Hi there, i wanted to make a game where a sensor would be counting each hit made by the shoe/foot of someone juggling with a soccer ball and the hits would be incremented and displayed on a screen.
I’m new at electronic and circuits and i don’t know how and where to start…
After reading a couple of threads on the forum and tutorials here is what i thought about (not much ahah):
a piezo sensor / accelerometer to count hits ?
something “to record/transmit” the data
something to receive / interpret the data
a screen
Any assistance or direction to start would be much appreciated !
You’d need to make a circuit that can handle the shocks of being kicked. Aside from that, either a piezo or an accelerometer should work.
Interpreting the signals is easy enough with a microcontroller. If you’re not comfortable doing it from the ground up, an arduino would work well.
Another advantage of arduino is that you can hook up a wireless transmitter fairly easily (Xbee or RF transceiver). Then you just need another arduino with a similar system to receive the data and send it to whatever you want (PC, display score on an LCD, whatever).
I think the above is a good outline for a system but I wonder …
Does the ‘hit’ detector in the ball need to distinguish btw contact w/a foot (a kick) and when the ball hits the ground ( a bounce) or something other than a shoe/fo ? A simple piezo detector will treat all the same. I’m not sure how to make a “smart” detector.
Well i was more thinking of a “detector” on the shoe. Each time the shoe/foot would hit the ball it will be “recorded” by the detector. If nothing happens let’s say for 10 sec after the last hit, the game would be over. Do you think it’s something doable ?
Fort a detector on the shoe, an accelerometer wouldn’t work well, since distinguishing between an impact on the ball and a jerky motion would be hard as hell. A piezo might work, but that would require hitting the ball with a fairly specific portion of the shoe and would also react to the shoe hitting the ground. At that point, maybe using a photoresistor is better. When the ball hits it, very little to no light will hit the photoresistor, and you can easily read for that.
yamitenshi:
Fort a detector on the shoe, an accelerometer wouldn’t work well, since distinguishing between an impact on the ball and a jerky motion would be hard as hell.
Agreed.
yamitenshi:
A piezo might work, but that would require hitting the ball with a fairly specific portion of the shoe and would also react to the shoe hitting the ground.
Agreed.
yamitenshi:
At that point, maybe using a photoresistor is better. When the ball hits it, very little to no light will hit the photoresistor, and you can easily read for that.
Hmmmm, how does that not suffer from the same *fairly specific portion of the shoe* problem ?
Up for thought … simple detectors in both the shoes and ball. Hits that happen, and are recorded at the ‘base station’, at the ‘same’ time are a ‘juggle’ ??? Still not sure what a good shoe sensor is. There’s something to be said for both mentioned so far. :think: :think:
A photoresistor would not solve the small target area, but the data would be much easier to interpret (just set a threshold for the value from the resistor and you’re done).
If you look at a sensor on both ends, the communication becomes even more difficult. You can’t hook the shoe and the ball up via wiring. Maybe the PC end could be connected to the shoe via a wire, but that’s not very safe either.
As far as the shoe sensor goes, I think the accelerometer is more trouble than it’s worth. You’d have to take directional values, intensities and patterns into account, and the benefit of being able to hit the ball with the side of your foot is comparatively small.
Perhaps a piezo would be best - it allows a wider target area than the photoresistor, and even though the data would be a bit harder to interpret, it still wouldn’t be dramatically difficult. If it turns out to work, a second piezo in the ball could always be considered, but syncing the time of the signal between two separate controllers could be difficult.
yamitenshi:
If you look at a sensor on both ends, the communication becomes even more difficult. You can’t hook the shoe and the ball up via wiring. Maybe the PC end could be connected to the shoe via a wire, but that’s not very safe either.
My 1'st thought is the ball sensor trips a simple RF beacon to turn on for some msecs. A simple RF detectector is used at the 'base station' to make a binary signal to some MCU. Pretty easy to compare the timing btw 2 digital I/O pins. Add some binary modulation to the beacon if desired.
yamitenshi:
As far as the shoe sensor goes, I think the accelerometer is more trouble than it’s worth. You’d have to take directional values, intensities and patterns into account, and the benefit of being able to hit the ball with the side of your foot is comparatively small.
Perhaps a piezo would be best - it allows a wider target area than the photoresistor, and even though the data would be a bit harder to interpret, it still wouldn’t be dramatically difficult. If it turns out to work, a second piezo in the ball could always be considered, but syncing the time of the signal between two separate controllers could be difficult.
Yeah, a piezo seems to be a front-runner.
An accelerometer in the ball allows code to set the contact threshold. May or may not be worth the $s ?
That would work but I was thinking of something simpler and less $$s, at least to start with. Seems to me that the shoe ‘hit detector’ is the key component and if you get that right you don’t need anything in the ball. So before wrangling w/RF, why not use a wired connection to figure out what’s needed for detectors and then chose the RF link based on what’s needed to support that sensor.
Start w/a piezo feeding into some adjustable threshold (LM339 window comparator?) followed by a 1 shot timer (555). This is wired to your controller & display. You can play w/threshold settings to see if you can eliminate footfall detections but still detect juggles.
Yeah right. Makes sense to start with everything wired. I didn’t know about window comparators and timer. I’ll see how i can handle that and let you know my findings. Thanks for the support !
