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.

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