check_fix_gps.py

#!/usr/bin/env python3

import sys
import errno
import json
from os import system
from time import sleep
import datetime
import RPi.GPIO as GPIO

GPIO.setmode(GPIO.BCM)
GPIO.setup(26, GPIO.OUT)
GPIO.output(26, GPIO.LOW)


try:
    while True:
        # intended to have gpspipe -w piped to stdin
        line = sys.stdin.readline()
        if not line:
            # parent proc is dead, exit
            break
        # read json gpspipe data
        sentence = json.loads(line)
        # Filter to mode 2 (2d fix) and mode 3 (3d fix)
        if sentence['class'] == 'TPV':
            if sentence['mode'] == 2  or sentence['mode'] == 3:
                current_time = datetime.datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S.%f')
                print(f'[{current_time}] GPS fixed, updating clock')
                GPIO.output(26, GPIO.HIGH)
                system('systemctl start update_clock_gps.service')
                while True:
                    if system('systemctl status update_clock_gps') != 0:
                        current_time = datetime.datetime.utcnow().strftime('%Y-%m-%d %H:%M:%S.%f')
                        print(f'[{current_time}] Clock updated successfully')
                        while True:
                            if system('systemctl status adc_test_startup') != 0:
                                print('ADC test startup not active, starting data collection')
                                system('systemctl start adc_data_collect')
                                break
                            else:
                                sleep(1)
                        break
                    else:
                        sleep(1)
                break
except IOError as e:
    # this was stolen from stackoverflow and probably has a good reason to be here
    if e.errno == errno.EPIPE:
        pass
    else:
        raise e