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px4-firmware
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Merge branch 'master' of github.com:PX4/Firmware

This commit is contained in:
Lorenz Meier 2013-12-23 16:39:12 +01:00
parent a707e8cdb3 1279b5fbf3
commit 0f0546f1b5
2 changed files with 38 additions and 9 deletions
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2
src/drivers/drv_rc_input.h
View File

@ -60,7 +60,7 @@
/**
* Maximum number of R/C input channels in the system. S.Bus has up to 18 channels.
*/
#define RC_INPUT_MAX_CHANNELS 18
#define RC_INPUT_MAX_CHANNELS 20
/**
* Input signal type, value is a control position from zero to 100

45
src/drivers/stm32/drv_hrt.c
View File

@ -338,7 +338,12 @@ static void hrt_call_invoke(void);
# define PPM_MIN_START 2500 /* shortest valid start gap */
/* decoded PPM buffer */
#define PPM_MAX_CHANNELS 12
#define PPM_MIN_CHANNELS 5
#define PPM_MAX_CHANNELS 20
/* Number of same-sized frames required to 'lock' */
#define PPM_CHANNEL_LOCK 2 /* should be less than the input timeout */
__EXPORT uint16_t ppm_buffer[PPM_MAX_CHANNELS];
__EXPORT unsigned ppm_decoded_channels = 0;
__EXPORT uint64_t ppm_last_valid_decode = 0;
@ -440,7 +445,7 @@ hrt_ppm_decode(uint32_t status)
if (status & SR_OVF_PPM)
goto error;
/* how long since the last edge? */
/* how long since the last edge? - this handles counter wrapping implicitely. */
width = count - ppm.last_edge;
ppm.last_edge = count;
@ -455,14 +460,38 @@ hrt_ppm_decode(uint32_t status)
*/
if (width >= PPM_MIN_START) {
/* export the last set of samples if we got something sensible */
if (ppm.next_channel > 4) {
for (i = 0; i < ppm.next_channel && i < PPM_MAX_CHANNELS; i++)
ppm_buffer[i] = ppm_temp_buffer[i];
/*
* If the number of channels changes unexpectedly, we don't want
* to just immediately jump on the new count as it may be a result
* of noise or dropped edges. Instead, take a few frames to settle.
*/
if (ppm.next_channel != ppm_decoded_channels) {
static unsigned new_channel_count;
static unsigned new_channel_holdoff;
ppm_decoded_channels = i;
ppm_last_valid_decode = hrt_absolute_time();
if (new_channel_count != ppm.next_channel) {
/* start the lock counter for the new channel count */
new_channel_count = ppm.next_channel;
new_channel_holdoff = PPM_CHANNEL_LOCK;
} else if (new_channel_holdoff > 0) {
/* this frame matched the last one, decrement the lock counter */
new_channel_holdoff--;
} else {
/* we have seen PPM_CHANNEL_LOCK frames with the new count, accept it */
ppm_decoded_channels = new_channel_count;
new_channel_count = 0;
}
} else {
/* frame channel count matches expected, let's use it */
if (ppm.next_channel > PPM_MIN_CHANNELS) {
for (i = 0; i < ppm.next_channel; i++)
ppm_buffer[i] = ppm_temp_buffer[i];
ppm_last_valid_decode = hrt_absolute_time();
}
}
/* reset for the next frame */