In this Assignment we had to build a Machine that can move along multiple axis. The whole project had to be done as group.
We decided to make a ball tossing game where the target moves when it is hit, The FAB FLY PONG
My task was to build the target itself and the sensor that recognizes if the target ist hit.
How the whole project works can be found here
at our group page.
When I was planning the sensor I tested many sensor that where lying around that did not work.
The first one was an accelerometer so when the target is hit it swings from the impact of the ball and that
is picked up by the sensor. But that did not work because moving the target abruptly will trigger the sensor too.
The next one was a light sensor that did not work either because a change in the roomlighting would require a recalibration of the sensor.
Then I tested a self made touch sensor consisting of two pieces of aluminum foil and a spacer, so when its hit
the two pieces of aluminum touch closing the circuit and sensing the hit. But the pingpong-balls where too
lightweight to trigger this reliably.
Finally I found laser emitter In my sensor box. When this thing hits the a photoresistor it cancels out the
roomlight because it is strong enough to cancel it out. So no recalibration is needed. On the left you can see
the complete sensor-circuit. Consisting of a photoresistor, the emitter and a 10k resistor.
I designed the ring with fusion 360 I tested a few different target sizes to make sure it is not too easy or too
difficult to throw a ball trough the ring. I lasercut it out of MDF (5mm) (power 100 speed 70).
I soldered everything directly to the cables so no extra board was needed then I glued everything in target ring.
before gluing cut away the part of the fall that will be occupied by the cables and sensor like seen on the picture
When you glue it make sure that the laser is turned on so you can see if it hits the sensor. (My laser beam
was exactly the size of the sensor so it had to be placed carefully).
The code for this sensor ist pretty simple it just plug the Data-Pin to an analog Pin (here A2 of an ATmega)
and you are good to go. It simply pulls the analog value and checks if its under a certain threshold.
(You may need to find another threshold for your setup).
Favourite beverage of the Assignment
Just black tea to stay awake and maybe to hunt some Wyvern
