itla.utils

 1import yaml
 2
 3
 4def setup_registers():
 5    with open("registers.yaml", "r") as yaml_file:
 6        yaml_dict = yaml.safe_load(yaml_file)
 7        registers = {key: yaml_dict[key]["register"] for key in yaml_dict.keys()}
 8        registers_inv = {registers[key]: key for key in registers.keys()}
 9
10        return registers, registers_inv
11
12
13def get_hexstring(register, data, header):
14    """forms the hexstring for the command youre trying to send
15
16    :param register: the register you want to write to
17    :param data: the data to write to the register
18    :param header: the header for the packet
19    :returns: the hexstring for the command
20
21    """
22
23    # Each of these change the parameter to a hex and cut off the 0x part
24    # It may be possible to remove the 0x parts by removing the '#'
25    header_hex = f"{header:#04x}"[2:]
26    register_hex = f"{register:#04x}"[2:]
27    data_hex = f"{data:#06x}"[2:]
28
29    return header_hex + register_hex + data_hex
30
31
32def compute_checksum(hexstring):
33    """Computes the command checksum
34
35    :param register: the register to write to
36    :param data: the data to write the register
37    :param write: whether or not you are writing to the register
38    :returns: the checksum value
39
40    """
41    # get the hexstring for the command without the
42
43    byte_list = bytes.fromhex(hexstring)
44
45    bip8 = byte_list[0] & 15 ^ byte_list[1] ^ byte_list[2] ^ byte_list[3]
46
47    return (bip8 & 240) >> 4 ^ bip8 & 15
48
49
50def form_packet(register, data, write=False):
51    """This computes the checksum and generates the hexstring.
52
53    :param register: the register you want to write to.
54    :param data: the data to write to that register
55    :param write: true or false value for
56    whether you are trying to write to the register
57    :returns: the hexstring for the command you are sending
58
59    """
60    if data is None:
61        data = 0
62
63    if not isinstance(write, bool):
64        raise TypeError("The variable `write` must be True or False")
65
66    hexstring = get_hexstring(register, data, write)
67    checksum = compute_checksum(hexstring)
68    header = checksum * 16 + write
69
70    hexstring = get_hexstring(register, data, header)
71
72    return hexstring