Read a piezo sensor & value of resistor

Forum 2005-2010 (read only) Hardware Interfacing
1

Hello.
I have a plan to make midi-out-kit using 16 analog piezo inputs with MC14067B.

(datasheet: http://www.onsemi.com/pub/Collateral/MC14067B-D.PDF)
(using mc14067b: http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1138666403/5#5)
(midiout: Spooky Arduino Projects #4 – Musical Arduino – todbot blog)

Because I'm a beginner, I don't know why I have to use 1M resistor to my piezo.
I only have 10kohm and 220ohm resistors. (If I must use 1Mohm resistor, I have buy it.)

  1. What is the difference if I use 10k resistor on behalf of 1M resistor?
  2. Can I use 10k resistor on behalf of 1M resistor?
  3. If I connect piezos to MC14067B, should I connect 1M resistors to each analog input of MC14067B?

Thank you.

2

Because I'm a beginner, I don't know why I have to use 1M resistor to my piezo.

There was a discussion about this recently. Search for username todbot.

I only have 10kohm and 220ohm resistors. (If I must use 1Mohm resistor, I have buy it.)

Buy some. They won't break the bank.

  1. What is the difference if I use 10k resistor on behalf of 1M resistor?

It won't work.

  1. Can I use 10k resistor on behalf of 1M resistor?

As far as I know, no you can't.

  1. If I connect piezos to MC14067B, should I connect 1M resistors to each analog input of MC14067B?

Not sure. Probably yes.