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 {
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.
*/
/* receive signal strenght indicator (RSSI). 0 = no connection, 255: perfect connection */
uint16_t rssi = 0;
#ifdef ADC_RSSI
if (r_setup_features & PX4IO_P_SETUP_FEATURES_ADC_RSSI) {
unsigned counts = adc_measure(ADC_RSSI);
if (counts != 0xffff) {
/* use 1:1 scaling on 3.3V ADC input */
unsigned mV = counts * 3300 / 4096;
/* scale to 0..253 */
rssi = mV / 13;
}
}
#endif
perf_begin(c_gather_dsm);
uint16_t temp_count = r_raw_rc_count;
bool dsm_updated = dsm_input(r_raw_rc_values, &temp_count);
if (dsm_updated) {
r_raw_rc_flags |= PX4IO_P_STATUS_FLAGS_RC_DSM;
r_raw_rc_count = temp_count & 0x7fff;
if (temp_count & 0x8000)
r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_RC_DSM11;
else
r_raw_rc_flags &= ~PX4IO_P_RAW_RC_FLAGS_RC_DSM11;
r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FRAME_DROP);
r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
}
perf_end(c_gather_dsm);
perf_begin(c_gather_sbus);
bool sbus_status = (r_status_flags & PX4IO_P_STATUS_FLAGS_RC_SBUS);
bool sbus_failsafe, sbus_frame_drop;
bool sbus_updated = sbus_input(r_raw_rc_values, &r_raw_rc_count, &sbus_failsafe, &sbus_frame_drop, PX4IO_RC_INPUT_CHANNELS);
if (sbus_updated) {
r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_SBUS;
rssi = 255;
if (sbus_frame_drop) {
r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_FRAME_DROP;
rssi = 100;
} else {
r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FRAME_DROP);
}
if (sbus_failsafe) {
r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_FAILSAFE;
rssi = 0;
} else {
r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
}
}
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, &r_page_raw_rc_input[PX4IO_P_RAW_RC_DATA]);
if (ppm_updated) {
r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_PPM;
r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FRAME_DROP);
r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_FAILSAFE);
}
perf_end(c_gather_ppm);
/* limit number of channels to allowable data size */
if (r_raw_rc_count > PX4IO_RC_INPUT_CHANNELS)
r_raw_rc_count = PX4IO_RC_INPUT_CHANNELS;
/* store RSSI */
r_page_raw_rc_input[PX4IO_P_RAW_RC_NRSSI] = rssi;
/*
* 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) {
/* record a bitmask of channels assigned */
unsigned assigned_channels = 0;
/* update RC-received timestamp */
system_state.rc_channels_timestamp_received = hrt_absolute_time();
/* do not command anything in failsafe, kick in the RC loss counter */
if (!(r_raw_rc_flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE)) {
/* update RC-received timestamp */
system_state.rc_channels_timestamp_valid = system_state.rc_channels_timestamp_received;
/* 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];
if (mapped < PX4IO_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 < PX4IO_CONTROL_CHANNELS; i++) {
if (!(assigned_channels & (1 << i)))
r_rc_values[i] = 0;
}
/* set RC OK flag, as we got an update */
r_status_flags |= PX4IO_P_STATUS_FLAGS_RC_OK;
/* if we have enough channels (5) to control the vehicle, the mapping is ok */
if (assigned_channels > 4) {
r_raw_rc_flags |= PX4IO_P_RAW_RC_FLAGS_MAPPING_OK;
} else {
r_raw_rc_flags &= ~(PX4IO_P_RAW_RC_FLAGS_MAPPING_OK);
}
}
/*
* 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_received) > 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
*/
/* this kicks in if the receiver is gone or the system went to failsafe */
if (rc_input_lost || (r_raw_rc_flags & PX4IO_P_RAW_RC_FLAGS_FAILSAFE)) {
/* Clear the RC input status flag, clear manual override flag */
r_status_flags &= ~(
PX4IO_P_STATUS_FLAGS_OVERRIDE |
PX4IO_P_STATUS_FLAGS_RC_OK);
/* Mark all channels as invalid, as we just lost the RX */
r_rc_valid = 0;
/* Set the RC_LOST alarm */
r_status_alarms |= PX4IO_P_STATUS_ALARMS_RC_LOST;
}
/* this kicks in if the receiver is completely gone */
if (rc_input_lost) {
/* Set channel count to zero */
r_raw_rc_count = 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_LOW_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 {
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;
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();
/*
* 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) {
/* set the number of channels to zero - no inputs */
system_state.rc_channels = 0;
/* trigger an immediate report to the FMU */
system_state.fmu_report_due = true;
}
/* XXX do bypass mode, etc. here */
/* do PWM output updates */
mixer_tick();
}
}