mirror of https://github.com/ArduPilot/ardupilot
52 lines
1.5 KiB
Plaintext
52 lines
1.5 KiB
Plaintext
// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
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/*
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* failsafe support
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* Andrew Tridgell, December 2011
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*/
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/*
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* our failsafe strategy is to detect main loop lockup and switch to
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* passing inputs straight from the RC inputs to RC outputs.
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*/
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/*
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* this failsafe_check function is called from the core timer interrupt
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* at 1kHz.
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*/
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void failsafe_check(uint32_t tnow)
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{
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static uint16_t last_mainLoop_count;
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static uint32_t last_timestamp;
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static bool in_failsafe;
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if (mainLoop_count != last_mainLoop_count) {
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// the main loop is running, all is OK
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last_mainLoop_count = mainLoop_count;
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last_timestamp = tnow;
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in_failsafe = false;
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return;
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}
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if (tnow - last_timestamp > 200000) {
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// we have gone at least 0.2 seconds since the main loop
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// ran. That means we're in trouble, or perhaps are in
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// an initialisation routine or log erase. Start passing RC
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// inputs through to outputs
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in_failsafe = true;
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}
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if (in_failsafe && tnow - last_timestamp > 20000) {
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// pass RC inputs to outputs every 20ms
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last_timestamp = tnow;
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APM_RC.clearOverride();
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uint8_t start_ch = 0;
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if (demoing_servos) {
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start_ch = 1;
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}
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for (uint8_t ch=start_ch; ch<4; ch++) {
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APM_RC.OutputCh(ch, APM_RC.InputCh(ch));
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}
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RC_Channel_aux::copy_radio_in_out(RC_Channel_aux::k_manual);
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}
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}
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