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Code Issues Releases Activity

Clean up of PPM code in master.

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This commit is contained in:
James Whitlock 2011-07-19 22:06:29 +01:00 committed by Stacey Sheldon
parent 7c726f231a
commit 7ce5daef8f
1 changed files with 71 additions and 64 deletions
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131
flight/PiOS/STM32F10x/pios_ppm.c
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@ -41,19 +41,23 @@ const struct pios_rcvr_driver pios_ppm_rcvr_driver = {
.read = PIOS_PPM_Get, .read = PIOS_PPM_Get,
}; };
#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
#define PIOS_PPM_INPUT_INVALID 0
/* Local Variables */ /* Local Variables */
static TIM_ICInitTypeDef TIM_ICInitStructure; static TIM_ICInitTypeDef TIM_ICInitStructure;
static uint8_t PulseIndex; static uint8_t PulseIndex;
static uint32_t PreviousValue; static uint32_t PreviousTime;
static uint32_t CurrentValue; static uint32_t CurrentTime;
static uint32_t CapturedValue; static uint32_t DeltaTime;
static uint32_t CaptureValue[PIOS_PPM_NUM_INPUTS]; static uint32_t CaptureValue[PIOS_PPM_NUM_INPUTS];
static uint32_t CapCounter[PIOS_PPM_NUM_INPUTS]; static uint32_t LargeCounter;
static uint16_t TimerCounter;
static uint8_t supv_timer = 0; static uint8_t supv_timer = 0;
static uint8_t SupervisorState = 0; static bool Tracking;
static uint32_t CapCounterPrev[PIOS_PPM_NUM_INPUTS]; static bool Fresh;
static void PIOS_PPM_Supervisor(uint32_t ppm_id); static void PIOS_PPM_Supervisor(uint32_t ppm_id);
@ -63,10 +67,12 @@ void PIOS_PPM_Init(void)
int32_t i; int32_t i;
PulseIndex = 0; PulseIndex = 0;
PreviousValue = 0; PreviousTime = 0;
CurrentValue = 0; CurrentTime = 0;
CapturedValue = 0; DeltaTime = 0;
TimerCounter = 0; LargeCounter = 0;
Tracking = FALSE;
Fresh = FALSE;
for (i = 0; i < PIOS_PPM_NUM_INPUTS; i++) { for (i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
CaptureValue[i] = 0; CaptureValue[i] = 0;
@ -134,15 +140,6 @@ void PIOS_PPM_Init(void)
/* Enable timers */ /* Enable timers */
TIM_Cmd(pios_ppm_cfg.timer, ENABLE); TIM_Cmd(pios_ppm_cfg.timer, ENABLE);
/* Supervisor Setup */
/* Flush counter variables */
for (i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
CapCounter[i] = 0;
}
for (i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
CapCounterPrev[i] = 0;
}
/* Setup local variable which stays in this scope */ /* Setup local variable which stays in this scope */
/* Doing this here and using a local variable saves doing it in the ISR */ /* Doing this here and using a local variable saves doing it in the ISR */
TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI; TIM_ICInitStructure.TIM_ICSelection = TIM_ICSelection_DirectTI;
@ -176,56 +173,77 @@ static int32_t PIOS_PPM_Get(uint32_t rcvr_id, uint8_t channel)
*/ */
void PIOS_PPM_irq_handler(void) void PIOS_PPM_irq_handler(void)
{ {
/* Timer Overflow Interrupt
* The time between timer overflows must be greater than the PPM
* frame period. If a full frame has not decoded in the between timer
* overflows then capture values should be cleared.
*/
if (TIM_GetITStatus(pios_ppm_cfg.timer, TIM_IT_Update) == SET) { if (TIM_GetITStatus(pios_ppm_cfg.timer, TIM_IT_Update) == SET) {
TimerCounter+=pios_ppm_cfg.timer->ARR; /* Clear TIMx overflow interrupt pending bit */
TIM_ClearITPendingBit(pios_ppm_cfg.timer, TIM_IT_Update); TIM_ClearITPendingBit(pios_ppm_cfg.timer, TIM_IT_Update);
if (TIM_GetITStatus(pios_ppm_cfg.timer, pios_ppm_cfg.ccr) != SET) {
return; /* If sharing a timer with a servo output the ARR register will
} be set according to the PWM period. When timer reaches the
ARR value a timer overflow interrupt will fire. We use the
interrupt accumulate a 32-bit timer. */
LargeCounter = LargeCounter + pios_ppm_cfg.timer->ARR;
} }
/* Do this as it's more efficient */ /* Signal edge interrupt */
if (TIM_GetITStatus(pios_ppm_cfg.timer, pios_ppm_cfg.ccr) == SET) { if (TIM_GetITStatus(pios_ppm_cfg.timer, pios_ppm_cfg.ccr) == SET) {
PreviousValue = CurrentValue; PreviousTime = CurrentTime;
switch((int32_t) pios_ppm_cfg.ccr) { switch((int32_t) pios_ppm_cfg.ccr) {
case (int32_t)TIM_IT_CC1: case (int32_t)TIM_IT_CC1:
CurrentValue = TIM_GetCapture1(pios_ppm_cfg.timer); CurrentTime = TIM_GetCapture1(pios_ppm_cfg.timer);
break; break;
case (int32_t)TIM_IT_CC2: case (int32_t)TIM_IT_CC2:
CurrentValue = TIM_GetCapture2(pios_ppm_cfg.timer); CurrentTime = TIM_GetCapture2(pios_ppm_cfg.timer);
break; break;
case (int32_t)TIM_IT_CC3: case (int32_t)TIM_IT_CC3:
CurrentValue = TIM_GetCapture3(pios_ppm_cfg.timer); CurrentTime = TIM_GetCapture3(pios_ppm_cfg.timer);
break; break;
case (int32_t)TIM_IT_CC4: case (int32_t)TIM_IT_CC4:
CurrentValue = TIM_GetCapture4(pios_ppm_cfg.timer); CurrentTime = TIM_GetCapture4(pios_ppm_cfg.timer);
break; break;
} }
CurrentValue+=TimerCounter;
if(CurrentValue > 0xFFFF) {
CurrentValue-=0xFFFF;
}
/* Clear TIMx Capture compare interrupt pending bit */ /* Clear TIMx Capture compare interrupt pending bit */
TIM_ClearITPendingBit(pios_ppm_cfg.timer, pios_ppm_cfg.ccr); TIM_ClearITPendingBit(pios_ppm_cfg.timer, pios_ppm_cfg.ccr);
/* Capture computation */ /* Convert to 32-bit timer result */
if (CurrentValue > PreviousValue) { CurrentTime = CurrentTime + LargeCounter;
CapturedValue = (CurrentValue - PreviousValue);
} else {
CapturedValue = ((0xFFFF - PreviousValue) + CurrentValue);
}
/* sync pulse */ /* Capture computation */
if (CapturedValue > 8000) { DeltaTime = CurrentTime - PreviousTime;
PreviousTime = CurrentTime;
/* Sync pulse detection */
if (DeltaTime > PIOS_PPM_IN_MIN_SYNC_PULSE_US) {
Fresh = TRUE;
Tracking = TRUE;
PulseIndex = 0; PulseIndex = 0;
/* trying to detect bad pulses, not sure this is working correctly yet. I need a scope :P */ /* Valid pulse duration 0.75 to 2.5 ms*/
} else if (CapturedValue > 750 && CapturedValue < 2500) { } else if (Tracking) {
if (PulseIndex < PIOS_PPM_NUM_INPUTS) { /* Valid pulse duration 0.75 to 2.5 ms*/
CaptureValue[PulseIndex] = CapturedValue; if (DeltaTime > PIOS_PPM_IN_MIN_CHANNEL_PULSE_US
CapCounter[PulseIndex]++; && DeltaTime < PIOS_PPM_IN_MAX_CHANNEL_PULSE_US
&& PulseIndex < PIOS_PPM_NUM_INPUTS) {
CaptureValue[PulseIndex] = DeltaTime;
PulseIndex++; 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;
}
} }
} }
} }
@ -241,26 +259,15 @@ static void PIOS_PPM_Supervisor(uint32_t ppm_id) {
} }
supv_timer = 0; supv_timer = 0;
/* Simple state machine */ if (!Fresh) {
if (SupervisorState == 0) { Tracking = FALSE;
/* Save this states values */
for (int32_t i = 0; i < PIOS_PPM_NUM_INPUTS; i++) {
CapCounterPrev[i] = CapCounter[i];
}
/* Move to next state */
SupervisorState = 1;
} else {
/* See what channels have been updated */
for (int32_t i = 0; i < PIOS_PPM_NUM_INPUTS ; i++) { for (int32_t i = 0; i < PIOS_PPM_NUM_INPUTS ; i++) {
if (CapCounter[i] == CapCounterPrev[i]) { CaptureValue[PulseIndex] = PIOS_PPM_INPUT_INVALID;
CaptureValue[i] = 0;
} }
} }
/* Move to next state */ Fresh = FALSE;
SupervisorState = 0;
}
} }
#endif #endif