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Diffstat (limited to 'README.mkd')
| -rw-r--r-- | README.mkd | 28 |
1 files changed, 24 insertions, 4 deletions
@@ -3,26 +3,46 @@ 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 result = bitfield_parse_float(payload, + 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 - // result == -19990.0 + // float_result == -19990.0 - bool result = bitfield_parse_bool(payload, + 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 - // result == true + // bool_result == true ## Testing |