Facing issue in HAL_GetTick() whille reading tick on interrupt
Hello Everyone,
I'm currently working on a project using the STM32L4 micro controller, where I'm developing a multi-level menu system displayed on a Segment LCD. I'm using a magnetic switch connected to a GPIO pin, which is configured to trigger interrupts on both rising and falling edges.
What i am trying to do is,
Main Menu Switching: When the magnetic switch is held for more than 2 seconds, the system should cycle through the main menu options.
Sub menu Navigation: When the magnetic switch is held for 1 second or less, it should allow navigation within the sub menus of the current main menu.
If the switch is held for a duration between 1 to 2 seconds, no action is taken.
Implementation: To achieve this, I use the HAL_GetTick() function to measure the duration for which the magnet is near the switch. Below is a summary of the code:
void HAL_GPIO_EXTI_Callback(uint16_t GPIO_Pin)
{
switch (GPIO_Pin)
{
case BSP_LCD_MAG_SWITCH_Pin:
METER_DEBUG("Magnetic Interrupt\r\n");
uint32_t current_time = HAL_GetTick(); // Get the current time in ms
METER_DEBUG("Current time = %ld\r\n", current_time);
if (!magnet_near_switch)
{
// Rising edge: magnet brought near the switch
magnet_near_switch = true;
start_time = current_time; // Record the start time
METER_DEBUG("start time = %ld\r\n", start_time);
}
else
{
// Falling edge: magnet moved away from the switch
magnet_near_switch = false;
uint32_t hold_duration = 0;
hold_duration = current_time - start_time; // Calculate hold time
METER_DEBUG("hold_duration = %ld\r\n", hold_duration);
if (hold_duration > 2000)
{ // Held for more than 2 seconds
// Switch between main menus
current_menu = (current_menu + 1) % 4; // Cycle through main menus
in_submenu = false; // Exit submenu mode
METER_DEBUG("Update main menu display\r\n");
update_lcd_menu(current_menu);
}
else if (hold_duration <= 1000)
{ // Held for 1 second or less
// Switch between submenus within the current main menu
if (in_submenu)
{
current_submenu = (current_submenu + 1) % 4; // Cycle through submenus
}
else
{
in_submenu = true; // Enter submenu mode if not already in
current_submenu = 0; // Start from the first submenu
}
METER_DEBUG("Update sub menu display\r\n");
update_lcd_submenu(current_menu, current_submenu);
}
}
break;
}
}
Problems I'm Facing:
1)Inconsistent Behavior: Occasionally, the system exits the submenu unexpectedly or doesn't navigate through the main menu as intended.
2)Power Mode Impact: I’m using the sequencer, which places the system in Stop 2 mode during idle states. This seems to affect the accuracy of the HAL_GetTick() function, leading to unreliable timing calculations.
Questions:
1)Timing Accuracy in Low-Power Mode: Is HAL_GetTick() suitable for time measurements in a system that frequently enters Stop 2 mode? If not, what alternatives can I use to get accurate timing, especially for durations like 2 seconds and 1 second?
2)RTC-Based Timing: Would using the RTC peripheral to track the timing be a more reliable approach? If yes, any guidance on implementing RTC-based time tracking in this scenario?
I am not able to get proper time ticks at HAL_GetTick() on an interrupt. please any one suggest me why HAL_GetTick() function not working properly, Did i miss some configuration?
Thanks in advance.
Taksh