HAL_GetTick() running 1.024x fast (v1.3.0) #61
Description
Describe the set-up
Board: MB1389D (Nucleo-WL55JC1)
Describe the bug
HAL_GetTick() and by extension TIMER_IF_GetTimerValue() run at exactly 1.024x speed (2.4% inaccurate) compared SysTimeGet()
How to reproduce the bug
- locate the LoRaWAN_End_Node project (or likely any other)
- add the following lines below to lora_app.c at the start of SendTxData():
APP_LOG(TS_ON, VLEVEL_ALWAYS, "HAL_GetTick()=%u\r\n",HAL_GetTick());
SysTime_t curtime = SysTimeGet();
APP_LOG(TS_ON, VLEVEL_ALWAYS, "SysTimeGet()=%u\r\n",curtime.Seconds*1000+curtime.SubSeconds);
- Build and program
- Open a serial terminal emulator like HTERM
- compute ( <HAL_GetTick() t1> - <HAL_GetTick() tn> ) / ( <SysTimeGet() t1> - <SysTimeGet() tn> ) and you will get 1.024
- Verify SysTimeGet() is accurate by using Hterms timediff feature after selecting all the serial output between <SysTimeGet() t1> and <SysTimeGet() tn> and comparing to (<SysTimeGet() t1> - <SysTimeGet() tn>) (off by -62ppm in my case)
fix
In uint32_t HAL_GetTick(void) in sys_app.c replace TIMER_IF_GetTimerValue() with SysTimeGet().
Note: my testing SysTimeGet() takes 4-5us to compute, not a big deal, but maybe there is a more efficient way to do this
uint32_t HAL_GetTick(void)
{
uint32_t ret = 0;
/* TIMER_IF can be based on other counter the SysTick e.g. RTC */
/* USER CODE BEGIN HAL_GetTick_1 */
/* USER CODE END HAL_GetTick_1 */
// if (SYS_TimerInitialisedFlag == 0)
// {
// /* TIMER_IF_GetTimerValue should be used only once UTIL_TIMER_Init() is initialized */
// /* If HAL_Delay or a TIMEOUT countdown is necessary during initialization phase */
// /* please use temporarily another timebase source (SysTick or TIMx), which implies also */
// /* to rework the above function HAL_InitTick() and to call HAL_IncTick() on the timebase IRQ */
// /* Note: when TIMER_IF is based on RTC, stm32wlxx_hal_rtc.c calls this function before TimeServer is functional */
// /* RTC TIMEOUT will not expire, i.e. if RTC has an hw problem it will keep looping in the RTC_Init function */
// /* USER CODE BEGIN HAL_GetTick_EarlyCall */
//
// /* USER CODE END HAL_GetTick_EarlyCall */
// }
// else
// {
// ret = TIMER_IF_GetTimerValue();
// }
/* USER CODE BEGIN HAL_GetTick_2 */
SysTime_t curtime = SysTimeGet(); //TIMER_IF_GetTimerValue() is 1.024x fast
ret=curtime.Seconds*1000+curtime.SubSeconds;
/* USER CODE END HAL_GetTick_2 */
return ret;
}