CAN Message Utilities for C
============

## Bitfield Manipulation

    uint8_t data[4] = {0x12, 0x34, 0x56, 0x78};
    uint8_t result = getByte(data, sizeof(data), 0);
    uint8_t result = getNibble(data, sizeof(data), 0);
    fail_unless(copyBitsRightAligned(data, 4, 4, 12, result, 4));

## 8 Byte Bitfield Manipulation

TODO setting bit fields is just copying
TODO bring back old uint64_t implementation of getBitField if it's faster /
    simpler

## CAN Signal Encoding

The library supports encoding floating point CAN signals as well as booleans
into a uint64_t payload.

    uint64_t payload = bitfield_encode_float(1, 1, 3, 1, 0)
    // payload == 0x1000000000000000

    payload = bitfield_encode_bool(true, 1, 3);
    // payload == 0x1000000000000000

## CAN Signal Decoding

The library supports parsing floating point CAN signals as well as booleans.

    uint64_t payload = 0xeb00000000000000;
    float float_result = bitfield_parse_float(payload,
            2, // starting bit
            4, // width of the signal's field
            1001.0, // transformation factor for the signal value
            -30000.0); // transformation offset for the signal value
    // float_result == -19990.0

    bool bool_result = bitfield_parse_bool(payload,
            0, // starting bit
            1, // width of the signal's field
            1.0, // transformation factor for the signal value
            0); // transformation offset for the signal value
    // bool_result == true

## Testing

The library includes a test suite that uses the `check` C unit test library.

    $ make test

## Authors

Chris Peplin cpeplin@ford.com

## License

Copyright (c) 2013 Ford Motor Company

Licensed under the BSD license.