Peripheral firmware examples description

AN4157

12/24

Doc ID 023629 Rev 1

In this configuration the OPAMP1 amplifies the signal on PA5. The DAC peripheral is

configured to generate a sine wave signal on DAC_OUT2 (PA5) which will be amplified by

the OPAMP1. To monitor the signal:

●

Connect an oscilloscope to DAC_OUT2 (PA5) to display the sine wave signal

generated by the DAC.

●

Connect an oscilloscope to OPAMP1 Out (PA2) to display the amplified (by 2) sine

wave signal.

3.12

Current consumption example

3.12.1

Purpose

This example shows how to configure the STM32F30x or STM32F31x system to measure

different low-power mode current consumption. The low-power modes are:

●

Sleep mode

●

Stop mode with RTC

●

Standby mode with wake up pin (without RTC)

●

Standby mode with RTC

To select the low power modes to be measured, uncomment the corresponding line inside

the stm32f30x_lp_modes.h file.

Note:

STM32F30x or STM32F31x consumption can be measured on the STM32F3DISCOVERY

board by removing jumper JP3, labeled IDD, and connecting an ampermeter.

Note:

When using small packages (48 and 64 pin), the GPIO pins which are not present on these

packages must not be configured in analog mode.

3.12.2

Description

After reset, the program waits for the User button connected to PA0 to be pressed to enter

the selected low power mode.When the RTC is used, the wakeup from low power mode is

automatically generated by the RTC (after 5s).In Sleep mode and Standby mode, press

again the User button to exit the low power mode.

The different low power mode configurations are described below:

Sleep mode

●

System running at PLL (72 MHz)

●

A Flash memory wait state

●

Code running from Internal Flash memory

●

All peripherals disabled

●

Wakeup using EXTI Line (User push-button PA0)