Low power test script for pyboard

lowpower.py

# cycle through standby, stop, wfi, run modes
# uses either rtc wakeup or switch extint
# put pyb.usb_mode(None) in boot.py to save more power
# can also select lower CPU freq using, eg, pyb.freq(64000000)

import pyb, stm
from pyb import Pin

def low_power_test():
    rtc = pyb.RTC()
    led1 = pyb.LED(1)
    led2 = pyb.LED(2)
    led3 = pyb.LED(3)
    led4 = pyb.LED(4)

    if hasattr(Pin.board, 'X1'):
        # pyboard
        pins = [
            (Pin.board.X1,  Pin.PULL_UP),
            (Pin.board.X2,  Pin.PULL_UP),
            (Pin.board.X3,  Pin.PULL_UP),
            (Pin.board.X4,  Pin.PULL_UP),
            (Pin.board.X5,  Pin.PULL_UP),
            (Pin.board.X6,  Pin.PULL_UP),
            (Pin.board.X7,  Pin.PULL_UP),
            (Pin.board.X8,  Pin.PULL_UP),
            (Pin.board.X9,  Pin.PULL_NONE), # I2C SCL
            (Pin.board.X10, Pin.PULL_NONE), # I2C SDA
            (Pin.board.X11, Pin.PULL_UP),
            (Pin.board.X12, Pin.PULL_UP),

            (Pin.board.Y1,  Pin.PULL_UP),
            (Pin.board.Y2,  Pin.PULL_UP),
            (Pin.board.Y3,  Pin.PULL_UP),
            (Pin.board.Y4,  Pin.PULL_UP),
            (Pin.board.Y5,  Pin.PULL_UP),
            (Pin.board.Y6,  Pin.PULL_UP),
            (Pin.board.Y7,  Pin.PULL_UP),
            (Pin.board.Y8,  Pin.PULL_UP),
            (Pin.board.Y9,  Pin.PULL_NONE), # I2C SCL
            (Pin.board.Y10, Pin.PULL_NONE), # I2C SDA
            (Pin.board.Y11, Pin.PULL_UP),
            (Pin.board.Y12, Pin.PULL_UP),

            #(Pin.board.X17, Pin.PULL_NONE), # USR SW already configured
            (Pin.board.X18, Pin.PULL_UP),
            (Pin.board.X19, Pin.PULL_UP),
            (Pin.board.X20, Pin.PULL_UP),
            (Pin.board.X21, Pin.PULL_UP),
            (Pin.board.X22, Pin.PULL_UP),
        ]

    if hasattr(Pin.board, 'MMA_AVDD'):
        pins += [
            (Pin.board.MMA_AVDD,    Pin.PULL_DOWN),
            (Pin.board.MMA_INT,     Pin.PULL_NONE), # BOOT1 pulled low by 100k
        ]

    if hasattr(Pin.board, 'SD_D0'):
        pins += [
            (Pin.board.SD_D0,       Pin.PULL_UP),
            (Pin.board.SD_D1,       Pin.PULL_UP),
            (Pin.board.SD_D2,       Pin.PULL_UP),
            (Pin.board.SD_D3,       Pin.PULL_UP),
            (Pin.board.SD_CMD,      Pin.PULL_UP),
            (Pin.board.SD_CK,       Pin.PULL_UP),
            #(Pin.board.SD_SW,       Pin.PULL_NONE), # already configured
        ]

    if hasattr(Pin.board, 'USB_VBUS'):
        pins += [
            (Pin.board.USB_VBUS,    Pin.PULL_UP),
            (Pin.board.USB_DM,      Pin.PULL_UP),
            (Pin.board.USB_DP,      Pin.PULL_UP),
        ]
        if hasattr(Pin.board, 'USB_ID'):
            pins += [(Pin.board.USB_ID, Pin.PULL_UP)]

    # configure pins as input to reduce current leakage
    for pin, pull in pins:
        pin.init(Pin.IN, pull)

    # function to turn LED pins on/off
    led_pins = [Pin(p) for p in ("LED_RED", "LED_GREEN", "LED_YELLOW", "LED_BLUE")
                        if hasattr(Pin.board, p)]
    def led_off():
        for pin in led_pins:
            pin.init(Pin.IN, Pin.PULL_DOWN)
    def led_on():
        for pin in led_pins:
            pin.init(Pin.OUT_PP, Pin.PULL_NONE)
        if hasattr(Pin.board, "LED_BLUE"):
            Pin.board.LED_BLUE.init(Pin.AF_PP, Pin.PULL_NONE, af=Pin.AF2_TIM3)

    # wakeup callback
    wakeup = False
    def cb(exti):
        nonlocal wakeup
        wakeup = True

    # configure switch to generate interrupt on press
    sw = pyb.Switch()
    sw.callback(lambda:cb(0))

    # function to flash an LED
    def flash(led):
        led.on()
        pyb.delay(100)
        led.off()

    while True:
        # standby (need to exit by pressing RST, or wait 15s)
        if stm.mem32[stm.RTC + stm.RTC_BKP1R] == 0:
            flash(led1)
            stm.mem32[stm.RTC + stm.RTC_BKP1R] = 1
            rtc.wakeup(15000, cb)
            pyb.standby()
        else:
            stm.mem32[stm.RTC + stm.RTC_BKP1R] = 0

        # stop
        flash(led2)
        led_off()
        pyb.stop()
        led_on()

        # idle
        flash(led3)
        wakeup = False
        while not wakeup:
            pyb.wfi()

        # run
        flash(led4)
        wakeup = False
        while not wakeup:
            pass

low_power_test()