diff --git a/ArduPlane/failsafe.pde b/ArduPlane/failsafe.pde new file mode 100644 index 0000000000..7b300800f7 --- /dev/null +++ b/ArduPlane/failsafe.pde @@ -0,0 +1,45 @@ +// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*- +/* + failsafe support + Andrew Tridgell, December 2011 + */ + +/* + our failsafe strategy is to detect main loop lockup and switch to + passing inputs straight from the RC inputs to RC outputs. + */ + +/* + this failsafe_check function is called from the core timer interrupt + at 1kHz. + */ +void failsafe_check(uint32_t tnow) +{ + static uint16_t last_mainLoop_count; + static uint32_t last_timestamp; + static bool in_failsafe; + + if (mainLoop_count != last_mainLoop_count) { + // the main loop is running, all is OK + last_mainLoop_count = mainLoop_count; + last_timestamp = tnow; + in_failsafe = false; + return; + } + + if (tnow - last_timestamp > 200000) { + // we have gone at least 0.2 seconds since the main loop + // ran. That means we're in trouble, or perhaps are in + // an initialisation routine or log erase. Start passing RC + // inputs through to outputs + in_failsafe = true; + } + + if (in_failsafe && tnow - last_timestamp > 20000) { + // pass RC inputs to outputs every 20ms + last_timestamp = tnow; + for (uint8_t ch=0; ch<8; ch++) { + APM_RC.OutputCh(ch, APM_RC.InputCh(ch)); + } + } +} diff --git a/ArduPlane/system.pde b/ArduPlane/system.pde index 638f7b8de7..1e98d005b6 100644 --- a/ArduPlane/system.pde +++ b/ArduPlane/system.pde @@ -46,6 +46,9 @@ MENU(main_menu, THISFIRMWARE, main_menu_commands); // the user wants the CLI. It never exits static void run_cli(void) { + // disable the failsafe code in the CLI + timer_scheduler.set_failsafe(NULL); + while (1) { main_menu.run(); } @@ -119,9 +122,8 @@ static void init_ardupilot() // Initialize the timer scheduler to use the ISR registry. // -#if HIL_MODE != HIL_MODE_ATTITUDE timer_scheduler.init( & isr_registry ); -#endif + timer_scheduler.set_failsafe(failsafe_check); // // Check the EEPROM format version before loading any parameters from EEPROM.