Hello, I'm trying to build a system for getting impulses from bouncing balls on a medium board, for driving sounds or a step sequencer.
The cheapest solution was about using a piezo-electric disc, that transform the mecanic impulsion into electrical energy. So I use the analog input of the Arduino interface for receiving this energy amount, and then I just have to choose a threshold level of the released energy, for triggering into PureData.
But the problem I'm encountering is that the electrical circuit made by the piezo probe and the arduino, with no other additionnal component has a too high capacitance, so the energy level is lowering too slowly after each mecanical impulsion, then my system doesn't trig anymore until the circuit capacitance goes below the threshold level set in PureData.
There certainly is an electronical trick for discharging the energy just after each impulse, maybe someone that read this message has sufficient skills in electronics to help?
Thanks,
pk.
if I understand you correctly, you use the piezo sensors as microphones. I think you need to use an amplifier to get good data. otherwise, the signal will be too weak. building your own amp on a breadboard is tricky, you need some extra electronic parts. (there should be a tutorial on physical computing sites). if your problem is really only the capacitance, then pull the charge off by inserting a pull-down resistor or a voltage divider. marius.
Patrice Colet wrote:
Hello, I'm trying to build a system for getting impulses from bouncing balls on a medium board, for driving sounds or a step sequencer.
The cheapest solution was about using a piezo-electric disc, that transform the mecanic impulsion into electrical energy. So I use the analog input of the Arduino interface for receiving this energy amount, and then I just have to choose a threshold level of the released energy, for triggering into PureData.
But the problem I'm encountering is that the electrical circuit made by the piezo probe and the arduino, with no other additionnal component has a too high capacitance, so the energy level is lowering too slowly after each mecanical impulsion, then my system doesn't trig anymore until the circuit capacitance goes below the threshold level set in PureData.
There certainly is an electronical trick for discharging the energy just after each impulse, maybe someone that read this message has sufficient skills in electronics to help?
Thanks,
pk.
PD-ot mailing list PD-ot@iem.at http://lists.puredata.info/listinfo/pd-ot
Hi Patrice,
Why not just use a microswitch if your just measuring the moment of contact for all the balls? Should be easy enough to find one with a spring strong enough for your application.
.b.
Patrice Colet wrote:
Hello, I'm trying to build a system for getting impulses from bouncing balls on a medium board, for driving sounds or a step sequencer.
The cheapest solution was about using a piezo-electric disc, that transform the mecanic impulsion into electrical energy. So I use the analog input of the Arduino interface for receiving this energy amount, and then I just have to choose a threshold level of the released energy, for triggering into PureData.
But the problem I'm encountering is that the electrical circuit made by the piezo probe and the arduino, with no other additionnal component has a too high capacitance, so the energy level is lowering too slowly after each mecanical impulsion, then my system doesn't trig anymore until the circuit capacitance goes below the threshold level set in PureData.
There certainly is an electronical trick for discharging the energy just after each impulse, maybe someone that read this message has sufficient skills in electronics to help?
Thanks,
pk.
PD-ot mailing list PD-ot@iem.at http://lists.puredata.info/listinfo/pd-ot
On 08/01/2008, at 15.54, Patrice Colet wrote:
But the problem I'm encountering is that the electrical circuit made by the piezo probe and the arduino, with no other additionnal component has a too high capacitance, so the energy level is lowering too slowly after each mecanical impulsion, then my system doesn't trig anymore until the circuit capacitance goes below the threshold level set in PureData.
Maybe the threshold is better set in the in the uC/Arduino code. Tod E. Kurt's done something similar building a "drum kit" with the Arduino board and piezos, cf. [1].
[1] <http://todbot.com/blog/2006/10/29/spooky-arduino-projects-4-and- musical-arduino/>