Why is this not working ??

[JHERI]

Hi guys

I have a real strange issue

trying to move two 8bits values in to one 16bit variable,

can someone please tell me why this does not work

It should OR the lsb to the msb

      Sensor_Flow = I2C1_DATA[0] ;

      Sensor_Flow = Sensor_Flow << 8;

      Sensor_Flow = Sensor_Flow || I2C1_DATA[1];

thanks in addvance

[PatrickF]

Hi,

you mixed up || (logical OR) and | (binary OR), please try :

      Sensor_Flow = Sensor_Flow | I2C1_DATA[1];

assuming I2C1_DATA[ ] is defined as bytes array, otherwise need to mask to get only LSByte (i.e. I2C1_DATA[x] & 0xFF) .

Regards,

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[Javier1]

if sensor_flow is uint16_t and I2C_DATA is a uint8_t or char array....

you could also try

memcpy(&Sensor_Flow, &I2C_DATA[0],2);//2=2bytes

[JHERI]

Thanks guys

Just coming back to C after a long break,

Doh back to the drawing board :(

Regards

[JHERI]

Hi guys

don't think mem copy will work as my first byte of data [0] is the msb and byte 2 [1] is lsb

It create the 16bit data variable with the byte order wrong

though I like the simplistic approach

Regards

[Tesla DeLorean · Accepted solution]

Simpler, less prone to be wrong..

Sensor_Flow = ((uint16_t)I2C1_DATA[0] << 8) + (uint16_t)I2C1_DATA[1];