mirror of https://github.com/ArduPilot/ardupilot
47 lines
1.3 KiB
Plaintext
47 lines
1.3 KiB
Plaintext
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// -*- 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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for (uint8_t ch=0; ch<8; ch++) {
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APM_RC.OutputCh(ch, APM_RC.InputCh(ch));
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}
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}
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}
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