| I am suspicious about this statement for the following reasons: * Some ST patents [0] say they are doing time of flight but have actually came up with slight variation on reflected signal phase shift measurement (see reply by Animats). * Seeing internal API functions like this [1] in APIs they provide for sensors of this family. Of course, this might be something else (e.g. phase shift of internal PLLs/whatever). * The shortest time in which this sensor performs measurement is on the order of few tens of milliseconds, and the high accuracy modes take up to 100ms. True time-of-flight systems (e.g. [2]) should have the answer ready on the order of nanoseconds (for the distances this sensor works at) and I haven't yet seen designs where there is so significant post-processing of the data which could explain this latency. Don't take me wrong, I've worked with VL6180X and VL53L0X (and look forward to work with VL53L1X), and these sensors are the best in this size but I'm just suspicious that they are directly measuring time for the signal to bounce back, but are instead inferring the time based on some other measurements. Actually, this made me think that I probably have photodiodes with wide enough bandwidth laying around so I could check the transmitted signal on oscilloscope. 0: https://patents.google.com/patent/US20160047904A1/en?q=time&... 1: https://linx.wot.lv/selif/s5ylbs51.jpg 2: http://www.ti.com/product/TDC7200 |
