comport.py

# !/usr/bin/python
# coding = utf8
# https://pyserial.readthedocs.io/en/latest/shortintro.html

# Document Reference No.: FT_000161
# Aliasing Vcp Baud Rates Application Note AN_120
# Version 1.2

# MSB of the divisor is 0, so divisor is dividing a 3 MHz clock.
# Each field consists of 4 bytes, ordered as follows: Byte0, Byte1, Byte2, Byte3.
# Bits 13 through 0 denote the integer divisor
# while bits 16, 15 and 14 denote the sub-integer divisor, as follows
# 10,27,00,00 are re-arranged as 00,00,27,10
# This gives 0000 0000 0000 0000 0010 0111 0001 0000
# 16,15,14 = 000 - sub-integer divisor = 0

# FtdiPort.NT.HW.AddReg]
# HKR,,"ConfigData",1,11,00,3F,3F,10,27,00,00,88,13,00,00,C4,09,00,00,E2,04,00,00,
# 71,02,00,00,38,41,00,00,9C,80,00,00,4E,C0,00,00,34,00,00,00,1A,00,00,00,
# 0D,00,00,00,06,40,00,00,03,80,00,00,00,00,00,00,D0,80,00,00

# HKR,,"ConfigData",1,11,00,3F,3F,
# 10,27,00,00, => divisor = 0'h2710 = 0'd10000, rate = 300
# 88,13,00,00, => divisor = 5000,  rate = 600
# C4,09,00,00, => divisor = 2500,  rate = 1,200
# E2,04,00,00, => divisor = 1250,  rate = 2,400
# 71,02,00,00, => divisor = 625,   rate = 4,800
# 38,41,00,00, => divisor = 312.5, rate = 9,600
# 9C,80,00,00, => divisor = 156,   rate = 19,23075
# 4E,C0,00,00, => divisor = 78,    rate = 38,4615
# 34,00,00,00, => divisor = 52,    rate = 57,69225
# 1A,00,00,00, => divisor = 26,    rate = 115,3845
# 0D,00,00,00, => divisor = 13,    rate = 230,76925
# 06,40,00,00, => divisor = 6.5,   rate = 461,53825
# 03,80,00,00, => divisor = 3.25,  rate = 923,077
# 00,00,00,00, => RESERVED
# D0,80,00,00 => divisor = 208.25, rate = 14,40575

# Altera Cyclone III clock is 64 MHz, so let's assume that we could manage to
# achieve highest possible uart rate for FT2232H stated as 12 MBaud

# At page 11/17 see 4.4 Aliasing the FT232H, FT2232H and FT4232H for Baud Rates
# up to 12 MBaud sayng that to alias baud rates between 3 MBaud and 12 MBaud it is
# necessary to use driver version 2.4.20 or later and the most significant bit
# (MSB) of the divisor must be a 1. This will ensure the divisor is dividing a
# 12 MHz clock and not a 3 MHz clock.
# To alias a rate of 12 MBaud to the standard 921600 baud menu option under windows:
# find the best divisor, check that it is sufficiently accurate and then modify the
# appropriate INF file entry.
# 12000000 / 921600 = 13.0208
# The best divisor is 13.25
# 12000000 / 13.25 = 905660 (approx)
# 921600 / 905660 = 101.76%
# This is just within the required 3% tolerance
# Set bits 16:15:14 to 010 for a sub-integer divisor of 0.25, and the lower bits to
# 0'd13 = 0'hD
# MSB must be a 1 as the master clock is 12 MHz
# This gives 1000 0000 0000 0000 1000 0000 0000 1101.
# This gives the 4 bytes as 80 00 80 0D.
# These are re-arranged as 0D,80,00,80

# Replace the 03,80,00,00, entry for the 923077 baud with 0D,80,00,80.
# Incorporating these two changes the FTDIPORT.INF entry becomes
# FtdiPort.NT.HW.AddReg]
# HKR,,"ConfigData",1,11,00,3F,3F,10,27,00,00,88,13,00,00,C4,09,00,00,E2,04,00,00,
# 71,02,00,00,38,41,00,00,9C,80,00,00,4E,C0,00,00,34,00,00,00,1A,00,00,00,
# 0D,00,00,00,06,40,00,00,0D,80,00,80,00,00,00,00,D0,80,00,00

# To alias a rate of 12 MBaud to the standard 19200 baud menu option under windows:
# Note: Divisor = 1 and Divisor = 0 are special cases. A divisor of 0 will give 12 MBaud, and a
# divisor of 1 will give 8MBaud. Sub-integer divisors are not allowed if the main divisor (n) is
# either 0 or 1.
# So replace the 9C,80,00,00, entry for the 19,200 baud with 00,00,00,80.

# Incorporating these two changes the FTDIPORT.INF entry becomes
# FtdiPort.NT.HW.AddReg]
# HKR,,"ConfigData",1,11,00,3F,3F,10,27,00,00,88,13,00,00,C4,09,00,00,E2,04,00,00,
# 71,02,00,00,38,41,00,00,00,00,00,80,4E,C0,00,00,34,00,00,00,1A,00,00,00,
# 0D,00,00,00,06,40,00,00,03,80,00,00,00,00,00,00,D0,80,00,00

# https://superuser.com/questions/954184/disable-automatic-driver-installation-in-windows-10

import os
import serial
import msvcrt

print(" ////////////////////////////////////////////////////////////////////")
print(" File name     : comport.py                                          ")
print(" Author        : Anatoly A. Sharapov                                 ")
print(" Email         : a.a.sharapov@gmail.com                              ")
print(" Phone         : +7 903 231-11-26                                    ")
print(" Company       : PJS MIEA                                            ")
print(" Dep           : 311                                                 ")
print(" Description   : python comport script for reading from com port     ")
print(" Last revision : 30.03.2021                                          ")
print(" ////////////////////////////////////////////////////////////////////")

is_debug = 0
is_log = 1
ser_buf_size = 4096
ser_baudrate = 19200

is_crc8_included = 1
if is_crc8_included:
    if is_debug:
        print("crc8 is included")
    packet_size = 4 # crc8, addr, data_high, data_low
else:
    if is_debug:
        print("crc8 is not included")
    packet_size = 3 # addr, data_high, data_low

ThisPCLocation = os.environ.get('ThisPCLocation')
print("ThisPCLocation = {:s}".format(ThisPCLocation))

if ThisPCLocation== "HOME":
    com_port = 'COM4'
else: # ThisPCLocation== "MIEA":
    com_port = 'COM14'

def _two_8bits_hex_to_16bits_hex(data_high_byte, data_low_byte):
    return data_high_byte << 8 | data_low_byte

def CheckBits(bit1, bit2):
    if bit1 == bit2:
        print("Error occured")

def ReadData(num_bytes):
    bytes_read = ser.read(num_bytes) # read up to num_bytes bytes
                                     # or as much is in the buffer
    num_bytes_read = len(bytes_read)
    return num_bytes_read != num_bytes, num_bytes_read, bytes_read

def ParseData(bytes):
    addr = bytes[0]
    data = _two_8bits_hex_to_16bits_hex(bytes[1], bytes[2])
    return addr, data

def ReadBuf(data_prev):
    bytes_read = ser.read(ser_buf_size) # read up to buf_size bytes
                                        # or as much is in the buffer
    num_bytes_read = len(bytes_read)
    if is_log:
        miea1_data_file.write("ReadBuf --------------> num_bytes_read = {:#d}\n".format(num_bytes_read))
    if is_debug:
        print("ReadBuf -> data_prev = {:#x}, num_bytes_read = {:#d}" .format(data_prev, num_bytes_read))
    i = 0
    addr_list = []
    if data_prev == 0:
        data_list = []
    else:
        data_list = [data_prev]
    while num_bytes_read >= i + packet_size:
        if is_crc8_included:
            addr, data = ParseData([bytes_read[i+1], bytes_read[i+2], bytes_read[i+3]])
        else:
            addr, data = ParseData([bytes_read[i], bytes_read[i+1], bytes_read[i+2]])
        if is_log:
            miea1_data_file.write("ReadBuf -> address = {:#o}, data = {:#x}\n".format(addr, data))
        if is_debug and i < packet_size:
            print("ReadBuf -> data_first = {:#x}" .format(data))
        if is_debug and i > num_bytes_read - packet_size:
            print("ReadBuf -> data_last = {:#x}" .format(data))
        addr_list.append(addr)
        data_list.append(data)
        i += packet_size
    if is_debug:
        print("ReadBuf -> data_last = {:#x}, len(data_list) = {:#d}" .format(data, len(data_list)))
    return num_bytes_read, addr_list, data_list

def CheckDataList(data_list, buf_num):
    data_list_len = len(data_list)
    data_last = 0
    if is_debug:
        print("CheckDataList -> data_list_len = {:#d}".format(data_list_len))
    if data_list_len > 1:
        data_previous = data_list[0]
        if is_debug:
            print("CheckDataList -> data_previous = {:#x}".format(data_previous))
        for i in range(1, data_list_len):
            data_next = data_list[i]
            if is_debug:
                print("CheckDataList -> data_next = {:#x}".format(data_next))
            if not (data_next == data_previous + 1 or data_next == 0 and data_previous == 0xffff):
                print("At buf_num = {:#d}, num = {:#d} failure detected: data_previous = {:#x} data_next = {:#x}" .format(buf_num, i, data_previous, data_next))
                return False, data_last
            data_previous = data_next
        data_last = data_next
        return True, data_last
    return False, data_last

ser = serial.Serial(port = com_port,
                    baudrate = ser_baudrate,
                    bytesize = 8,
                    parity = 'N',
                    stopbits = 1,
                    timeout = None,
                    xonxoff = 0,
                    rtscts = 0)

if not ser.is_open:
    ser.open()

# https://pyserial.readthedocs.io/en/latest/pyserial_api.html
ser.flush()
ser.flush()

print("Port {:s} is opened with baudrate = {:#d} (possibly aliased)".format(ser.name, ser_baudrate))
miea1_data_file = open('miea1_data.txt', 'w')

print("Com port reading and checking in progress and will be stopped")
print("in case any error detected. Print any key to interrupt.")

num = 0
done = False

# 1st read buf
buf_num = 0
num_bytes_read, addr_list, data_list = ReadBuf(0) # 1st buf - no prevous data

progress = {
    0 : '-',
    1 : '\\',
    2 : '|',
    3 : '/'
}

while not done:

    if is_debug:
        print("num = {:#d}" .format(num))
    else:
        try:
            print(progress[buf_num % len(progress)], end = '\b', flush = True)
        except KeyError as e:
            # можно также присвоить значение по умолчанию вместо бросания исключения
            raise ValueError('Undefined unit: {}'.format(e.args[0]))
            done = True

    num += num_bytes_read

    CheckDataListResult, data_last = CheckDataList(data_list, buf_num)
    buf_num += 1

    if not CheckDataListResult:
        done = True

    if msvcrt.kbhit():
        print("\nYou pressed ", msvcrt.getch(),", so now the process will quit")
        done = True

    num_bytes_read, addr_list, data_list = ReadBuf(data_last)

ser.close()
miea1_data_file.close()

if not ser.is_open:
    print ("Port is closed")


# ThisPCLocation = HOME
# Port COM4 is opened with baudrate = 19200 (possibly aliased)
# Com port reading and checking in progress and will be stopped
# in case any error detected. Print any key to interrupt.
# At buf_num = 1850, num = 765 failure detected: data_previous = 0x3373 data_next = 0x8536
# Port is closed