Hi all...
Has anyone out there had any experience using Capacitance-to-Digital converter chips (CDCs) as the basis of a Theremin, or similar?
If you are familiar with any, perhaps you could recommend one for me to use: i want to try constructing a single-antenna (at this stage...) "theremin" capable of outputting digital proximity data in 16-or-more-bit resolution, with a data rate of at least 1000Hz. I've thought about MIDI, but as far as I'm aware the format only allows for 7 or 8-bit resolution (correct me if I'm wrong...?).
It's the high data rate that I think is the critical factor here, since the digital signal will need further processing before being fed to some kind of oscillator or software synth, thus creating sluggishness in response. From experience, I think that any delay longer than about 1 or 2 100ths of a second between the player's movement and the audible output is too long...
Some chips I've looked at are the Analog Devices AD7747/AD7142/AD7150etc range, and things like Quantum's QT300. The AD chips look like they might not be fast enought (?), but has anyone used the QT300 and know what the data rate from that is?? I've checked the spec sheet (http://www.qprox.com/downloads/datasheets/qt300_102.pdf) but i'm afraid it's a little bit over my head at this stage... it looks promising though.
any thoughts?
Has anyone out there had any experience using Capacitance-to-Digital converter chips (CDCs) as the basis of a Theremin, or similar?
If you are familiar with any, perhaps you could recommend one for me to use: i want to try constructing a single-antenna (at this stage...) "theremin" capable of outputting digital proximity data in 16-or-more-bit resolution, with a data rate of at least 1000Hz. I've thought about MIDI, but as far as I'm aware the format only allows for 7 or 8-bit resolution (correct me if I'm wrong...?).
It's the high data rate that I think is the critical factor here, since the digital signal will need further processing before being fed to some kind of oscillator or software synth, thus creating sluggishness in response. From experience, I think that any delay longer than about 1 or 2 100ths of a second between the player's movement and the audible output is too long...
Some chips I've looked at are the Analog Devices AD7747/AD7142/AD7150etc range, and things like Quantum's QT300. The AD chips look like they might not be fast enought (?), but has anyone used the QT300 and know what the data rate from that is?? I've checked the spec sheet (http://www.qprox.com/downloads/datasheets/qt300_102.pdf) but i'm afraid it's a little bit over my head at this stage... it looks promising though.
any thoughts?