This is a very cool video - love it - but is an Arduino really practical to use for a music keyboard multiplexer? Do they have 61 spare pins sitting there to receive on/off signals? Oh wait, you mention matrix wiring at the end, but I think most of those still need...is it 16 pins?
You are correct. The bare minimum for an organ like this would be 16 pins. There are various arduino models with different numbers of pins. The Arduino Mega2560 or Due, for example, would have 54 available pins. Similarly, the teensy 3.5, 4.1, or teensy++ 2.0 would work. If you get a board with plenty of pins, then you can have a more logical matrix arrangement (grouping by octaves, for example). That doesn't change the performance but it makes the programming simpler for people, like me, who tend to get confused in their for loops. ;)
@@grantsreviews4299 Hi Grant, I am attempting to add these optical switches to three manuals. I have a control unit that has one pin per key. I don't have the electronics knowledge that will enable me to wire up 61 keys x 3 using the optical switches you illustrated. You mentioned that the sensor side doesn't need any resistors. I presume that means that they can be wired the same as my (useless) mechanical switches - common power bus and individual wires to the controller? The beam side for all switches will be always on and the key will break the beam to . Can these also be connected to power in parallel? Will there need to be any resistors involved? Thanks so much for your advice. Jim
@@jimwebster991 It sounds like you on on the right track. It's two separate systems. One system just turns on all the LEDs like a set of christmas lights--always on and powered by a wall wart or whatever. Normally you wire them in serial but you could do parallel if you want. You will almost certainly need a resistor on that side to make sure you don't burn out the LEDs. Now, separately, you wire up the switch side, with no resistors. The switches will be connected only to your control unit and not to your wall wart or the other circuit. If you have enough pins to do every key, it's easy. Otherwise you wire it up in a matrix format, which sounds complicated but is quite doable--it doesn't really require electronics knowledge. Good luck!
@@grantsreviews4299 Thanks so much for your super prompt reply! One last question - if I have 61 of the led's wired in parallel, and the circuit is 9 to 12v DC and 1.4A. Will I need resistor(s) for this parallel circuit? And, if so, how many? I'm guessing on at the beginning to get the current down to what the optical led's can handle?
Great video. Probably they only place on the internet where you get a good summary of all of the various switch types. Extremely useful!
This is a very cool video - love it - but is an Arduino really practical to use for a music keyboard multiplexer? Do they have 61 spare pins sitting there to receive on/off signals? Oh wait, you mention matrix wiring at the end, but I think most of those still need...is it 16 pins?
You are correct. The bare minimum for an organ like this would be 16 pins. There are various arduino models with different numbers of pins. The Arduino Mega2560 or Due, for example, would have 54 available pins. Similarly, the teensy 3.5, 4.1, or teensy++ 2.0 would work. If you get a board with plenty of pins, then you can have a more logical matrix arrangement (grouping by octaves, for example). That doesn't change the performance but it makes the programming simpler for people, like me, who tend to get confused in their for loops. ;)
@@grantsreviews4299 Hi Grant, I am attempting to add these optical switches to three manuals. I have a control unit that has one pin per key. I don't have the electronics knowledge that will enable me to wire up 61 keys x 3 using the optical switches you illustrated. You mentioned that the sensor side doesn't need any resistors. I presume that means that they can be wired the same as my (useless) mechanical switches - common power bus and individual wires to the controller? The beam side for all switches will be always on and the key will break the beam to . Can these also be connected to power in parallel? Will there need to be any resistors involved? Thanks so much for your advice. Jim
@@jimwebster991 It sounds like you on on the right track. It's two separate systems. One system just turns on all the LEDs like a set of christmas lights--always on and powered by a wall wart or whatever. Normally you wire them in serial but you could do parallel if you want. You will almost certainly need a resistor on that side to make sure you don't burn out the LEDs. Now, separately, you wire up the switch side, with no resistors. The switches will be connected only to your control unit and not to your wall wart or the other circuit. If you have enough pins to do every key, it's easy. Otherwise you wire it up in a matrix format, which sounds complicated but is quite doable--it doesn't really require electronics knowledge. Good luck!
@@grantsreviews4299 Thanks so much for your super prompt reply! One last question - if I have 61 of the led's wired in parallel, and the circuit is 9 to 12v DC and 1.4A. Will I need resistor(s) for this parallel circuit? And, if so, how many? I'm guessing on at the beginning to get the current down to what the optical led's can handle?
@@jimwebster991 Yeah you will need to look up the forward resistances and do the same math I did in the video. Good luck!