LED/Sound to Cornhole Board

Hi folks,
I was looking to install a PIR motion sensor on the underside of my cornhole board that would sense when a bean bag enters the cornhole which would then be connected to LED RGBW strip lights and a DFplayer sound module which would also play a siren sound. So in addition I would need a speaker and a battery operated power supply. Since I am a newbie I am looking for the easiest/cost effective way to do this. Not sure which components I need: arduino, breadboard, LED, sound module, PIR sensor, power supply, etc.

Start by making a list of all of the I/O needed - every input and every output. Leave a little room for expansion/feature creep. Include also serial driven displays and communication links and such.

I'm not sure PIR is the best sensor choice. PIR stands for Passive Infrared Sensor. That means it senses movement of warm objects. That works best with warm blooded creatures like people. The bean bag is likely to be about the same temperature as the rest of the environment so it will be invisible to the PIR sensor.

I did a similar project to this last year where I needed to count items thrown through a slot in a box in rapid succession

Active modulated IR sensors work well for this sort of thing but they have a narrow active range. In my case the hole the thrown object would pass through was significantly larger than the object so I needed a wide sensor range, which would have meant around 7 of those fairly pricey sensors. I found the ultrasonic sensors had a much wider range. In the end it turned out I needed two of them and I could never get the thing to detect 100# of the time due to the object moving fast and not getting false triggers due to the sensors interfering with each other.

Finally I gave up on the ultrasonic and started looking for other options. I came up with the idea of having a plate of sheet metal below the slot, which was angled so that the thrown object would always strike the plate, but then fall off it to the bottom of the box. I tried a load cell but it was too slow to detect that momentary strike. I also looked at vibration sensors (basically a enclosed spring that closes a contact when impacted) and that seemed promising but by then I had already found another solution: a piezo disk mounted to the plate. It worked great! You can find an example of using one here:

PERT,

Wouldn't the piezo vibration sensor go off when bean bags hit the top of the board?

It’s possible. You’d have to rig up a quick prototype and test it out. If you mount the strike plate in a way that isolates it from vibration (they have rubber vibration isolation mounts for this) then you should get a significantly higher signal from an impact on the strike plate than you would from a hit on the board. So you just need to experimentally determine and set the correct threshold in your code. In my application I had to do this to make it sensitive enough to sense a small lightweight object striking the plate but not trigger from ambient vibrations. I was able to do so in a way that reliably detected every strikes but didn’t get false positives.

It may be that for your application the IR sensor is a better choice. I believe the hole is not much larger than the beanbag? If so you may be able to just use a single sensor. Still much more expensive than a piezo disc for a good modulated IR sensor but still not so bad. I think the IR sensors I found on eBay or Aliexpress were around $5. They do have unmodulated IR modules for <$1 including shipping but I had trouble with those getting triggered by sunlight or even my computer monitor so I gave up on them.

I think I would go the load cell route. Make the plate larger than the hole and build walls around it so the bags would stay on the plate after entering. If the weight goes up by x amount, lights and sirens are activated. The bags would (or should) be roughly the same weight. Say they're 4 ounces roughly. If the weight increase > 3 ounces, set off the lights and alarm. Set the total weight to whatever it actually is reading. If it goes up by 3+ again,.... You get the point.

Just an idea.

thanks guys...i'll start experimenting soon and keep u posted