I am building a custom sensor array composed of 10,000 infrared phototransistor.
This would require 1250 shift registers.
Given that would induce considerable latency to poll and would definitely exceed the RAM on a standard Arduino, my plan was to spread the processing across multiple Arduinos at 1000 inputs each (10 Arduinos total).
That doesn't bother me but 1250 shift registers / 10 still equals 125 per board which takes up a lot of real estate and extra soldering.
I am wondering if anyone knows of a shift register or package able to multiplex more inputs more efficiently, or a possible alternative solution?
At 50 cents per part that would be over $500, but your prices must be quite a bit less than that including the PCB cost.
Suggest you use serial to parallel to enable VCC to one row of 8 transistors at a time, then read the result of that row.
Something like this, no time now (eye injection day) to add the photo transistors to the circuit.
LarryD:
At 50 cents per part that would be over $500, but your prices must be quite a bit less than that including the PCB cost.
It's a conservative figure, by no means absolutely fixed just an ideal maximum.
I already have a stockpile of Arduinos, and I own a CNC router so plan on fabbing my own boards.
As for the rest of the discrete components it's amazing how cheaply you can get stuff from China.
Suggest you use serial to parallel to enable VCC to one row of 8 transistors at a time, then read the result of that row.
Something like this, no time now (eye injection day) to add the photo transistors to the circuit.
An amazingly simple solution, didn't think of using a shift out register together, that reduces part count quite a bit.
I hope you didn't spend too much time with that diagram it's more than I ever expected.
What would be the advantage of the Bobuino? If it's just the extra RAM I intend on using a Raspberry PI as my master, not only does it have plenty of RAM but also built in display support so I can easily output the data from the array.
