I’ve been getting interested in playing with the attiny, in particular the attiny85 (8 pins!) and the slightly more practical attin84 (14 pins). So I built a very simple programmer that can program either of these and be easy to use while programming.
Maybe music is overstating this a bit, but it’s creating sound (and makes for a second alliteration in the title). Measuring a constant voltage is one thing, but can the discrete DAC put out a waveform? After all, that’s the main idea behind using a digital-to-analog converter (DAC) rather than pulse-width-modulation (PWM).
Arduinos have analog outputs, but they generate a pulse-width modulation (PWM) signal rather than a voltage. There are a number of circuits to create a voltage from a bit representation. One of the simplest and most elegant is the R/2R network, which only needs two resistors per bit.