I am working on a project to detect the position of an impact using three vibration sensors each one of them linked to a micro-controller(in my case STM32F4) .
Using ADC and UART ,I can plot with a python script the graphic for each of the data received,thus when i do a tap inside the triangle of the three devices(vibration sensor+STM32F4) i can see that there is a delay between the three line chart.
My goal is to detect where the impact has occured and then plot it. I saw that i can do that using triangulation. I would like to do that with a python script and plotting for example the triangle and when an impact occurs inside of it,it shows me its position. As far as i saw,the triangulation is a solution to this but i don't know where to begin or what to do .
How can I do that with triangulation ?
Best Answer
You don't need a timestamp, because the triangulation works on difference of time, so the absolute RTC time has no significance and adds unecessary burden to the MCU. You have to start recodrding with deterministic time (aka cyclic interrupt)in RAM all channels in a circular buffer, when you detect the impact you end the recordings.
Then I would use a cross corelation between each dataset to determine the delay, A vs B, B vs C, A vs C (A,B,C are signals), te cross corelation will give you the rate of similarity between each signal, at its peak value you have the most probable delay between towo signals, then all you have to do is triangulation math.