I’m not a 100% certain as I only glanced at the schematics, but you could probably get two ADSRs out of the Arduino by adding another DAC chip. Dual ADSR?
Well that is nano’s for you. They just don’t tell you these things. Have you by chance installed a new module lately and did this maybe short the 5V supply to the 12V supply and thus fryed the nano’s in your rig?
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This module exclusively uses the +5 volt line, and ground, of course. The Arduino is powered by pin 27 (+5 volts).
Double trouble. Just kidding. These things work well and there’s this cyclic mode that’s really cool. Since I had five boards manufactured, it’s a matter of using them, but your idea is a good one.
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This is totally possible. I took all the modules out today and tested the power lines, everything seems ok. Upon your alert I will check each module individually and see if anyone is affecting the 5 volt line.
I’d suggest that it’s safer to power a Nano with +12V on VIN pin (30), which uses the on-board voltage regulator.
The +5V pin (27) is useful to power other devices on the board such as DAC chips, but using it as power input might be risky because the Nano (or anything connected to its USB) can be damaged if the 5V supply goes over range.
The AREF pin (18) is a +5V reference voltage output, useful for the clockwise end of pot tracks.
I also suggest adding a diode (eg 1N4001) between the +12V rail and the Arduino’s VIN pin.
If the Nano is connected to USB while the +12V supply is not powered, there is a danger that the Arduino’s on-board voltage regulator might be damaged by trying to power all your other modules.
I hope this helps somebody - Nanos are brilliant for evelope generators, LFOs, MIDI, arpeggiators, clock dividers…
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One of my bus boards is shorting +5 to +12. This was recently installed, so the defect didn’t come out of nowhere! Thank you all so much. (I feel kinda dumb)
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Another thing to think about: How much current are these modules drawing? Depending on what they’re doing, a Nano can draw 30 mA on up. And often Eurorack power supplies use an LM78L05 or something similar for +5 V, with a limit of about 100 mA. Three Nanos on one PSU and it’s maxed out.
If a Nano is expected to supply power for stuff off board in addition to itself, its onboard regulator may not be up to it, in which case it does make sense to power it with regulated 5 V on the 5V pin. But between the PSU current limits and the possibility of a short to +12 V, it’s probably best to use +12 V to an LM78L05 on each module.
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Hey guys i have good news i bought new Arduinos and now the envelope generators are working great. Maybe I’ll make a video and post it here.
Regarding the +5V line, here I am using the LM7805, which can reach 1.5A according to the datasheet.
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Did anything ever come of the polyphonic adsr idea?
An Arduino envelope generator with a single set of adsr controls, then say 4 gate ins triggering 4 separate envelopes out would be really useful for my next poly build.
The GitHub on this page, which was apparently working once upon a time, is long gone…
I don’t know of any but for what an electric druid Envgen8c costs you could knock up 6 to 8 ADSRs in the same space as an Arduino and supporting chips.
I was more thinking about cost - if you were going for envgen8cs for 6 voices, envelopes for vca and filters, that’s getting up around £50 on those 12 chips alone.
They are great chips though.
But could you have a single nano set up with, for example, a multiplexer reading two sets of adsr controls, controlling the envelope for the filters and VCAs of multiple channels, reading multiple gate inputs, with multichannel dac outputs?
Well according to some people a quality 8 channel DAC is 25 quid or more. Then would an Arduino be fast enough for two sets of ADSRs
The Arduino ADSR linked above uses SPI to control a DAC. A dual DAC is specified even though only one channel is used. But getting more DAC outputs is harder: A Nano has built in only a single set of SPI pins. I guess you can bit bang SPI on other pins but it’s not trivial.
Filtered PWM might be good enough and there are 6 PWM pins.
A 4 or 6 channel ADSR is probably possible, within some limits of accuracy and speed.
Why is it harder? Only one CS pin is required, channel is addressed through software, 1 channel or 8 it’s all about being able to write to each channel fast enough to produce a smooth ADSR rather than a steppy waveform.
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