Hi,
for my first bigger project with the Arduino (Uno), I would like to make a 16 step Stepsequencer. Since I don't have any experience on this scale yet, I wanted to ask you, if you would do something different. 
I would need 5 multiplexers (74HC 4067) which are controlled by the same digital out pins, one each for frequency (potentiometer, A0), octave (on/off/on switch with a resistor, A1), on/off (switch, digital input), velocity (potentiometer, A2) and an LED to keep track of the current step (no IO needed).
This part is shown in the graphic attached, I would also need one more analog in for a speed pot and one digital switch for on/off as well as the RX / TX pin for a MIDI jack. (I would like to use MIDI jacks for analog synthies etc...)
The programm would iterate through the steps and stay at each step for a specific amount of time. The 4 values have to be read by analogRead or digitalRead every few milliseconds until the next step starts.
Since only one step actually needs power, I think that the 5V from the arduino would do fine and no other power source is needed right?
Is my approach fine or would you change something?
Regarding the graphics: I only draw one poti / switch / ... per multiplexer and I used 4 Channel multiplexer to keep the circuit a bit smaller,..
Cheers
