in this video im building a laser gate timer to get the speed of an object. using two lasers and two bluetooth (hc-05) modules with an arduino i am able to calculate the speed of the object with d = vt becase i can measure the distance between the two laser and the time can be found from the arduino. this simple project is fairly accurate however the further the laser distance is the long and more delays can occur thus the laser gate only have an effective range of about 1-40 feet. however the bluetooth seems to have a slight delay when running for too long so a reset must be used to get an accurate time.
