Help making basic laser trip wire program fit my needs..

Dustin

30 mins is possible using the Arduino.

Normal 'int' allows numbers to 32,768 (15 bits plus a sign)

while a long number gives up to 2,147,483,647

I've never had delay work much above 30,000, so I would suggest either doing a two step approach (incrementing a 1 sec counter with a delay(1000), and when it hits 1800 then your 30mins is up).

The other option is to use Millis() ( http://arduino.cc/en/Tutorial/BlinkWithoutDelay ) and make the interval 30 mins or 1800,000 mS.

You simply check if 'its time' and then call the part of the program that does the work.

see http://arduino.cc/en/Tutorial/WhileLoop

It calls the void calibrate() routine

Its possible to have a loop() section that simply just calls the other routines

Your sketch is a little light to comment on, and how and what is on A0. (Ambient light sensor??)

I would use the light sensor to see if there is enough/not enough light, and then run the distance sensor.

Its true you do have trouble trying to run two ultrasonic ping sensors within a short time of each other, but without knowing the book, I can't understand under what scenario they say you can't read two sensors.

You may find a flow chart of your plan will help.

The answer to each is a yes/no which translates to a simple if statement.

The LED blinking can be a simple routine you call, and at the end it returns to the main loop.

Hopefully this powerful laser is not going to pose a danger or nuisance to others.

Mark

Dustin

30 mins is possible using the Arduino.

Normal 'int' allows numbers to 32,768 (15 bits plus a sign)

while a long number gives up to 2,147,483,647

I've never had delay work much above 30,000, so I would suggest either doing a two step approach (incrementing a 1 sec counter with a delay(1000), and when it hits 1800 then your 30mins is up).

The other option is to use Millis() ( http://arduino.cc/en/Tutorial/BlinkWithoutDelay ) and make the interval 30 mins or 1800,000 mS.

You simply check if 'its time' and then call the part of the program that does the work.

see http://arduino.cc/en/Tutorial/WhileLoop

It calls the void calibrate() routine

Its possible to have a loop() section that simply just calls the other routines

Your sketch is a little light to comment on, and how and what is on A0. (Ambient light sensor??)

I would use the light sensor to see if there is enough/not enough light, and then run the distance sensor.

Its true you do have trouble trying to run two ultrasonic ping sensors within a short time of each other, but without knowing the book, I can't understand under what scenario they say you can't read two sensors.

You may find a flow chart of your plan will help.

The answer to each is a yes/no which translates to a simple if statement.

The LED blinking can be a simple routine you call, and at the end it returns to the main loop.

Hopefully this powerful laser is not going to pose a danger or nuisance to others.

Mark

Thanks Mark and I really appreciate the quick response.. So I will look into Milli a little more in depth for my LED and timing issue. As for the light sensor (A0) it is a basic analog sensor that gives a reading of 0-1023 that is constantly running. Without the laser on the photo resistor I get a reading of around 600 and when the laser is on the resistor I get a reading of 1000. The reason I thought you couldnt use the two together is the IR Range Finder is also constantly running and sending a reading. If I can use them together I would be a happy man.

A little info on what I am trying to do.. My fiance is a botany student in college and is trying to create a new strain of a plant that she is still deciding on. I turned a section of a spare room into a small hydroponic setup for her. Everything works great but the problem is the HID light that she uses needs to stay at a certain distance from her plants so they dont get burnt and to get the most out of her light. This becomes a hassle to constantly check distances and raise the light manualy plus it limits time we can spend away from the house (vacations). I looked around on various sites and there is no automatic light lifter. Someone suggested I looked into Arduino about 3 weeks ago and ever since then I have been trying to learn as much as possible. I have already designed the laser system and the winch controlled by a 12vdc 6300 ounce-in torque geared motor that turns very slowly. The laser is mounted 8'' under her light to the size of her garden. The laser bounces off of 7 aluminum pieces and back to the sensor creating a plane so if at anytime the line is broken it triggers the motor until it is read again. So this is where my issues come from. I dont want the system running 24/7 because that is over kill and it will greatly reduce the time the laser is good for. The project box is mounted on top of her hood and this is where the IR Range Finder comes in. I havent bought it yet but I will soon and it will be mounted on top of the box. I need it to measure the distance to the ceiling and stop the motor at a set point from running in case of a malfunction with the laser causing the sensor to think it is tripped. This would be bad because the motor is expensive and I'm not sure if it would rip the light down killing her work. As far as the laser is concerned it is only a 1mw 3vdc .3a laser but it is strong enough to damage an eye. The laser line is visible when on. I also thought about hooking a PIR sensor up to turn off everything if it reads a presence but I will work on that later.

Hopefully this helps in trying to understand what I'm trying to do and become fiance of the year.