Hi,
This project is for a potato farm. We have planted multiple small test plots that we will need to collect data on after they are harvested. We need to be able to count the number of potatoes in each plot efficiently. We have a washer that eventually places each potato on one of 10 conveyor belts based on size. What we would like to do is have an IR sensor on each belt that counts the number of potatoes that goes through that belt. If possible, we would also like to have a way to have the number counted from each belt sent to a PC (on an excel sheet or a tsv file or something similar). From looking online, it seems like this could possibly be done with the use of an Arduino board, but I've never used one and have extremely limited knowledge of them. If anybody could tell me if this is possible and/or give me an idea of how it would need to be done it would be greatly appreciated.
Ah, sure, can be done. IR LED on one side, photodiode on the other. The moment a potato passes through it goes dark and that's easy to count. There have been a few threads about counting objects in the last few weeks alone.
But: you have to make sure you have only one potato at a time, no overlapping, with space in between. Otherwise they're not counted. Also you have to ensure your sensors remain clean while placed next to dirty potatoes - some dirt on your sensors and it's waiting forever for that huge potato to pass.
A more reliable method may be a video camera above the belt with image recognition software doing the counting. Can handle larger volumes, but definitely harder/more expensive to implement.
wvmarle:
Also you have to ensure your sensors remain clean while placed next to dirty potatoes - some dirt on your sensors and it's waiting forever for that huge potato to pass.
A Sharp IR Distance Sensor could be mounted as low as possible on the side of the conveyor pointing across. The Arduino would sense for a distance less than the conveyor's width count every trigger as a potato. I've never played with these, but I think they should be precise enough. Depending on the conveyer speed it may refresh too slowly.
Anybody have enough experience with these to know if they would work?
There is a LOT of info online about using Excel with Arduino.
The problem with IR sensors in daylight is that the IR content of ambient light overwhelms that of the LED source, making any change of light through an obstruction undetetectable
Hence the normal practice is to modulate the source with a high frequency (typically 38kHz) and have a detector tuned to that.
There are various shields available.
Allan