Slice byte-stream into bit pieces I receive byte data from a RS-232 device with Serial.read();. Now I need to slice this down in bit-pieces:


value1: 15bits
value2: 7bits
value3: 9bits
value4: 12bits
and so on


Data from the stream (switch them around for better understanding):


Byte 1: 00101100 => 00110100 (least significant byte first)
Byte 2: 10011011 => 11011001
Byte 3: 00110011 => 11001100
Byte 4: 11101000 => 00010111
Byte 5: 01001100 => 00110010
Byte 6: 01100111 => 11100110


Now the least significant is first.


value1: 00110100.1101100[1] => 6956
Need to cut of the last bit of the second byte
value2: 1.110011[00] => 103
Add the last bit of the second byte and cut off the last two bits of the third byte
value3: 00.0001011[1] => 416
Add the last two bits of the third byte and cut off the last bit of the fourth byte
value4: 1.00110010.111[00110] => 3737
Add the last bit of the fourth byte and cut off the last 5 bits of the fifth byte


Now the question: How do I realize this from programming side. I'm lost.
Note: This is an answer that OP originally edited into his question.



I gather the data into an array of bytes data[125].

Then I gather the relevant bytes per value and stack them together:

long var = (data[4]&lt;&lt;8) + (data[3]);


I shift them so the relevant bytes start first

var=var&gt;&gt;3;


Afterwards I mask them with the RIGHT mask

var=var &amp; 0xFF;


For the example in my question:

long var = (data[1]&lt;&lt;8) + (data[0]); // I need two bytes  
var=var&gt;&gt;1; // shift them to the right one bit  
var=var &amp; 0x7FFF; // mask it with "0111 1111 1111 1111"