CMWX1ZZABZ-091 -StandBy/Stop mode and Power consumption.

[GWisn.1]

Dear Members. I'm a beginner and trying to learn and understand how to work with stm32l0 and SH1276. The first task which i set to myself is to reach the absolut minimum power consumption.

Watched some tutorials and tried to reach minimum which i measured practically at ca 3uA when using the lrwan end node example code.

Despite my changes i reach only 3,3 mA (configured to stop mode with RTC and interrupt as a wakup).

What can i do to decrease the power consumption to the expected level during stop?

Thank You.

 
 
This is in main():
HAL_SuspendTick();
HAL_PWR_EnterSTOPMode(PWR_LOWPOWERREGULATOR_ON, PWR_STOPENTRY_WFI);
	 	  	
SystemClock_Config();
HAL_ResumeTick();
 
This is the system clock which CubeMx made based on the L072-Lrwan pcb.
void SystemClock_Config(void)
{
  RCC_OscInitTypeDef RCC_OscInitStruct = {0};
  RCC_ClkInitTypeDef RCC_ClkInitStruct = {0};
  RCC_PeriphCLKInitTypeDef PeriphClkInit = {0};
 
  /** Configure the main internal regulator output voltage
  */
  __HAL_PWR_VOLTAGESCALING_CONFIG(PWR_REGULATOR_VOLTAGE_SCALE1);
  /** Initializes the RCC Oscillators according to the specified parameters
  * in the RCC_OscInitTypeDef structure.
  */
  RCC_OscInitStruct.OscillatorType = RCC_OSCILLATORTYPE_HSI|RCC_OSCILLATORTYPE_LSI;
  RCC_OscInitStruct.HSIState = RCC_HSI_ON;
  RCC_OscInitStruct.HSICalibrationValue = RCC_HSICALIBRATION_DEFAULT;
  RCC_OscInitStruct.LSIState = RCC_LSI_ON;
  RCC_OscInitStruct.PLL.PLLState = RCC_PLL_ON;
  RCC_OscInitStruct.PLL.PLLSource = RCC_PLLSOURCE_HSI;
  RCC_OscInitStruct.PLL.PLLMUL = RCC_PLLMUL_6;
  RCC_OscInitStruct.PLL.PLLDIV = RCC_PLLDIV_3;
  if (HAL_RCC_OscConfig(&RCC_OscInitStruct) != HAL_OK)
  {
    Error_Handler();
  }
  /** Initializes the CPU, AHB and APB buses clocks
  */
  RCC_ClkInitStruct.ClockType = RCC_CLOCKTYPE_HCLK|RCC_CLOCKTYPE_SYSCLK
                              |RCC_CLOCKTYPE_PCLK1|RCC_CLOCKTYPE_PCLK2;
  RCC_ClkInitStruct.SYSCLKSource = RCC_SYSCLKSOURCE_PLLCLK;
  RCC_ClkInitStruct.AHBCLKDivider = RCC_SYSCLK_DIV1;
  RCC_ClkInitStruct.APB1CLKDivider = RCC_HCLK_DIV1;
  RCC_ClkInitStruct.APB2CLKDivider = RCC_HCLK_DIV1;
 
  if (HAL_RCC_ClockConfig(&RCC_ClkInitStruct, FLASH_LATENCY_1) != HAL_OK)
  {
    Error_Handler();
  }
  PeriphClkInit.PeriphClockSelection = RCC_PERIPHCLK_I2C1|RCC_PERIPHCLK_RTC;
  PeriphClkInit.I2c1ClockSelection = RCC_I2C1CLKSOURCE_PCLK1;
  PeriphClkInit.RTCClockSelection = RCC_RTCCLKSOURCE_LSI;
  if (HAL_RCCEx_PeriphCLKConfig(&PeriphClkInit) != HAL_OK)
  {
    Error_Handler();
  }
}

[Tesla DeLorean]

The DISCO board?

Probably check is the TCXO is off, and what parts (LEDs, etc) are hung off it externally.

Lowest power would be in STANDBY, basically restarting at some later time via RTC+LSE

[GWisn.1]

Thank You @clive1.

The board is my custom made board but i keept the compatibility with B-L072 Lrwan Discovery. The Pin PA12 is connected to TCXO just as the Discovery board.

However i don't see any differance by changinge it's state output to hi or low. The current consumption is alsmost the same. Or is ther other way of switching off the TCXO than just changing to low/hi?

When You say hung off it externally do You mean i should put them in their GPIO-analogue mode?

Thank You