i've done many tries. I just want to see if the red LED inside the sensor is alive. At least by sending a command to activate it.

Code:
This is as from the pseudo code the first step. I really do not know if that is the right way to send Device ID + write mode
Then send the FIFO_WR_PTR (i still dont know what are the bits needs to be configured)
REPEAT START

addr = $04   ; FIFO WRITE POINTER REG ADDR IS 0X04
i2cwrite  SDA,scl,contwr
i2cwrite  SDA,scl,contwr,addr
i2cwrite  SDA,scl,contwr
i2cwrite  SDA,scl,contwr,addr

Apart from pseudo code in the datasheet, Next i tried to send mode for the heart rate mode only

addr = $09   ' mode configuration 
i2cwrite  SDA,scl,contwr,addr,[modled],error ' ModLED = $02 as per data sheet heart rate mode only

In the end i tried to send the led pulse amplitute. 

addr = $0C   ' led pulse amplitute
i2cwrite  SDA,scl,contwr,addr,[led1_pa],error' LED1_PA = $3F  , 12.6 mA
no luck......keep walking.