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Diffstat (limited to 'apps/px4io/controls.c')
| -rw-r--r-- | apps/px4io/controls.c | 184 |
1 files changed, 184 insertions, 0 deletions
diff --git a/apps/px4io/controls.c b/apps/px4io/controls.c new file mode 100644 index 000000000..169d5bb81 --- /dev/null +++ b/apps/px4io/controls.c @@ -0,0 +1,184 @@ +/**************************************************************************** + * + * Copyright (C) 2012 PX4 Development Team. All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in + * the documentation and/or other materials provided with the + * distribution. + * 3. Neither the name PX4 nor the names of its contributors may be + * used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS + * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT + * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS + * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE + * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, + * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, + * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS + * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED + * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN + * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE + * POSSIBILITY OF SUCH DAMAGE. + * + ****************************************************************************/ + +/** + * @file controls.c + * + * R/C inputs and servo outputs. + */ + + +#include <nuttx/config.h> +#include <stdio.h> +#include <stdbool.h> +#include <fcntl.h> +#include <unistd.h> +#include <debug.h> +#include <stdlib.h> +#include <errno.h> +#include <termios.h> +#include <string.h> +#include <poll.h> + +#include <nuttx/clock.h> + +#include <drivers/drv_hrt.h> +#include <systemlib/hx_stream.h> +#include <systemlib/perf_counter.h> +#include <systemlib/ppm_decode.h> + +#define DEBUG +#include "px4io.h" + +#define RC_FAILSAFE_TIMEOUT 2000000 /**< two seconds failsafe timeout */ +#define RC_CHANNEL_HIGH_THRESH 1700 +#define RC_CHANNEL_LOW_THRESH 1300 + +static void ppm_input(void); + +void +controls_main(void) +{ + struct pollfd fds[2]; + + /* DSM input */ + fds[0].fd = dsm_init("/dev/ttyS0"); + fds[0].events = POLLIN; + + /* S.bus input */ + fds[1].fd = sbus_init("/dev/ttyS2"); + fds[1].events = POLLIN; + + for (;;) { + /* run this loop at ~100Hz */ + poll(fds, 2, 10); + + /* + * Gather R/C control inputs from supported sources. + * + * Note that if you're silly enough to connect more than + * one control input source, they're going to fight each + * other. Don't do that. + */ + bool locked = false; + + /* + * Store RC channel count to detect switch to RC loss sooner + * than just by timeout + */ + unsigned rc_channels = system_state.rc_channels; + + if (fds[0].revents & POLLIN) + locked |= dsm_input(); + + if (fds[1].revents & POLLIN) + locked |= sbus_input(); + + /* + * If we don't have lock from one of the serial receivers, + * look for PPM. It shares an input with S.bus, so there's + * a possibility it will mis-parse an S.bus frame. + * + * XXX each S.bus frame will cause a PPM decoder interrupt + * storm (lots of edges). It might be sensible to actually + * disable the PPM decoder completely if we have an alternate + * receiver lock. + */ + if (!locked) + ppm_input(); + + /* check for manual override status */ + if (system_state.rc_channel_data[4] > RC_CHANNEL_HIGH_THRESH) { + /* force manual input override */ + system_state.mixer_manual_override = true; + + } else { + /* override not engaged, use FMU */ + system_state.mixer_manual_override = false; + } + + /* + * If we haven't seen any new control data in 200ms, assume we + * have lost input and tell FMU. + */ + if ((hrt_absolute_time() - system_state.rc_channels_timestamp) > 200000) { + + if (system_state.rc_channels > 0) { + /* + * If the RC signal status (lost / present) has + * just changed, request an update immediately. + */ + system_state.fmu_report_due = true; + } + + /* set the number of channels to zero - no inputs */ + system_state.rc_channels = 0; + } + + /* + * PWM output updates are performed in addition on each comm update. + * the updates here are required to ensure operation if FMU is not started + * or stopped responding. + */ + mixer_tick(); + } +} + +static void +ppm_input(void) +{ + /* + * Look for new PPM input. + */ + if (ppm_last_valid_decode != 0) { + + /* avoid racing with PPM updates */ + irqstate_t state = irqsave(); + + /* PPM data exists, copy it */ + system_state.rc_channels = ppm_decoded_channels; + + for (unsigned i = 0; i < ppm_decoded_channels; i++) { + system_state.rc_channel_data[i] = ppm_buffer[i]; + } + + /* copy the timestamp and clear it */ + system_state.rc_channels_timestamp = ppm_last_valid_decode; + ppm_last_valid_decode = 0; + + irqrestore(state); + + /* trigger an immediate report to the FMU */ + system_state.fmu_report_due = true; + } +} |