Signal Frequency of the SPAD sensor VL53L1X

[vishnusf]

Hi,

I am using Getsignalrate function inorder to obtain the photon count of VL53L1X sensor. Could somebody tell me what the frequency of the actual signal is, ignoring the I2C and UART communication speed. Or the signal that we get is completely dependent on the communication speed. I want my signal rate to be 1Mhz.

Thank u 

[John E KVAM · Accepted solution]

GetSignalRate is returned MegaCountsPerSecond. So, if you ran with a timing budget of 30ms and got one number, you should get the same number if you changed to 60ms. 

If you want to compare the signal strengths, you really need MegaCountsPerSecond PerSpad.

The sensor has 256 SPADs (Single Photon Avalanche Diodes) and if the signal is strong, we will turn off a lot of them. And some are occluded, so the max count will not be an integer to account for those partial SPADs.

I'm not sure I get 1Mhz from this. 

But the sensor works best with 20MegaCounts, and above this is will start turning off SPADS. Below this all of them will be activated. 

20Megacounts with 200 SPADs = 0.1MCountsPerSecondPerSpad. 

You control the signal strength by having a more reflective target and a closer target. If you have too much signal, simply move the target farther away, or choose a less reflective (less white) target. 

- john