Metra

#!/usr/bin/python3
# -*- coding: utf-8 -*-

'''
get measement from multimeter Gossen METRAHit 29S via BD232 serial interface
works with FTDI RS232 USB connection to /dev/ttyUSB0
switch on with: SEt v SEnd <-/ OFF v on <-/
or by holding DATA/CLEAR while switching on the instrument
the meter sends the measurement as 4bit digits with a rate of 9600 bit/s
the BD232 is powered by the RTS and DTR lines
'''

import sys
import time
import argparse

from openmetra import OpenMetra


# Create the parser
ap = argparse.ArgumentParser(description='Get data from Gossen METRAHit 29S')

# Add the arguments

ap.add_argument('-c',
                '--csv',
                action = 'store_true',
                help = 'create csv (together with -t and/or -u)')
ap.add_argument('-d',
                '--device',
                action = 'store',
                dest = 'serial_device',
                default = '/dev/ttyUSB0',
                help = 'device path of serial interface, default is "/dev/ttyUSB0"' )
ap.add_argument('-f',
                '--format_values',
                action = 'store_true',
                default = False,
                help = 'print formatted values (instead of as shown on meter)'),
ap.add_argument('-g',
                '--german',
                action = 'store_true',
                help = 'use comma as decimal separator, semicolon as field separator')
ap.add_argument('-n',
                '--number',
                action = 'store',
                dest = 'number',
                type = int,
                default = 0,
                help = 'get NUMBER measurement values' )
ap.add_argument('-o',
                '--on-off',
                dest = 'on_off',
                action = 'store_true',
                help = 'switch meter on, select send mode and rate and switch off after measurement')
ap.add_argument('-O',
                '--overload',
                dest = 'print_overload',
                action = 'store_true',
                help = 'print OL values as "None" instead of skipping')
ap.add_argument('-r',
                '--rate',
                action = 'store',
                type = int,
                dest = 'rate',
                default = 4,
                help = '''select index for measurement rate: 0:50ms, 1:0.1s, 2:0.2s, 3:0.5s, 4:1s, 5:2s, 6:5s,
                7:10s, 8:20s, 9:30s, 10:1min, 11:2min, 12:5min, 13:10min, default: 4 (1s)''' )
ap.add_argument('-s',
                '--seconds',
                action = 'store',
                dest = 'seconds',
                type = float,
                default = 0,
                help = 'measure for a duration of SECONDS' )
ap.add_argument('-t',
                '--timestamp',
                dest = 'print_timestamp',
                action = 'store_true',
                help = 'print timestamp for each value')
ap.add_argument('-T',
                '--timeout',
                action = 'store',
                type = int,
                default = 10,
                help = 'set timeout for serial port' )
ap.add_argument('-u',
                '--unit',
                dest = 'print_unit',
                action = 'store_true',
                help = 'print unit of measured value')
ap.add_argument('-U',
                '--unit_long',
                dest = 'print_unit_long',
                action = 'store_true',
                help = 'print unit of measured value with explanation, e.g. AC, DC, etc')
ap.add_argument('-v',
                '--version',
                dest = 'version',
                action = 'store_true',
                help = 'show openmetra version')
ap.add_argument('-V',
                action = 'count',
                dest = 'verbose',
                default = 0,
                help = 'increase verbosity')

# parse my argument
options = ap.parse_args()

if options.version:
    print( f'OpenMetra version {OpenMetra.VERSION}')
    sys.exit()

# open connection to a Gossen Metrahit device, without argument it uses '/dev/ttyUSB0'
with OpenMetra( options.serial_device, timeout=options.timeout ) as mh:

    if mh is None:
        print( 'connect error', file=sys.stderr)
        sys.exit()

    mh.set_verbose( options.verbose )

    if options.csv:
        if options.german:
            field_sep = ';'
        else:
            field_sep = ','
    else:
        field_sep = ' '

    measurement = 0
    try:
        if options.on_off:
            mh.wakeup()

            if options.verbose:
                mh.send_command( mh.CMD_FW_STATUS )
                mh.decode_rsp( mh.get_cmd_response(), sys.stderr ) #

            mh.set_rate( options.rate )

            mh.set_mode( mh.MODE_SEND ) # switch to send mode

        start_time = time.time()

        while True: # measurement loop
            if options.number and measurement >= options.number:
                break

            value = mh.get_measurement( options.format_values )
            if value is None and not options.print_overload:
                continue
            unit = mh.get_unit()
            if (options.print_unit or options.print_unit_long) and unit == '': # skip output until unit is available
                continue

            measure_time =  time.time() - start_time
            measurement += 1
            if options.seconds and ( measure_time > options.seconds ): # time over
                break

            if options.print_timestamp: # seconds since start with 3 decimal digits
                timestamp = str( round( measure_time, 3 ) )
                if options.german:
                    timestamp = timestamp.replace( '.', ',' )
                print( timestamp, end = field_sep )
                if options.print_unit or options.print_unit_long:
                    print ( 's', end = field_sep )

            if options.german:
                value = value.replace( '.', ',' )

            print( value, end = '' )

            if options.print_unit_long:
                print ( field_sep + mh.get_unit_long(), end = '' )
            elif options.print_unit:
                print ( field_sep + mh.get_unit(), end = '' )
            if options.verbose > 1 and mh._ctmv is not None and mh.get_rs_string() is not None:
                print ( field_sep + hex(mh._ctmv) + field_sep + mh.get_rs_string()
                       + field_sep + mh.get_special_string(), end = '' )

            if unit == 'W': # special case power -> followed by voltage and current
                for t in ['v', 'c']: # display also voltage and current on the same line
                    sys.stdout.flush()
                    value = mh.get_measurement( options.format_values )
                    if options.german:
                        value = value.replace( '.', ',' )
                    print ( field_sep + value, end = '' )
                    if options.print_unit_long:
                        print ( field_sep + mh.get_unit_long(), end = '' )
                    elif options.print_unit:
                        print ( field_sep + mh.get_unit(), end = '' )
                    elif options.verbose > 1:
                        print ( field_sep + hex(mh._ctmv) + field_sep + mh.get_rs_string()
                               + field_sep + mh.get_special_string(), end = '' )

            print()
            sys.stdout.flush()  # update redirectet output

    except KeyboardInterrupt:
        print()

    if options.on_off:
        mh.wakeup()
        mh.set_mode( mh.MODE_NORMAL ) # switch to normal mode
        mh.set_mode( mh.MODE_OFF ) # switch to normal mode

    sys.stdout.close()  # make 'tee' happy