unsigned char ret1 = 0, ret2 = 0;

    s = i2c_start(0x80);       // set device address and write mode
    if ( s ) {
        /* failed to issue start condition, possibly no device found */
        i2c_stop();
    }else {
        /* issuing start condition ok, device accessible */
        i2c_write(0xF5);                       // получить влажность
        i2c_stop();                            // set stop conditon = release bus
        s = i2c_start( 0x81 );       // set device address and read mode
       
   _delay_ms(100);
                                                                       
        i2c_rep_start( 0x81 );       // set device address and read mode
        ret1 = i2c_readAck();                    // read one byte
        ret2 = i2c_readAck();                    // read one byte
        i2c_readNak();                    // read one byte
        i2c_stop();
       
        ret = ret1;
    }
   
    return ret;