1-Wire bulk read

read_ds18b20.py

#!/usr/bin/python3

# bulk-read all attached 1-Wire temp sensors
# see https://docs.kernel.org/w1/slaves/w1_therm.html

bus_base = '/sys/devices/w1_bus_master1/'

def get_temp(addr):
    with open(f'{bus_base}/{addr}/temperature', 'r') as t:
        print (addr, int(t.read().strip())/1000)

def bulk_read():
    with open (bus_base + 'therm_bulk_read', 'r') as bulk:
        trig = bulk.read().strip()
        if trig == '1':  # all temps ready to read
            with open(bus_base + 'w1_master_slaves', 'r') as s:
                slaves = s.read().splitlines()
                for line in slaves:
                    if line.startswith('28-'): # temperature sensor
                        get_temp(line)

with open (bus_base + 'therm_bulk_read', 'w') as bulk:
    bulk.write('trigger\n')
bulk_read()