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Diffstat (limited to 'src/modules/px4iofirmware/controls.c')
-rw-r--r-- | src/modules/px4iofirmware/controls.c | 332 |
1 files changed, 332 insertions, 0 deletions
diff --git a/src/modules/px4iofirmware/controls.c b/src/modules/px4iofirmware/controls.c new file mode 100644 index 000000000..dc36f6c93 --- /dev/null +++ b/src/modules/px4iofirmware/controls.c @@ -0,0 +1,332 @@ +/**************************************************************************** + * + * 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 <stdbool.h> + +#include <drivers/drv_hrt.h> +#include <systemlib/perf_counter.h> +#include <systemlib/ppm_decode.h> + +#include "px4io.h" + +#define RC_FAILSAFE_TIMEOUT 2000000 /**< two seconds failsafe timeout */ +#define RC_CHANNEL_HIGH_THRESH 5000 +#define RC_CHANNEL_LOW_THRESH -5000 + +static bool ppm_input(uint16_t *values, uint16_t *num_values); + +static perf_counter_t c_gather_dsm; +static perf_counter_t c_gather_sbus; +static perf_counter_t c_gather_ppm; + +void +controls_init(void) +{ + /* DSM input */ + dsm_init("/dev/ttyS0"); + + /* S.bus input */ + sbus_init("/dev/ttyS2"); + + /* default to a 1:1 input map, all enabled */ + for (unsigned i = 0; i < MAX_CONTROL_CHANNELS; i++) { + unsigned base = PX4IO_P_RC_CONFIG_STRIDE * i; + + r_page_rc_input_config[base + PX4IO_P_RC_CONFIG_OPTIONS] = 0; + r_page_rc_input_config[base + PX4IO_P_RC_CONFIG_MIN] = 1000; + r_page_rc_input_config[base + PX4IO_P_RC_CONFIG_CENTER] = 1500; + r_page_rc_input_config[base + PX4IO_P_RC_CONFIG_MAX] = 2000; + r_page_rc_input_config[base + PX4IO_P_RC_CONFIG_DEADZONE] = 30; + r_page_rc_input_config[base + PX4IO_P_RC_CONFIG_ASSIGNMENT] = i; + r_page_rc_input_config[base + PX4IO_P_RC_CONFIG_OPTIONS] = PX4IO_P_RC_CONFIG_OPTIONS_ENABLED; + } + + c_gather_dsm = perf_alloc(PC_ELAPSED, "c_gather_dsm"); + c_gather_sbus = perf_alloc(PC_ELAPSED, "c_gather_sbus"); + c_gather_ppm = perf_alloc(PC_ELAPSED, "c_gather_ppm"); +} + +void +controls_tick() { + + /* + * 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. + */ + + perf_begin(c_gather_dsm); + bool dsm_updated = dsm_input(r_raw_rc_values, &r_raw_rc_count); + if (dsm_updated) + r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_DSM; + perf_end(c_gather_dsm); + + perf_begin(c_gather_sbus); + bool sbus_updated = sbus_input(r_raw_rc_values, &r_raw_rc_count); + if (sbus_updated) + r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_SBUS; + perf_end(c_gather_sbus); + + /* + * 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 S.bus signal. + */ + perf_begin(c_gather_ppm); + bool ppm_updated = ppm_input(r_raw_rc_values, &r_raw_rc_count); + if (ppm_updated) + r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_PPM; + perf_end(c_gather_ppm); + + ASSERT(r_raw_rc_count <= MAX_CONTROL_CHANNELS); + + /* + * In some cases we may have received a frame, but input has still + * been lost. + */ + bool rc_input_lost = false; + + /* + * If we received a new frame from any of the RC sources, process it. + */ + if (dsm_updated || sbus_updated || ppm_updated) { + + /* update RC-received timestamp */ + system_state.rc_channels_timestamp = hrt_absolute_time(); + + /* record a bitmask of channels assigned */ + unsigned assigned_channels = 0; + + /* map raw inputs to mapped inputs */ + /* XXX mapping should be atomic relative to protocol */ + for (unsigned i = 0; i < r_raw_rc_count; i++) { + + /* map the input channel */ + uint16_t *conf = &r_page_rc_input_config[i * PX4IO_P_RC_CONFIG_STRIDE]; + + if (conf[PX4IO_P_RC_CONFIG_OPTIONS] & PX4IO_P_RC_CONFIG_OPTIONS_ENABLED) { + + uint16_t raw = r_raw_rc_values[i]; + + int16_t scaled; + + /* + * 1) Constrain to min/max values, as later processing depends on bounds. + */ + if (raw < conf[PX4IO_P_RC_CONFIG_MIN]) + raw = conf[PX4IO_P_RC_CONFIG_MIN]; + if (raw > conf[PX4IO_P_RC_CONFIG_MAX]) + raw = conf[PX4IO_P_RC_CONFIG_MAX]; + + /* + * 2) Scale around the mid point differently for lower and upper range. + * + * This is necessary as they don't share the same endpoints and slope. + * + * First normalize to 0..1 range with correct sign (below or above center), + * then scale to 20000 range (if center is an actual center, -10000..10000, + * if parameters only support half range, scale to 10000 range, e.g. if + * center == min 0..10000, if center == max -10000..0). + * + * As the min and max bounds were enforced in step 1), division by zero + * cannot occur, as for the case of center == min or center == max the if + * statement is mutually exclusive with the arithmetic NaN case. + * + * DO NOT REMOVE OR ALTER STEP 1! + */ + if (raw > (conf[PX4IO_P_RC_CONFIG_CENTER] + conf[PX4IO_P_RC_CONFIG_DEADZONE])) { + scaled = 10000.0f * ((raw - conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE]) / (float)(conf[PX4IO_P_RC_CONFIG_MAX] - conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE])); + + } else if (raw < (conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE])) { + scaled = 10000.0f * ((raw - conf[PX4IO_P_RC_CONFIG_CENTER] + conf[PX4IO_P_RC_CONFIG_DEADZONE]) / (float)(conf[PX4IO_P_RC_CONFIG_CENTER] - conf[PX4IO_P_RC_CONFIG_DEADZONE] - conf[PX4IO_P_RC_CONFIG_MIN])); + + } else { + /* in the configured dead zone, output zero */ + scaled = 0; + } + + /* invert channel if requested */ + if (conf[PX4IO_P_RC_CONFIG_OPTIONS] & PX4IO_P_RC_CONFIG_OPTIONS_REVERSE) + scaled = -scaled; + + /* and update the scaled/mapped version */ + unsigned mapped = conf[PX4IO_P_RC_CONFIG_ASSIGNMENT]; + ASSERT(mapped < MAX_CONTROL_CHANNELS); + + /* invert channel if pitch - pulling the lever down means pitching up by convention */ + if (mapped == 1) /* roll, pitch, yaw, throttle, override is the standard order */ + scaled = -scaled; + + r_rc_values[mapped] = SIGNED_TO_REG(scaled); + assigned_channels |= (1 << mapped); + } + } + + /* set un-assigned controls to zero */ + for (unsigned i = 0; i < MAX_CONTROL_CHANNELS; i++) { + if (!(assigned_channels & (1 << i))) + r_rc_values[i] = 0; + } + + /* + * If we got an update with zero channels, treat it as + * a loss of input. + * + * This might happen if a protocol-based receiver returns an update + * that contains no channels that we have mapped. + */ + if (assigned_channels == 0) { + rc_input_lost = true; + } else { + /* set RC OK flag and clear RC lost alarm */ + r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_OK; + r_status_alarms &= ~PX4IO_P_STATUS_ALARMS_RC_LOST; + } + + /* + * Export the valid channel bitmap + */ + r_rc_valid = assigned_channels; + } + + /* + * If we haven't seen any new control data in 200ms, assume we + * have lost input. + */ + if (hrt_elapsed_time(&system_state.rc_channels_timestamp) > 200000) { + rc_input_lost = true; + + /* clear the input-kind flags here */ + r_status_flags &= ~( + PX4IO_P_STATUS_FLAGS_RC_PPM | + PX4IO_P_STATUS_FLAGS_RC_DSM | + PX4IO_P_STATUS_FLAGS_RC_SBUS); + } + + /* + * Handle losing RC input + */ + if (rc_input_lost) { + + /* Clear the RC input status flag, clear manual override flag */ + r_status_flags &= ~( + PX4IO_P_STATUS_FLAGS_OVERRIDE | + PX4IO_P_STATUS_FLAGS_RC_OK); + + /* Set the RC_LOST alarm */ + r_status_alarms |= PX4IO_P_STATUS_ALARMS_RC_LOST; + + /* Mark the arrays as empty */ + r_raw_rc_count = 0; + r_rc_valid = 0; + } + + /* + * Check for manual override. + * + * The PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK flag must be set, and we + * must have R/C input. + * Override is enabled if either the hardcoded channel / value combination + * is selected, or the AP has requested it. + */ + if ((r_setup_arming & PX4IO_P_SETUP_ARMING_MANUAL_OVERRIDE_OK) && + (r_status_flags & PX4IO_P_STATUS_FLAGS_RC_OK)) { + + bool override = false; + + /* + * Check mapped channel 5 (can be any remote channel, + * depends on RC_MAP_OVER parameter); + * If the value is 'high' then the pilot has + * requested override. + * + */ + if ((r_status_flags & PX4IO_P_STATUS_FLAGS_RC_OK) && (REG_TO_SIGNED(r_rc_values[4]) > RC_CHANNEL_HIGH_THRESH)) + override = true; + + if (override) { + + r_status_flags |= PX4IO_P_STATUS_FLAGS_OVERRIDE; + + /* mix new RC input control values to servos */ + if (dsm_updated || sbus_updated || ppm_updated) + mixer_tick(); + + } else { + r_status_flags &= ~PX4IO_P_STATUS_FLAGS_OVERRIDE; + } + } +} + +static bool +ppm_input(uint16_t *values, uint16_t *num_values) +{ + bool result = false; + + /* avoid racing with PPM updates */ + irqstate_t state = irqsave(); + + /* + * If we have received a new PPM frame within the last 200ms, accept it + * and then invalidate it. + */ + if (hrt_elapsed_time(&ppm_last_valid_decode) < 200000) { + + /* PPM data exists, copy it */ + *num_values = ppm_decoded_channels; + if (*num_values > MAX_CONTROL_CHANNELS) + *num_values = MAX_CONTROL_CHANNELS; + + for (unsigned i = 0; i < *num_values; i++) + values[i] = ppm_buffer[i]; + + /* clear validity */ + ppm_last_valid_decode = 0; + + /* good if we got any channels */ + result = (*num_values > 0); + } + + irqrestore(state); + + return result; +} |