Step through all possible modulations/configurations for ISO/IEC 15693 with CR95HF-VMD5T from STMicroelectronics discovery kit M24LR-DISCOVERY used command: Inventory

ISO15693_with_CR95HF.py

#!/usr/local/bin/python

# Author: Thorsten Bosbach 09/2018
# Step through all possible modulations/configurations for ISO/IEC 15693 with CR95HF-VMD5T from STMicroelectronics discovery kit M24LR-DISCOVERY
# Used command: Inventory
# Never forget, to read after every write, else strange looking results ;-) ! 

import hid
import time
import sys
import numpy
 
# Looks like there is some timing involved to get repeatable reliable result
sleepy = 0.02
# To check reliability, how often should each command get executed in a row - I would expect each time of this same result
repeat = 1


# Read from CR95HF and print as hex, if no error
def print_read(h):
    count = 0
    for n in range(0, 1):
        time.sleep(0.3)
        d = h.read(64)
        new_str = ""
        for i in range(0, d[2]+3):
            new_str += "%02x " % d[i]
        # 0x80: no error; last byte 0x00: CRC ok
        if d[1] == 0x80 and d[d[2]+2] == 0x00:
        #if d[1] == 0x80:
            print new_str
            count += 1
        else:
            print "**"
        return count

# connect to reader
h = hid.device()
h.open(0x0483, 0xd0d0)

# use command to verify connection without tag available
h.write([0x02, 0xbc])
print_read(h)

# Possible modes as reader, from datasheet cr95hf.pdf DocID018669 Rev 12 page 21 Table 12
# bits
# 5:4: 00: 26 Kbps (H) 01: 52 Kbps 10: 6 Kbps (L) 11: RFU
#   3: 0: Respect 312-us delay 1: Wait for SOF (1)
#   2: 0: 100% modulation (100) 1: 10% modulation (10)
#   1: 0: Single subcarrier (S) 1: Dual subcarrier (D)
#   0: Append CRC if set to 1. (1)

# As a table, list of combinations, most important to me is speed and subcarrier
#       8      4          2        1
# Kbps SOF Modulation Subcarrier Append_CRC :  Hex
#  10   0      0          0        1       :  0x21
#   l   0      0          1        1       :  0x23
#  01   0      0          0        1       :  0x11
#   x   0      0          1        1       :  0x13
#  00   0      0          0        1       :  0x01
#   h   0      0          1        1       :  0x03
# Always let the CRC calculated by reader

# Inner array with these base values
reader = [0x03, 0x01, 0x13, 0x11, 0x23, 0x21]

# Outer array to switch: Respect 312-us delay + 100% modulation, Wait for SOF + 100% modulation, Respect 312-us delay + 10% modulation, Wait for SOF + 10% modulation
addition = [0x00, 0x08, 0x04, 0x0c]

# ISO command request flag combinations for speed and subcarrier ISO-15693-3.pdf 7.3.1 Request flags
# bits 1-4:
#	   Sub-carrier	Data_rate
# 0x04:	single	    low
# 0x06:	single	    high
# 0x05:	dual	    low
# 0x07:	dual	    high
# bits 5-8: 0x20			1 slot
token = [0x24, 0x26, 0x25, 0x27]

# array big enough to count successfull recievements
#                         token, reader, addition
result_array =  numpy.zeros((0x28,0x24,0x0e))

# Outer loop
for a in addition:
    print "+++" + "%02x" % a + "+++++++++++++++++++++++++++++"
    # Inner loop
    for r in reader:
        # Set reader configuration
        h.write([0x01, 0x02, 0x02, 0x01, r+a])
        print_read(h)
        print "---" + "%02x" % r + '----------------------------'

        for t in token:
            for i in range(0, repeat):
                time.sleep(sleepy)
                # inventory command
                h.write([0x01, 0x04, 0x03, t, 0x01, 0x00])
                time.sleep(sleepy)
                sys.stdout.write("0x%02x " % t)
                result_array[t][r][a] += print_read(h)
        # reader field off
        h.write([0x01, 0x02, 0x02, 0x00, 0x00])
        print_read(h)

# Switch reader field off
h.write([0x01, 0x02, 0x02, 0x00, 0x00])
print_read(h)
h.close()

# print summary - see upcoming blog entry for theory behind this :-) and how it came to this....
sys.stdout.write('      ')
for a in addition:
    sys.stdout.write("%x" % a)
print '-'
sys.stdout.write('      ')
for r in reader:
    sys.stdout.write("0x%02x|" % r)
print '-'
for t in token:
    sys.stdout.write("0x%02x: " % t)
    for r in reader:
        for a in addition:
            if result_array[t][r][a] == 0:
                sys.stdout.write(' ')
            else:
                sys.stdout.write(str(int(result_array[t][r][a])))
        sys.stdout.write('|')
    print '-'