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Topic: Building a large midi controller with multiple arduinos using I2C (Read 1 time) previous topic - next topic

caronte23

Hi everyone, I'd like to build a midi controller with 110 potentiometers. What do you recommend would be the cheapest way to get that many analog inputs?

Grumpy_Mike

CD74HC4067 16 channel multiplexers, you will need 7 of them.

caronte23

CD74HC4067 16 channel multiplexers, you will need 7 of them.
Thanks, and how would I chain 7 together, I'm looking at this image:


Which arduino/s should I get as the main hub?
Also, dumb question, Is it possible to attach a 5 pin midi connector as output instead of usb?
Please excuse me but I'm an extreme noob in this field :/

Grumpy_Mike

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Which arduino/s should I get as the main hub?
The Leonardo and the Micro both can act as a USB MIDI device.
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Is it possible to attach a 5 pin midi connector as output instead of usb?
Lots of projects on the net including mine http://www.thebox.myzen.co.uk/Hardware/MIDI_Shield.html

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and how would I chain 7 together, I'm looking at this image:
Repeat that circuit but instead of sending the input to A0, send it to A1 to A5. I know this is "only" 6, which will give you 96 pots. To get an extra one connect another chip's output to one of the inputs of a multiplexer.

 


MarkT

110 analog channels read by an Uno + multiplexers would take about 12ms to cycle through, ie a maximum
latency of 12ms which is entirely reasonable I think - ie one Arduino Uno or Mini Pro at default analog settings
is plenty.  The pots should be no higher than 50k in value for repeatable performance, 10k/20k/50k are suitable
values.

The default settings on the Uno take about 0.11ms to read one analog sample, you can adjust this for faster response at some compromize on accuracy though.
[ I will NOT respond to personal messages, I WILL delete them, use the forum please ]

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