dump from CMS 50F 3.7 v0.3

#!/usr/bin/python
# -*- coding: UTF-8 -*-
# Contec CMS 50F firmware 3.7 dumper
# (C) 2014, François Revol <revol@free.fr>

#cf. http://elinux.org/Serial_port_programming

import serial
import sys
import time


def send_cmd(p, c):
    print "> %s" % c
    c = c.replace(' ', '')
    c = c.decode("hex")
    #print c.encode("hex")
    p.write(c)
    #p.flush()

def recv_data(p, l=None):
    data = ''
    while l is None or len(data) < l:
        time.sleep(0.5)
        if p.inWaiting() < 1:
            print "No more data..."
            # XXX: do something?
            if l is None:
                break
        want = max(p.inWaiting(), 1)
        if l is not None:
            want = min(want, l - len(data))
        # just for nicer hex dump, wrap at 8 bytes
        want = min(want, 8)
        #print len
        d = p.read(want)
        hx = d.encode("hex")
        print "< %s" % " ".join(hx[i:i+2] for i in range(0, len(hx), 2))
        data += d
    print
    return data

if len(sys.argv) < 2:
    print "Usage: %s serialdev" % sys.argv[0]
    exit(1)

#, parity=serial.PARITY_ODD
with serial.Serial(port=sys.argv[1], baudrate=115200) as p:

    send_cmd(p, '7d 81 a7 80 80 80 80 80 80')
    recv_data(p, 2)
    send_cmd(p, '7d 81 a2 80 80 80 80 80 80')
    recv_data(p, 2)
    send_cmd(p, '7d 81 a0 80 80 80 80 80 80')
    recv_data(p, 4)

    send_cmd(p, '7d 81 b0 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 ac 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 b3 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 ad 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 a3 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 ab 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 a4 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 a5 80 80 80 80 80 80')
    d = recv_data(p)
    print "timestamp:"
    packet = d[0:8]
    if packet[0] == '\x07':
        print "%02d%02d-%02d-%02d" % (
            ord(packet[4]) & ~0x80,
            ord(packet[5]) & ~0x80,
            ord(packet[6]) & ~0x80,
            ord(packet[7]) & ~0x80)
    packet = d[8:16]
    if packet[0] == '\x12':
        print "%02d:%02d:%02d.%02d" % (
            ord(packet[4]) & ~0x80,
            ord(packet[5]) & ~0x80,
            ord(packet[6]) & ~0x80,
            ord(packet[7]) & ~0x80)

    send_cmd(p, '7d 81 af 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 a7 80 80 80 80 80 80')
    recv_data(p)

    send_cmd(p, '7d 81 a2 80 80 80 80 80 80')
    recv_data(p)


    send_cmd(p, '7d 81 a6 80 80 80 80 80 80')
    d = recv_data(p)
    print "data:"
    for i in range(0, len(d) / 8):
        packet = d[i*8:i*8+8]
        print "packet %d" % (i)
        if packet[0] != '\x0f':
            print "invalid data packet:"
            print packet.encode("hex")
            continue
        if packet[1] != '\x80':
            print "unknown code for packet: %02x" % ord(packet[1])

        print "%d%% %dbpm" % (ord(packet[2]) & ~0x80, ord(packet[3]) & ~0x80)
        print "%d%% %dbpm" % (ord(packet[4]) & ~0x80, ord(packet[5]) & ~0x80)
        print "%d%% %dbpm" % (ord(packet[6]) & ~0x80, ord(packet[7]) & ~0x80)