Go Down

Topic: Input from Photocell or otherwise (Read 1 time) previous topic - next topic

minchster

We have a lumber mill that we need to count the logs coming into the mill.  So the input would be a photocell or some type of switch and then count each log as they come in and at the end of the day be able to have a final count and ability to reset back to zero for the next day.  Brand new to this so looking for any advice.

Far-seeker

That's possible if at some point early on these logs are traveling individually, like down a conveyor belt.  Further details would help...

2Tricky

As it happens I'm working on something similar and have two photocells working in tandem to recognise average greyscale.  In my case, one digitally configured cell tells the Arduino when to read the analogue voltage coming from the other and it works, though I have a bit of noise which I'm trying to troubleshoot in the analogue readings.

minchster

Basically the logs travel up the conveyor belt and before they are cut they need to be counted.  We have 1 shift and at the end of the shift i need the number of logs with a reset to start over for the next day.

Pauly

How fast do the logs move on the conveyor?
Are the logs all the same size?
Is there any space between the logs?
If there is a space, you might be able to a range finder like this one to measure the distance from a set point.  Anything less than the set distance would mean a log.

http://www.pololu.com/catalog/product/1137

minchster

How fast do the logs move on the conveyor?
3 mph
Are the logs all the same size?
No various diameters and lengths

Is there any space between the logs?
Yes almost always at least a foot

If there is a space, you might be able to a range finder like this one to measure the distance from a set point.  Anything less than the set distance would mean a log.
I will take a look into that.  As far as the counter is concerned would that be something i would be able to store as a value and then download / display at the end of shift?
What about the ability to reset that counter for the next days shift?

terryking228

A Infrared Beam pair (Transmitter and receiver) should work well. They can be used over several feet and are relatively immune to other lights (direct sunlight might be a problem)..

Example: http://goo.gl/6P5rQ


DISCLAIMER: Mentioned stuff from my own shop...
Regards, Terry King terry@yourduino.com  - Check great prices, devices and Arduino-related boards at http://YourDuino.com
HOW-TO: http://ArduinoInfo.Info

Pauly

Terry's idea would also work well, although I have never tried it.
If I were making it, I would add a button to reset the counter every day and an LCD screen to display the value.
http://adafruit.com/products/181

Another option might be a data logger, where all your data is stored on an SD card.
You could just make it log the data at the end of every day and pull out the SD card and put it into your computer when you wanted to record the data.
http://adafruit.com/products/243

Go Up