That circuit that makes that variable frequency seems really clever. So un-complex. Yet so useful. That must be easier to interface this circuit to a micro / arduino than trying to sense the voltage via the AD converter.
I looked into the piezo sensors you suggested but concluded that the FSR strip (300mm) from Interlink is sufficiently sensitive. A piezo sensor that size would be prohibitively costly. The small surface area of the FSR shown in your video would be inadequate because each time I would need to pull the mechanical action out of the grand piano, move the sensor to test the next key, push the action back into the piano and repeat that process 88 times (88 keys on a grand piano!). Thus the strip sensor. But would my 300mm (12in) sensor necessitate changing the capacitors’ and resistor’s parameters? I bought all of the components and have reproduced the arrangement as per your breadboard (using an RCA CD4093BE just like yours), powered by USB 5V, but getting no audio. I suspect I’m not wiring the amp and/or speaker correctly. This is the Adafruit amp I’m using: www.adafruit.com/product/3006 And speaker: www.adafruit.com/product/3923 But I’m only guessing at how to connect them; perhaps I’ve bought the wrong items. This device is such a brilliant idea and I desperately need it to work as my eyesight is failing, but having audio feedback to make this critical adjustment would solve the problem perfectly. This is such an awkward means of communicating with you. May I provide you with my phone# and perhaps you could text me an email address that would facilitate an easier exchange? Or perhaps we could speak at a prearranged time? Seven8Five-3Nine3-Five5Three7. I would not abuse your generosity and would insist on compensating you for your expertise (in the same way that I wouldn’t tune your piano for free!). Thanks, Michael
I would like to ask you two things- 1. I think I can use the 7414 Hex schmidt inverter IC in place of the CD4093 2. Is the second schmidt nand (used as buffer) at all essential?? The output of these ICs are buffered one as per as I know, and will not cause impedance matching problems with the speakers
You will have much better success if you stick with CMOS logic like the 74C14 or 40106 when building RC inverter oscillators. The 7414 is TTL logic and does not have the high input impedance or gain like the CMOS family. The inverter oscillator should be buffered because the output is charging/discharging the timing capacitor and any extra load will alter the frequency output.
I’d like to build the first setup, the one with the oscillator, and hope you can tell me about the 0.1 and the 0.47 uf capacitors: What does their voltage rating need to be? Also, what is the power source and how much voltage?
The operating voltage of the CD4093 is 3 to 15 volts but I was using 5 Volts DC as indicated on the schematic. Any .1uf and .47uf ceramic capacitor will do.
I’m making a device that will detect physical contact between moving parts inside a grand piano, and my highest priority is that the FSR should be as hypersensitive as possible. Your demonstration model appears to achieve this but it’s difficult to know just how hard you’re pressing with your finger. How would you set about tweaking your model to increase its sensitivity? For my needs it’s not measuring the quantity of force to the sensor that’s the issue, but instead it’s the sensor’s capacity to register the slightest touch such as, for example, if a housefly were to land on it. A bit OTT, I admit, but this is what I’m aiming for! Thanks so much for your help.
@@michaelschnelling1192 For that sensitivity you should look into Piezo sensors or even an electret microphone. th-cam.com/video/wEqfHo_guG8/w-d-xo.html
This version with sound is so cool!
Nice one - I've seen the arduino FSR effort before but you have enhanced it - very good
Thank you Mr. Genius.
You are very welcome
That circuit that makes that variable frequency seems really clever. So un-complex. Yet so useful. That must be easier to interface this circuit to a micro / arduino than trying to sense the voltage via the AD converter.
I looked into the piezo sensors you suggested but concluded that the FSR strip (300mm) from Interlink is sufficiently sensitive. A piezo sensor that size would be prohibitively costly. The small surface area of the FSR shown in your video would be inadequate because each time I would need to pull the mechanical action out of the grand piano, move the sensor to test the next key, push the action back into the piano and repeat that process 88 times (88 keys on a grand piano!). Thus the strip sensor.
But would my 300mm (12in) sensor necessitate changing the capacitors’ and resistor’s parameters?
I bought all of the components and have reproduced the arrangement as per your breadboard (using an RCA CD4093BE just like yours), powered by USB 5V, but getting no audio. I suspect I’m not wiring the amp and/or speaker correctly. This is the Adafruit amp I’m using:
www.adafruit.com/product/3006
And speaker:
www.adafruit.com/product/3923
But I’m only guessing at how to connect them; perhaps I’ve bought the wrong items.
This device is such a brilliant idea and I desperately need it to work as my eyesight is failing, but having audio feedback to make this critical adjustment would solve the problem perfectly.
This is such an awkward means of communicating with you. May I provide you with my phone# and perhaps you could text me an email address that would facilitate an easier exchange? Or perhaps we could speak at a prearranged time? Seven8Five-3Nine3-Five5Three7. I would not abuse your generosity and would insist on compensating you for your expertise (in the same way that I wouldn’t tune your piano for free!).
Thanks,
Michael
The amplifier from Adafruit will not work for your application.
Check under the "About" tab on my channels main page for my email address.
I would like to ask you two things-
1. I think I can use the 7414 Hex schmidt inverter IC in place of the CD4093
2. Is the second schmidt nand (used as buffer) at all essential?? The output of these ICs are buffered one as per as I know, and will not cause impedance matching problems with the speakers
You will have much better success if you stick with CMOS logic like the 74C14 or 40106 when building RC inverter oscillators.
The 7414 is TTL logic and does not have the high input impedance or gain like the CMOS family.
The inverter oscillator should be buffered because the output is charging/discharging the timing capacitor and any extra load will alter the frequency output.
Thank you Sir
I looked under ‘About’ and read your channel’s description, but I don’t see an email address.
It should be in the About tab under the description and also if you scroll down you will see a button that you can click to show email address.
I’d like to build the first setup, the one with the oscillator, and hope you can tell me about the 0.1 and the 0.47 uf capacitors: What does their voltage rating need to be?
Also, what is the power source and how much voltage?
The operating voltage of the CD4093 is 3 to 15 volts but I was using 5 Volts DC as indicated on the schematic. Any .1uf and .47uf ceramic capacitor will do.
I’m making a device that will detect physical contact between moving parts inside a grand piano, and my highest priority is that the FSR should be as hypersensitive as possible. Your demonstration model appears to achieve this but it’s difficult to know just how hard you’re pressing with your finger. How would you set about tweaking your model to increase its sensitivity? For my needs it’s not measuring the quantity of force to the sensor that’s the issue, but instead it’s the sensor’s capacity to register the slightest touch such as, for example, if a housefly were to land on it. A bit OTT, I admit, but this is what I’m aiming for!
Thanks so much for your help.
@@michaelschnelling1192 For that sensitivity you should look into Piezo sensors or even an electret microphone. th-cam.com/video/wEqfHo_guG8/w-d-xo.html