Helper library for using Stop & Standby modes with STM32duino on STM32F103Cx microcontrollers.
- Install STM32duino
- Create
STM32sleepdirectory under Arduino IDE's library dir (~Documents/Arduino/librarieson OS X) - Clone all files in this repository to the created directory
- Restart Arduino IDE if it was running
- Include
STM32Sleep.handRTClock.hto your sketch - Code away!
The following code runs the microcontroller normally for 1 second and then sleeps 5 seconds in standby mode. When RTC alarm triggers, the device is reset and the sketch runs again from the beginning.
#include <STM32Sleep.h>
#include <RTClock.h>
RTClock rt(RTCSEL_LSE);
long int alarmDelay = 5;
void setup() {
// We have just started or woken up from sleep! System clock is set to 72MHz HSE.
delay(1000);
sleepAndWakeUp(STANDBY, &rt, alarmDelay);
}
void loop() { } // This is never run
The following sketch disables ADC & GPIO's to save power before entering stop mode. Device is then continuously woken up after 5 seconds by RTC.
#include <STM32Sleep.h>
#include <RTClock.h>
RTClock rt(RTCSEL_LSE);
long int alarmDelay = 5;
void setup() {
// Disable ADC to save power
adc_disable_all();
// Set all GPIO pins to Analog input to save power (this disables pretty
// much all I/O incl. Serial)
setGPIOModeToAllPins(GPIO_INPUT_ANALOG);
sleepAndWakeUp(STOP, &rt, alarmDelay);
}
void loop() {
// We have woken up from sleep! System clock is set to 8MHz HSI.
// Optionally disable peripheral clocks to save power while in Run mode
//disableAllPeripheralClocks();
delay(100); // As the main clock is only 8MHz instead of normal 72MHz this actually takes 900ms
sleepAndWakeUp(STOP, &rt, alarmDelay);
}
#Misc
Thanks for the hard work & inspiration for all the people working on STM32duino!
For more about low power on STM32 devices, see e.g. Low power mode and wake from sleep.