電池駆動のデータロガーを作ってみる(4) — machine.lightsleepは動かない

タイトル通りですが、最初の割り込みは上がってきますが、次の割り込みは上がっってこない、おそらくmicroPythonのファームの問題だろうと思うから、やはり実装はpico-sdkでやるけれどもその前に電源電流測定をしてみる

構成は電池はNiH二直に2.2Ωの電流測定用の抵抗経由でラズピコのVSYSに供給

VBUSとVSUSを今は計測してますが、USBは未接続なのでVBUSはほぼ0Vになってます

抵抗(2.2Ω)の両端をテスターで測定すると48mV程度、つまりos.sleep状態の電流はおよそ22mA消費している、十秒に一回はSD書き込みで跳ね上がる

VBUS/VSYSの計測値は以下、USBは未接続だからほぼ0V(VSYSは2.2Ω抵抗をシリーズでその分ドロップ(2.2*22mV)してるはず)

0.01,2.55

0.01,2.55

抵抗両端の電圧測定、つまり電流波形はこんな感じ、1000mAHの電池なら一日半ぐらいは動作可能、ほぼ予測通り

 

<現時点のPythonコード>

RTC関連のクラスがあるので、SD書き込み関連のクラスを追加して見通しをよくした、前回との違いはSDカードの電源供給を書き込み時点だけオンにしている点、時間待ち0.2秒は今少し短くても良さそうだ、システムはアクティブなので信号線からの回り込みでSDカードの電源線の電圧は2V以上はある

#!/usr/bin/python
# -*- coding: utf-8 -*-
from machine import Pin, I2C, ADC
import time
import binascii
import machine, sdcard, uos

#    https://www.waveshare.net/w/upload/0/08/Pico-RTC-DS3231_Sch.pdf
I2C_PORT = 0
I2C_SDA = 20
I2C_SCL = 21
SD_ON = 22

ALARM_PIN = 3
alarm_triggered = False

adc0 = ADC(Pin(26))  # ADC0 pin
adc1 = ADC(Pin(27))  


class ds3231():
#            13:45:00 Mon 24 May 2021
#  the register value is the binary-coded decimal (BCD) format
#               sec min hour week day month year
    NowTime = b'\x00\x45\x13\x02\x24\x05\x21'
    w  = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"];
    address = 0x68
    start_reg = 0x00
    alarm1_reg = 0x07
    control_reg = 0x0e
    status_reg = 0x0f
    
    def __init__(self,i2c_port,i2c_scl,i2c_sda):
        self.bus = I2C(i2c_port,scl=Pin(i2c_scl),sda=Pin(i2c_sda))
        self.alarm_pin = Pin(ALARM_PIN, Pin.IN, Pin.PULL_UP)
        self.alarm_pin.irq(handler=self.alarm_irq_handler, trigger=Pin.IRQ_FALLING)

    def set_time(self,new_time):
        hour = new_time[0] + new_time[1]
        minute = new_time[3] + new_time[4]
        second = new_time[6] + new_time[7]
        week = "0" + str(self.w.index(new_time.split(",",2)[1])+1)
        year = new_time.split(",",2)[2][2] + new_time.split(",",2)[2][3]
        month = new_time.split(",",2)[2][5] + new_time.split(",",2)[2][6]
        day = new_time.split(",",2)[2][8] + new_time.split(",",2)[2][9]
        now_time = binascii.unhexlify((second + " " + minute + " " + hour + " " + week + " " + day + " " + month + " " + year).replace(' ',''))
        self.bus.writeto_mem(int(self.address),int(self.start_reg),now_time)

    def alarm_irq_handler(self, pin):
        global alarm_triggered
        alarm_triggered = True

    def set_alarm_time(self, alarm_time):
        self.alarm_pin = Pin(ALARM_PIN, Pin.IN, Pin.PULL_UP)
        self.alarm_pin.irq(handler=self.alarm_irq_handler, trigger=Pin.IRQ_FALLING)

    # ステータスフラグクリア
        status = rtc.bus.readfrom_mem(rtc.address, rtc.status_reg, 1)
        rtc.bus.writeto_mem(rtc.address, rtc.status_reg, bytes([status[0] & 0xFE]))

    # コントロールレジスタ設定 (INTCN=1, A1IE=1)
        self.bus.writeto_mem(self.address, self.control_reg, b'\x07')

    # アラーム時刻設定
        hour = alarm_time[0] + alarm_time[1]
        minute = alarm_time[3] + alarm_time[4]
        second = alarm_time[6] + alarm_time[7]
        date = alarm_time.split(",", 2)[2][8] + alarm_time.split(",", 2)[2][9]
        now_time = binascii.unhexlify((second + minute + hour + date).replace(' ', ''))
        self.bus.writeto_mem(self.address, self.alarm1_reg, now_time)

    def get_date(self):
        t = self.bus.readfrom_mem(self.address, self.start_reg, 7)
        year = 2000 + bcd2dec(t[6])
        month = bcd2dec(t[5])
        day = bcd2dec(t[4])
        return year, month, day

# time format conversion
def bcd2dec(bcd):
        return ((bcd >> 4) * 10) + (bcd & 0x0F)

"""
def sdmount_getlist():
    sd = sdcard.SDCard(machine.SPI(0), machine.Pin(17))
    os.mount(sd, '/sd')
    files = os.listdir('/sd')   # set to mount point

    for file in files:
        print(file)
"""

class SDLoggerVFS:
    def __init__(self, spi, cs_pin, power_pin):
        self.spi = spi
        self.cs_pin = cs_pin
        self.power_pin = Pin(power_pin, Pin.OUT)
        self.mount_point = '/sd'

    def power_on(self):
        self.power_pin.value(0)
        time.sleep(0.2)

    def power_off(self):
        self.power_pin.value(1)

    def write(self, rtc, value1, value2):
        # SDカード初期化・マウント
        self.power_on()
        sd = sdcard.SDCard(self.spi, Pin(self.cs_pin))
        uos.mount(sd, self.mount_point)

        year, month, day = rtc.get_date()
        filename = f"{self.mount_point}/{year:04d}-{month:02d}-{day:02d}.txt"

        with open(filename, 'a') as f:
            f.write(f"{value1},{value2}\n")

        # アンマウント & 電源オフ
        uos.umount(self.mount_point)
        self.power_off()

def add_time_period_to_rtc_time(rtc):
    # RTCから生の7バイトを取得(BCD形式)
    t = rtc.bus.readfrom_mem(rtc.address, rtc.start_reg, 7)
    
    year = 2000 + bcd2dec(t[6])
    month = bcd2dec(t[5] & 0x1F)
    day = bcd2dec(t[4] & 0x3F)
    hour = bcd2dec(t[2] & 0x3F)
    minute = bcd2dec(t[1] & 0x7F)
    second = bcd2dec(t[0] & 0x7F)
    weekday = t[3] & 0x07  # 1-7
    
    # 月ごとの日数 (うるう年考慮)
    def is_leap(year):
        return (year % 4 == 0 and year % 100 != 0) or (year % 400 == 0)
    def days_in_month(y, m):
        mdays = [31, 29 if is_leap(y) else 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]
        return mdays[m-1]
    
    # 10秒加算
    second += 10
    if second >= 60:
        second = second - 60
        minute += 1
        if minute >= 60:
            minute = 0
            hour += 1
            if hour >= 24:
                hour = 0
                day += 1
                weekday = weekday + 1 if weekday < 7 else 1 if day > days_in_month(year, month):
                    day = 1
                    month += 1
                    if month > 12:
                        month = 1
                        year += 1
    
    # 曜日文字列
    w = ["Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"]
    weekday_str = w[weekday-1]
    
    # alarm_time 文字列形式 'HH:MM:SS,Weekday,YYYY-MM-DD'
    alarm_time_str = "{:02d}:{:02d}:{:02d},{},{:04d}-{:02d}-{:02d}".format(
        hour, minute, second, weekday_str, year, month, day)
    
    return alarm_time_str

# set alarm time period
def set_alarm():
    alarm_time_later = add_time_period_to_rtc_time(rtc)
    print("Alarm time 10 sec later:", alarm_time_later)
    rtc.set_alarm_time(alarm_time_later)
    rtc.alarm_pin = Pin(ALARM_PIN, Pin.IN, Pin.PULL_UP)

def clear_alarm_flag():
    status = rtc.bus.readfrom_mem(rtc.address, rtc.status_reg, 1)
    rtc.bus.writeto_mem(rtc.address, rtc.status_reg, bytes([status[0] & 0xFE]))

if __name__ == '__main__':

    #sdmount_getlist()  # debug pupose only
    
    # make RTC instance
    rtc = ds3231(I2C_PORT,I2C_SCL,I2C_SDA)

    #rtc.set_time('15:38:00,Sunday,2025-09-14') # RTC initialize only once
    set_alarm() # retrigger an alarm
    
    logger = SDLoggerVFS(machine.SPI(0), machine.Pin(17), SD_ON)
    value1 = round((adc0.read_u16() >> 4) * 3.3 * 3 / 4096, 2)  # calculate real voltage and round to 2 degits below decimal point
    value2 = round((adc1.read_u16() >> 4) * 3.3 * 2 / 4096, 2)
    print(value1, value2)
    logger.write(rtc, value1, value2)

    try:
        while True:
            if alarm_triggered:
                alarm_triggered = False
                clear_alarm_flag()
                time.sleep_ms(5)
                
                set_alarm()
                value1 = round((adc0.read_u16() >> 4) * 3.3 * 3 / 4096, 2)  # calculate real voltage and round to 2 degits below decimal point
                value2 = round((adc1.read_u16() >> 4) * 3.3 * 2 / 4096, 2)
                print(value1, value2)
                if (value2 > 1.8):
                    logger.write(rtc, value1, value2)
                # to enter light sleep mode                
                time.sleep(10)
                #machine.lightsleep()
    except KeyboardInterrupt:
        print("terminated")

 

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