Question about rtnRate

[ishikawa]

Posted on July 10, 2016 at 20:53

Hi 

I would like to get the signal strength very much.

So, please let me ask two questions.

The first one is about a function in vl6180x_api.c.

julien@ST said like following in the Discussion Board named ''How to measure the ToF'':

>No, there is no way to access to the time of flight. Only distance, signal strength, ambiance rate ...

>Signal strength is the amount of the photons coming back from the target.

>You can access to this field ''rtnRate'' in the struct ''VL6180x_RangeData_t'' below.

So, I saw the _GetRateResult function in the vl6180x_api.c.

However, I couldn't understand clearly following part:

>        calcConvTime = m_refConvTime;

>        if (m_rtnConvTime > m_refConvTime) {

>            calcConvTime = m_rtnConvTime;

>        }

>        if (calcConvTime == 0)

>            calcConvTime = 63000;

Please tell me what this function does here.

Next, is the value of the register named RESULT__RANGE_RETURN_RATE the same to that of rtnRate referred to by julien@ST?

If they have the same value, can I get the signal strength with accessing this register directly? Alternatively, can we get the range_return_rate as the signal strength with decoding it in 9.2 format (devides the value by 128)?

>We encourage our customers to use the API, no register access,  available in ST.COM

By the way, how can I access the signal strength without using api?

Because we couldn't transport api functions completely, we would like to create an original function to get the value. Can't we do that?

Best regards

Ishikawa

#vl6180x