how make time depend

Question

Hi there, my frist post, on e14 community (just to you know, im a nurse in a nursing home, have some experience in arduino, (copy/past coding, and i have an quadcopter based in the Ardupilot)

Now my problem, i have an pacient with Alzheimer disease, that fall asleep in the toilet, some times more than an hour, i want to use an HC-SR04 range finder to make a simple task: (a detail the toilet is used by other that use regularly the toilet)

Scanning distance to target (person sit on toilet)

IF is less to 50cm AND for more than 10min

Activate LED

Activate a Servo ( to pull the emergency bell)

Loop

Now im trying to learn the code, and i understand the code for range findings, and millis (to time), but i didint get the way to make the statemant IF => 50 && 6000sec

Cant see a way to create the code

I hope you help me

jw0752 · Answer

Hi Jorge, Sorry I can't answer your specific question but I will throw out an idea anyway. The bathroom in the nursing home where my mother is a resident has a sensor for the light switch. When someone walks in the light turns on and if there isn't any motion in the room the light turns off after a couple minutes. Perhaps a light sensor like this could be used to sense when your patient is still in the room but has fallen asleep. For example if your distance sensor says the the patient is on the toilet and the light in the room goes out, which can be detected with a simple photo transistor, then the LED alarm will be triggered. If there is a pull string in the room there is a switch attached to it. I wouldn't bother with a servo but would instead just put a relay with contacts in parallel to the call switch that is activated by the same logic that turns on the LED to trigger the call system. This may simplify the coding or give you some other ideas to try out. Good luck. John

how make time depend

Top Replies