LEAP#333 Measure Thy Own Voltage
One of the issues with analogue measurements on the Arduino is that typically we assume an accurate 5V reference,
and need to add fudge factors for a calibrated reading.
Well, I borrowed some code and re-read the ADC part of the datasheet again, and there is a neat little trick for
using the 1.1V internal voltage reference to measure (thus calibrate) the supply voltage.
It works, but not without caveats - so although QI, I’m afraid the net result may not be much of an improvement!
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
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LEAP#332 RC Phase Shift Oscillator
Three RC high-pass filter poles add more than 180˚ phase shift on top of
the 180˚ contributed by a class A BJT inverting amplifier with enough gain to sustain positive feeback.
And that’s all you need to make an oscillator.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
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LEAP#331 Getting Blinky with PIC Assembler
Not necessarily everyone’s first choice for embedded development these days, PIC is perhaps now more a right-of-passage! It was Julian Ilett who finally inspired me to try this myself. One thing that held me back was the perception that you have to “downgrade” to Windows in order to get anything going. Challenge accepted, and I quickly learned that the MPLAB X IDE is just perfect and makes PIC development on MacOSX a piece of cake. So let’s get blinky.. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
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LEAP#330 Any-to-any Polarity DC Power Adapter
I recently got a device that has a 2.1mm power connector but in centre-negative configuration.
Unfortunately I don’t have any centre-negative power packs on hand. I could of course just rewire one,
but decided it might be the time to make up a generic any-to-any connector.
In addition to centre-positive and centre-negative output plugs, I included
a 9V battery bypass and polarity rectifier, so that the input supports both centre-positive and centre-negative connections.
And of course an LED power indicator.
As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub
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