fruchti/inverse_thermal_camera
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Lower clock to 48 Mhz and add thermistor averaging

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This commit is contained in:
fruchti 2018-08-04 17:01:00 +02:00
parent be01d51eff
commit 693076e37e
3 changed files with 74 additions and 59 deletions
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2
build-number.txt
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@ -1 +1 @@
220
233

23
src/ltp1245.c
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@ -40,11 +40,12 @@ static void InitStepper(void)
| (0x01 << (4 * PIN_STEPPER_BP - 32)) // Output, max. 10 MHz
;
TIM3->PSC = 72000000 / 100 / LTP1245_MAX_DRIVE_FREQ - 1;
TIM3->PSC = 48000000 / 100 / LTP1245_MAX_DRIVE_FREQ - 1;
TIM3->ARR = 100;
TIM3->DIER = TIM_DIER_UIE;
TIM3->CR1 = TIM_CR1_CEN;
NVIC_SetPriority(TIM3_IRQn, 1);
NVIC_EnableIRQ(TIM3_IRQn);
}
@ -71,7 +72,7 @@ static void InitDataLines(void)
RCC->APB1ENR |= RCC_APB1ENR_TIM2EN;
RCC->AHBENR |= RCC_AHBENR_DMA1EN;
TIM2->PSC = 720 - 1; // Each tick corresponds to ten microseconds
TIM2->PSC = 480 - 1; // Each tick corresponds to ten microseconds
TIM2->ARR = 201; // 2 milliseconds
TIM2->CCR3 = 1;
TIM2->CCR4 = 1;
@ -129,9 +130,11 @@ static void InitThermistor(void)
// Enable EOC interrupt
ADC1->CR1 = ADC_CR1_EOCIE;
NVIC_SetPriority(ADC1_2_IRQn, 7);
NVIC_EnableIRQ(ADC1_2_IRQn);
// The thermistor is connected to ADC12_IN8 (PB0)
ADC1->SQR1 = 0;
ADC1->SQR3 = (8 << ADC_SQR3_SQ1_Pos);
ADC1->SMPR2 = (7 << ADC_SMPR2_SMP8_Pos);
@ -151,7 +154,7 @@ static void InitCutter(void)
;
// Servo pulse length should be between 1 and 2 ms with a period of 20 ms
TIM4->PSC = 72 - 1; // Divide to one microsecond
TIM4->PSC = 48 - 1; // Divide to one microsecond
TIM4->ARR = 20000; // 50 Hz frequency
TIM4->CCR2 = 1000; // 1 millisecond
TIM4->CCMR1 = TIM_CCMR1_OC2M_2 | TIM_CCMR1_OC2M_1;
@ -429,6 +432,14 @@ void TIM3_IRQHandler(void)
void ADC1_2_IRQHandler(void)
{
static unsigned average = 0;
static int average_counter = 0;
average += ADC1->DR;
average_counter++;
if(average_counter == 16)
{
const int READINGS[] =
{
4095.0 * (1.0 - LTP1245_TH_REXT / (LTP1245_TH_REXT + 375.54)), // -40 °C
@ -462,7 +473,7 @@ void ADC1_2_IRQHandler(void)
4095.0 * (1.0 - LTP1245_TH_REXT / (LTP1245_TH_REXT + 1.47)) // 100 °C
};
int adc = ADC1->DR;
int adc = average / 16;
// Find first temperature higher than the measured one
int lower_entry = 0;
@ -488,6 +499,10 @@ void ADC1_2_IRQHandler(void)
// a pulse with in microseconds
PulseWidth = (285 * 178 - (int)(1000 * 178 * 0.003135) * (temp - 25))
/ (int)((5 * 1.4 - 2.9) * (5 * 1.4 - 2.9));
average_counter = 0;
average = 0;
}
}
void TIM4_IRQHandler(void)

4
src/system.c
View file

@ -12,8 +12,8 @@ void SystemInit(void)
FLASH->ACR |= FLASH_ACR_LATENCY_1;
// Set PLL to x9 (-> 72MHz system clock)
RCC->CFGR |= RCC_CFGR_PLLMULL9 | RCC_CFGR_PLLSRC | RCC_CFGR_PPRE1_2;
// Set PLL to x6 (-> 48MHz system clock)
RCC->CFGR |= RCC_CFGR_PLLMULL6 | RCC_CFGR_PLLSRC | RCC_CFGR_PPRE1_2;
// Activate PLL and wait
RCC->CR |= RCC_CR_PLLON;