3-wire LCD adapter with M74HC595 shift register

5 Volt power supply for ATtiny 85

If you want to detach the Arduino UNO from your project, you must provide power from a different source, a battery pack or DC wall adapter. But be careful! Although DC wall adapters are suitable for this purpose, you should check with a voltmeter if the output voltage is correct. Cheap variable wall adapters tend to be far away from the specified value.

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Although, I’ve set this variable wall DC adapter to 6.0 Volts,
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… its output voltage is at 8.84 Volts!