rooty/LibrePilot
1
0
Fork 0
mirror of https://bitbucket.org/librepilot/librepilot.git synced 2025-02-19 09:54:15 +01:00
Code Issues Releases Activity

Add in a PPM input frame size tracker.

Browse Source 
Move update of capture values to start of new frame.
Fix an issue with setting channels to invalid.
This commit is contained in:
James Whitlock 2011-07-23 01:38:51 +01:00
parent 7a58b4cceb
commit 11c568ec50
3 changed files with 52 additions and 23 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
flight/PiOS/Boards/STM32103CB_CC_Rev1.h
View File

@ -228,11 +228,6 @@ extern uint32_t pios_com_sbus_id;
#define PIOS_RCVR_MAX_DEVS 1
#define PIOS_RCVR_MAX_CHANNELS 12
//-------------------------
// Receiver PPM input
//-------------------------
#define PIOS_PPM_NUM_INPUTS 6 //Could be more if needed
//-------------------------
// Receiver PWM input
//-------------------------

6
flight/PiOS/Boards/STM3210E_OP.h
View File

@ -201,12 +201,6 @@ extern uint32_t pios_com_sbus_id;
#define PIOS_RCVR_MAX_DEVS 1
#define PIOS_RCVR_MAX_CHANNELS 12
//-------------------------
// Receiver PPM input
//-------------------------
#define PIOS_PPM_NUM_INPUTS 8 //Could be more if needed
#define PIOS_PPM_SUPV_ENABLED 1
//-------------------------
// Receiver PWM input
//-------------------------

64
flight/PiOS/STM32F10x/pios_ppm.c
View File

@ -41,6 +41,9 @@ const struct pios_rcvr_driver pios_ppm_rcvr_driver = {
.read = PIOS_PPM_Get,
};
#define PIOS_PPM_IN_MIN_NUM_CHANNELS 4
#define PIOS_PPM_IN_MAX_NUM_CHANNELS 8
#define PIOS_PPM_STABLE_CHANNEL_COUNT 25 // frames
#define PIOS_PPM_IN_MIN_SYNC_PULSE_US 7000 // microseconds
#define PIOS_PPM_IN_MIN_CHANNEL_PULSE_US 750 // microseconds
#define PIOS_PPM_IN_MAX_CHANNEL_PULSE_US 2400 // microseconds
@ -52,8 +55,12 @@ static uint8_t PulseIndex;
static uint32_t PreviousTime;
static uint32_t CurrentTime;
static uint32_t DeltaTime;
static uint32_t CaptureValue[PIOS_PPM_NUM_INPUTS];
static uint32_t CaptureValue[PIOS_PPM_IN_MAX_NUM_CHANNELS];
static uint32_t CaptureValueNewFrame[PIOS_PPM_IN_MAX_NUM_CHANNELS];
static uint32_t LargeCounter;
static int8_t NumChannels;
static int8_t NumChannelsPrev;
static uint8_t NumChannelCounter;
static uint8_t supv_timer = 0;
static bool Tracking;
@ -71,11 +78,15 @@ void PIOS_PPM_Init(void)
CurrentTime = 0;
DeltaTime = 0;
LargeCounter = 0;
NumChannels = -1;
NumChannelsPrev = -1;
NumChannelCounter = 0;
Tracking = FALSE;
Fresh = FALSE;
for (i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
for (i = 0; i < PIOS_PPM_IN_MAX_NUM_CHANNELS; i++) {
CaptureValue[i] = 0;
CaptureValueNewFrame[i] = 0;
}
NVIC_InitTypeDef NVIC_InitStructure = pios_ppm_cfg.irq.init;
@ -159,7 +170,7 @@ void PIOS_PPM_Init(void)
static int32_t PIOS_PPM_Get(uint32_t rcvr_id, uint8_t channel)
{
/* Return error if channel not available */
if (channel >= PIOS_PPM_NUM_INPUTS) {
if (channel > PIOS_PPM_IN_MAX_NUM_CHANNELS) {
return -1;
}
return CaptureValue[channel];
@ -221,25 +232,53 @@ void PIOS_PPM_irq_handler(void)
/* Sync pulse detection */
if (DeltaTime > PIOS_PPM_IN_MIN_SYNC_PULSE_US) {
if (PulseIndex == NumChannelsPrevFrame
&& PulseIndex >= PIOS_PPM_IN_MIN_NUM_CHANNELS
&& PulseIndex <= PIOS_PPM_IN_MAX_NUM_CHANNELS)
{
/* If we see n simultaneous frames of the same
number of channels we save it as our frame size */
if (NumChannelCounter < PIOS_PPM_STABLE_CHANNEL_COUNT)
NumChannelCounter++;
else
NumChannels = PulseIndex;
} else {
NumChannelCounter = 0;
}
/* Check if the last frame was well formed */
if (PulseIndex == NumChannels && Tracking) {
/* The last frame was well formed */
for (uint32_t i = 0; i < NumChannels; i++) {
CaptureValue[i] = CaptureValueNewFrame[i];
}
for (uint32_t i = NumChannels;
i < PIOS_PPM_IN_MAX_NUM_CHANNELS; i++) {
CaptureValue[i] = 0;
}
}
Fresh = TRUE;
Tracking = TRUE;
NumChannelsPrevFrame = PulseIndex;
PulseIndex = 0;
/* We rely on the supervisor to set CaptureValue to invalid
if no valid frame is found otherwise we ride over it */
} else if (Tracking) {
/* Valid pulse duration 0.75 to 2.5 ms*/
if (DeltaTime > PIOS_PPM_IN_MIN_CHANNEL_PULSE_US
&& DeltaTime < PIOS_PPM_IN_MAX_CHANNEL_PULSE_US
&& PulseIndex < PIOS_PPM_NUM_INPUTS) {
&& PulseIndex < PIOS_PPM_IN_MAX_NUM_INPUTS) {
CaptureValue[PulseIndex] = DeltaTime;
CaptureValueNewFrame[PulseIndex] = DeltaTime;
PulseIndex++;
if (PulseIndex == PIOS_PPM_NUM_INPUTS) {
PulseIndex = 0;
}
} else {
/* Not a valid pulse duration */
Tracking = FALSE;
for (uint32_t i = 0; i < PIOS_PPM_NUM_INPUTS ; i++) {
CaptureValue[PulseIndex] = PIOS_PPM_INPUT_INVALID;
for (uint32_t i = 0; i < PIOS_PPM_IN_MAX_NUM_CHANNELS ; i++) {
CaptureValueNewFrame[i] = PIOS_PPM_INPUT_INVALID;
}
}
}
@ -259,8 +298,9 @@ static void PIOS_PPM_Supervisor(uint32_t ppm_id) {
if (!Fresh) {
Tracking = FALSE;
for (int32_t i = 0; i < PIOS_PPM_NUM_INPUTS ; i++) {
CaptureValue[PulseIndex] = PIOS_PPM_INPUT_INVALID;
for (int32_t i = 0; i < PIOS_PPM_IN_MAX_NUM_CHANNELS ; i++) {
CaptureValue[i] = PIOS_PPM_INPUT_INVALID;
CaptureValueNewFrame[i] = PIOS_PPM_INPUT_INVALID;
}
}