negative voltages from piezo element
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- earthres
- Posts: 221
- Joined: Fri May 28, 2021 10:48 am
negative voltages from piezo element
Used in "knock" mode with an ADS1115 A/D board, I found that output from a "disturbed" piezo sensor oscillates and produces both negative and positive voltages. Does this mean it's a bad idea to attach this sensor directly to an Arduino analog input pin?
- sj_remington
- Posts: 998
- Joined: Mon Jul 27, 2020 4:51 pm
Re: negative voltages from piezo element
Correct. To be reasonably safe, add a series resistor (e.g. 100K) to limit the current through the input protection and substrate diodes.
Please be positive and constructive with your questions and comments.