Joe Palmer

I think there is a real opportunity here to further develop a project such as this for STEM. Students could be set the fairly striaghtforward task of measuring the time a model car takes to travel a set distance, then introduced to various ways to do this. There are also many "levels" to which the students can accomplish the task allowing for lots of differentiation in marking. Ironically the solution I present here is probably the most basic level, more able students could look to replace the Tx and Rx hardware with faster or more reliable components, improve the code for robustness or investigate wireless options.

Great idea! Please see @JamesA41 comment above regarding laser safety though. My system was used in a classroom environment where I had full control of the room, the students and where the laser was pointing. If you plan to use this sort of system on a public street I would stongly encourage you to use a different (safer) light source and to consult relavent local laws to ensure everything you are doing is above board. Thanks.

Good to know, thanks for the info.

Hi. Thanks very much for this. I will certainly consider this approach on future projects. I think the ultimate aim with this is to make all sensors and Tx sources wireless using nrf24l01 modules, would synchronising the modulated signals at Tx and Rx still be possible in this case? Or would a different approach be a better bet?

Thanks for the suggestion. In this configuration would I still connect the Arduino to each of the LDRs with wires? Or use two Arduinos?

Great suggestion, thanks. If you have a link to a good resource on interrupts please let me know.