When I run this code on my STM32L1 board, the debugger hangs once it reaches to a Float (in this case the variable 'Distance') or Delay, I mean it seems like it's processing, however it never goes through, and I have to close it and run the debugger again, which hangs of course again. Note that the code builds without errors or warnings. Is there's any special configuration for float ?
The following is the related part of the code:
void Delay(int x){ //input milliseconds, delay that number of milliseconds int a,b; for(a=0; a<x; a++){ for(b=0; b<1000; b++){ } } } . . . volatile int timespan = 0; // Total pulse width int main(void){ float Distance; // actual distance in cm . . . while(1){ TIM4_Echo_Read(); Distance = (timespan / 58.0); if (Distance <= 100){ GPIOB->BSRRL = (1<<7); } else { GPIOB->BSRRH = (1<<7); } Delay(10); }
timespan is declared as a global int. Note that none of this happens when I declare Distance as int instead of float.
Any idea why the debugger keeps getting stuck on float instructions?
>> the only option I have is either to stop (by pressing the red icon) or reset.
And the question asked was WHERE does it STOP. The details and specifics are important to understand what has happened.
Make sure the stack is sufficiently large, and that the flash has the correct number of wait states for the speed your are running.
I checked the Start Up file and I found the stack size as following:
Stack_Size EQU 0x00000400
The STM32L1 has 256K RAM. Note that I'm using Timer interrupts, float, and delay in this code. I don't know how to calculate the recommended stack size. what are the criteria of doing so, and what would be the suitable size for this code. I hope I'm not asking for too much..
You not answering the questions is the problem I have.
The code looks reasonable enough, pretty sure I could paste it into a project and have it work out of the box. I lack sufficient and specific detail in your case to know where/why it stopped or crashed.
Make an effective presentation of what's happening, less narrative, more illustration.
I mentioned where and how, but maybe I misunderstood the question. here's a screenshot that should clear it.
http://imgur.com/a/3qDtE
You were asked to STOP to the debugger, and see where it was then. This is NOT what is portrayed in the image.
You've said where the tracing finished, not where it STOP, or where it was actually stuck. It tries to do the division, and doesn't return, the task in debugging this is to understand where it actually goes and becomes stuck.
You could also go into the disassembly view an STEP INTO rather than STEP OVER.
You screenshot shows that the stackpointer points to 0x20000658. Start the program and stop at main() and look at the SP value. If the difference is close to 0x400 you know the stack might be too small and the problem is a stack overflow. For a test set stacksize to 0x800 in the startup file.
@Westonsupermare Pier
I'm really trying to understand what you're asking me to do here. please consider me as a beginner and give me a clear troubleshooting steps, I would be thankful. I appreciate your support
@Gunnar Bohlen
When I first run the debugger, the first line it execute is the first line after the main(), which is the function SetHSI(). the SP value at that point is 0X20000670. So I increased the Stack to 0x00000800 and the SP value shows 0X20000A60 when executing the Distance line. Similarly, when I increased the stack to 0x000001000, the SP value showed 0X200001260 when executing the Distance line. Not sure what's happening to be honest.
I'll share the complete code in my next post, so you will know what I'm talking about. The code is supposed to calculate the distance by interfacing an ultrasonic sensor, and turn ON a LED if an object closer than 100cm is detected.
#include <stdio.h> #include "stm32l1xx.h" // Keil::Device:Startup //Initialize the timers variables. volatile int timespan = 0; // Total pulse width volatile int lastcounter = 0; // Timer counter value of the last event volatile int newcounter = 0; // Timer counter value of the current event volatile int overflow = 0; // Count the number of overflows void SetHSI(void); void Delay(int); void GPIO_config(void); void TIM2_Trigger(void); void TIM4_Init(void); void TIM4_Echo_Read(void); void LED (void); int main(void){ SetHSI(); GPIO_config(); TIM2_Trigger(); TIM4_Init(); while(1){ TIM4_Echo_Read(); LED(); Delay(100); } } void Delay(int x){ //input milliseconds, delay that number of milliseconds int a,b; for(a=0; a<x; a++){ for(b=0; b<1000; b++){ } } } //set HSI as SystemCoreClock (HSE is not populated on STM32L-Discovery board)// void SetHSI(void) { // Turn on HSI (16MHz) RCC->CR |= RCC_CR_HSION; // Wait until HSI is ready while( (RCC->CR & RCC_CR_HSIRDY) == 0); // Select HSI as system clock RCC->CFGR &= ~RCC_CFGR_SW_HSI; RCC->CFGR |= RCC_CFGR_SW_HSI; while( (RCC->CFGR & RCC_CFGR_SWS)!=RCC_CFGR_SWS_HSI ); // Wait till HSI } // Configure GPIO Port B void GPIO_config(void){ RCC->AHBRSTR |= RCC_AHBRSTR_GPIOBRST; // Reset GPIOB clock RCC->AHBRSTR &= ~RCC_AHBRSTR_GPIOBRST; // Clear Reset RCC->AHBENR |= RCC_AHBENR_GPIOBEN; // Enable GPIOB clock //PB6 Echo Pin GPIOB->MODER &= ~(0x03 << 12); // Clear bit 12 & 13 Alternate function mode GPIOB->MODER |= (0x02 << 12); // set as Alternate function mode GPIOB->OSPEEDR &= ~(0x03<< 12); // 40 MHz speed GPIOB->OSPEEDR |= (0x03<< 12); // 40 MHz speed GPIOB->PUPDR &= ~(0X3<<12); // NO PULL-UP PULL-DOWN GPIOB->OTYPER &= ~(1<<6); // PUSH-PULL GPIOB->AFR[0] &= ~GPIO_AFRL_AFRL6; // Clear pin 6 for alternate function GPIOB->AFR[0] |= 0x2 << (4*6); // set PB pin 6 as AF2 (TIM4_CH1) //PB10 Pluse Generating Pin GPIOB->MODER &= ~(0x03 << (2*10)); // Clear bit 12 & 13 Alternate function mode GPIOB->MODER |= 0x02 << (2*10); // set as Alternate function mode GPIOB->OSPEEDR &= ~(0x03<< (2*10)); // 40 MHz speed GPIOB->OSPEEDR |= 0x03<< (2*10); // 40 MHz speed GPIOB->PUPDR &= ~(1<<10); // NO PULL-UP PULL-DOWN GPIOB->OTYPER &= ~(1<<10); // PUSH-PULL GPIOB->AFR[1] |= 0x1 << (4*2); // set PB pin 10 as AF1 (TIM2_CH3) //PB7 LED ON/OFF GPIOB->MODER |= GPIO_MODER_MODER7_0; // General purpose output mode GPIOB->OSPEEDR |= GPIO_OSPEEDER_OSPEEDR7; // Max High speed 50MHz } // CONFIGURE TIM2 FOR SENDING OUTPUT SIGNAL void TIM2_Trigger(void){ RCC->APB1ENR |= RCC_APB1ENR_TIM2EN; // ENABLE TIM2 CLOCK TIM2->PSC = 159; // SET APPROPRAIT PRESCALER TO SLOW DOWN THE CLOCK TIM2->ARR = 0XFFFF; // SET MAX PULSE WIDTH OF 65536us FOR 16-BIT TIMER TIM2->CCMR2 |= TIM_CCMR2_OC3M_1 | TIM_CCMR2_OC3M_2; // 111: PWM mode 1 TIM2->CCMR2 |= TIM_CCMR2_OC3PE; // CH3 Output Preload Enable TIM2->CR1 |= TIM_CR1_ARPE; // Auto-reload Prelaod Enable TIM2->CCER |= TIM_CCER_CC3E; // Enable Output for CH3 TIM2->EGR |= TIM_EGR_UG; // Force Update TIM2->SR &= ~TIM_SR_UIF; // Clear the Update Flag TIM2->DIER |= TIM_DIER_UIE; // Enable Interrupt on Update TIM2->CR1 &= ~TIM_CR1_DIR; // Set upcounting counter direction TIM2->CCR3 &= ~(TIM_CCR3_CCR3); // Clear CCR3 (Channel 3) TIM2->CCR3 |= 0x1; // Load the register TIM2->CR1 |= TIM_CR1_CEN; // Enable the counter } // CONFIGURE TIM4 FOR RECEIVING INPUT SIGNAL void TIM4_Init(void){ RCC->APB1ENR |= RCC_APB1ENR_TIM4EN; // ENABLE TIM4 CLOCK TIM4->PSC = 15; // SET APPROPRAIT PRESCALER TO SLOW DOWN THE CLOCK TIM4->ARR = 0xFFFF; // SET MAX PULSE WIDTH OF 65536us FOR 16-BIT TIMER TIM4->CCMR1 &= ~TIM_CCMR1_CC1S; // CLEAR CAPTURE/COMPARE REGISTER TIM4->CCMR1 |= 0X1; // SELECT CH1 INPUTE CAPTURE TIM4->CCMR1 &= ~TIM_CCMR1_IC1F; // DISABLE DIGITAL FILTERING TIM4->CCER |= (1<<1 | 1<<3); // SELECT BOTH RISING AND FALLING EDGE DETECTION CC1P & CC1NP TIM4->CCMR1 &= ~(TIM_CCMR1_IC1PSC); // INPUT PRESCALER 0 TO CAPTURE EACH VALID EDGE TIM4->DIER |= TIM_DIER_UIE; // UPDATE INTERRUPT ENABLE TIM4->CCER |= TIM_CCER_CC1E; // ENABLE COUNTER CAPTURE TIM4->DIER |= TIM_DIER_CC1IE; // ENABLE CH1 CAPTURE/COMPARE INTERRUPT TIM4->CR1 |= TIM_CR1_CEN; // Enable the counter NVIC_SetPriority(TIM4_IRQn, 1); // SET PRIORITY TO 1 NVIC_EnableIRQ(TIM4_IRQn); //ENABLE TIM4 INTERRUPT IN NVIC } void TIM4_Echo_Read(void){ if ((TIM4->SR & TIM_SR_UIF) != 0){ // Check the update event flag overflow++; // if UIF = 1, increment overflow counter TIM4->SR &= ~TIM_SR_UIF; // clear UIF } if ((TIM4->SR & TIM_SR_CC1IF) != 0){ // Check capture event flag newcounter = TIM4->CCR1; // read capture value, store as newcounter timespan = (newcounter - lastcounter)+(65536 * overflow); // calculate the total pulse width lastcounter = newcounter; // save the value of newcounter as lastcounter to be used for the next cycle overflow = 0; // clear overflow counter } } void LED (void){ float Distance; // actual distance in cm Distance = (timespan / 58.0); if (Distance <= 100.0){ GPIOB->BSRRL = (1<<7); } else { GPIOB->BSRRH = (1<<7); } }
After it "crashes" press the RED STOP icon and take a screen shot of the code/disassembly window so you can see where it is stuck.
You enable interrupts that you don't service, that's unlikely to end well.
Ok, here's the screenshot:
http://imgur.com/a/xXDSD
Can you be more specific. I'm using Timer interrupt to detect signal rising and falling edges and read the counter values at both ends. At least that's what I think I'm doing.
You can't just randomly enable interrupts without the TIMx_IRQHandler() code to service them. Code you don't show, so assuming it is missing.
Your code is stuck in the Default_Handler code because you don't deal with the interrupt with your own routine.
The TIM will work without the interrupt being enabled.
When you first published your code none of this detail was presented, it is important to make a complete presentation.
I thought I already enabled TIM4 interrupt via the following lines:
TIM4->DIER |= TIM_DIER_UIE; // UPDATE INTERRUPT ENABLE
TIM4->CCER |= TIM_CCER_CC1E; // ENABLE COUNTER CAPTURE
TIM4->DIER |= TIM_DIER_CC1IE; // ENABLE CH1 CAPTURE/COMPARE INTERRUPT
TIM4->CR1 |= TIM_CR1_CEN; // Enable the counter
NVIC_SetPriority(TIM4_IRQn, 1); // SET PRIORITY TO 1
NVIC_EnableIRQ(TIM4_IRQn); //ENABLE TIM4 INTERRUPT IN NVIC
What I'm I missing here..
void TIM4_IRQHandler(void) { // Handle and clear the interrupt you've caused. if (TIM4->SR & TIM_SR_UIF) { TIM4->SR = ~TIM_SR_UIF; // Perhaps read registers or do something related to why you wanted interrupt? } }
I don't believe these concepts are entirely unique to ARM or STM32 parts.