Found in European documentation from the 1980s, this circuit was originally designed for computer applications of the time. However, the basic idea can be adapted for use with microcontrollers.
April 2017 - The Shields of Seed Grove Modules for Intel Joule can now be obtained from Mouser...
This circuit is indicated to operation with piezoeletric transdicers or other with high impedance...
This circuit is an alternative version of the previous one also found in the July 1995 Electronics Now...