quantum sensors for DIN

[Guest robm]

Hi there,

I'm interested in using proximity sensor ICs from the quantum research group (http://www.qprox.com) as input for a midibox project. specifically i'm looking at the QT320 sensors. although i've built a midibox64 with the mbhp i still don't know too much about electronics. can anyone tell me if these sensors could be used as digital inputs for the DIN module? here are some excerpts from the datasheet regarding output:

Output are open-drain and require a (10K) pullup resistor

They may be set to either active high or active low

Output processing options can be set during the cloning process

In DC mode the out pins respond to detections with a steady-state active logic level, this state will endure for the length of time that a detection exists or until a MOD timeout occurs. The polarity of OUT can be set via the cloning process. Each channel can be set for this feature independently. Either active-low or active-high can be selected.

Toggle mode gives out pins a touch-on/touch-off flip-flop action so that its state changes with each detection. Outputs can sink up to 2mA of non-inductive current. Max. low output voltage in DC Mode: 0,4V

the full datasheet is here: http://www.qprox.com/downloads/datasheets/qt320_103.pdf

[TK.]

Hi Robm,

you don't need to buy those sensor ICs, MIOS provides a software based solution - up to 128 capacitive touch sensors can be connected :-)

A schematic diagram can be found here:

http://www.ucapps.de/mbhp/mbhp_din_touchsensors.pdf

This article describes, how it works:

http://www.midibox.org/cgi-bin/yabb/YaBB.cgi?board=concepts;action=display;num=1062462975;start=1#1

Best Regards, Thorsten.

FAQMARKER

[Guest robm]

hi thorsten,

thanks for the prompt and illuminating reply  :) i was looking at the quantum ics because they claim to work for electrodes behind non-conducting materials like relatively thick perspex or glass, and this would be necessary for my application. would this also be the case for the capacitive sensors you describe?

[TK.]

Hi Robm,

ok, this possibly wouldn't work with this low-cost solution due to the missing amplifier. And an amplifier would also require a schmitt trigger circuit to improve the stability. All this is integrated in the QT320 device (-> keyword hysteresis).

You only have the connect the DINs with the appr. OUTx pins of the QT320. The programming of the sensor characteristics could also be done from a MIOS application, but it requires some programming skills...

Best Regards, Thorsten.