my recent reads..

LEAP#242 Minimal Pierce Oscillator

The Pierce oscillator is a derivative of the Colpitts oscillator, and can be implemented using a minimum of components. Typically: a digital inverter, one resistor, two capacitors, and a crystal. The circuit I’m testing here is from KF5OBS, which cuts this down even further by using a BJT in place of the digital inverter and taking advantage of the base-emitter capacitance to eliminate one capacitor As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image


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LEAP#241 General Purpose 358 Amplifier

There’s always room on my bench for another general purpose amplifier. This is another LM358-based Op-Amp audio amplifier circuit, but it turns out to be not so useful. As-is, it suffers from two issues. First R8=1MΩ provides ridiculous gain, so most signals over 50mV or so slam to upper/lower output limits. Second, the push-pull output stage can’t deliver much power. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image


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LEAP#240 Digital Input with Analog Pins

This is a simple demonstration of a tip shared in the Arduino Tips and Tricks email newsletter. On the Arduino Uno, there are 6 analog pins. While we’d normally use AnalogRead to read A/D values and AnalogWrite to write PWM, they can also be used as GPIO digital pins. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub hero_image


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LEAP#236-9 AudioDSP Effects

The AudioDSP project is a custom DSP shield for Arduino, intended for guitar effects processing. So time to try a few effects:

  • Boost is a simple clean boost/volume control
  • Distortion is a simple clipping distortion effect
  • Crunch is a distortion effect using asymmetrical clipping based on Schetzen formula
  • SuperCrunch is a distortion effect using symmetrical clipping based on Schetzen formula hero_image

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