
make[1]: Leaving directory `/home/csois/Backup/paparazz-svn/sw/airborne'
make: *** [ap.compile] Error 2
make: Leaving directory `/home/csois/Backup/paparazz-svn'

Commenting out line 279 in http://github.com/paparazzi/paparazzi/blob/v4.0/sw/airborne/subsystems/gps/gps_ubx.c#L279 solves this issue (i.e. GPS_PORT can be defined as UART5 and everything works well).

The same issue occurs for Lia 1.1 board, which is basically a derivation of Lisa M 2.0.

Do you have any explanation for this behavior? What exactly is ubxsend_cfg_rst doing? I assume it is related to soft reset of GPS unit?

Regards
Michal