Reading values from a digital PH sensor

[markd833]

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Bit shifting two bytes into one signed int

I am reading audio wav file data from SD. Two bytes represent one signed 16 bit Int. (includes negative numbers). My code works for positive numbers but not for negatives. byte a = 16; byte b =0; int ret = (b << 8) + a ; ret becomes 16. this is CORRECT. Horray! byte a = 253; byte b = 255; int ret = (b << 8) + a ; ret becomes 65533. this is NOT correct.... ret should be -3. Arrrrrg. I read about the "Two's complement" method of signed binary representation of negatives but can't seem to…