dac/ino

This is a pair of boards and corresponding library which provide CV and gate I/O for an Arduino Nano. It is derived from shaduzlabs/synapse, and there are obvious similarities to ArdCore, but there are significant differences with both.

There are two boards, dac/ino and dac/ino lite.

Differences between these and Synapse are:

• Board design with space for Arduino Nano, instead of as Uno style shield
• No on-board jacks — pads for Molex or pin connectors (or direct soldering) instead
• Simplification by eliminating software-controlled range selection
• Number of inputs and outputs is different
• dac/ino lite is battery powered and has 0–5 V output range, also uses Arduino Vcc as voltage reference

Features

dac/ino has

• 4 x control voltage inputs, 0 to 5V
• 2 x control voltage outputs, individually configurable as 0 to 5 V, 0 to 10 V, or -5 to 5 V via jumpers, with 12 bits of resolution
• 4 x gate inputs (with interrupt)
• 2 x gate outputs
• Additional inputs/outputs (direct connections to Arduino): 4 analog, 2 digital
• All above inputs/outputs connect via Molex connectors or solder pads, or via pin headers for daughterboards
• Voltage reference chip
• 1 x eurorack power connector (10 pin)

dac/ino lite has

• 2 x control voltage outputs, 0 to 5 V, with 12 bits of resolution
• 1 x gate output
• Additional inputs/outputs (direct connections to Arduino): 4 analog, 2 digital
• All above inputs/outputs connect via Molex connectors or solder pads
• 6–12 V battery or unipolar power supply

Compatible Arduinos

The PCB layout is for an Arduino Nano (5V).

Dependencies

• DirectIO, for fast digital pin access

Respository

• KiCad format schematics and PCB layouts, and Arduino library and example sketches, may be found at https://github.com/holmesrichards/dac_ino.

• Build notes

• dac/ino schematic (A bit confusing because the repetitive parts of the circuit are handled with KiCad heirarchical pages, so you have lots of pages with only a few components on each.)

• dac/ino PCB layout

• dac/ino BOM

Submodule

This repo uses submodule aoKicad, which provides needed libaries for KiCad. To clone:

git clone git@github.com:holmesrichards/dac_ino.git
git submodule init
git submodule update

Alternatively do

git clone --recurse-submodules git@github.com:holmesrichards/dac_ino.git

Or if you download the repository as a zip file, you must also click on the "aoKicad" link on the GitHub page (it'll have "@ something" after it) and download it as a separate zip file which you can unzip into this repo's aoKicad directory.

If desired, copy the files from aoKicad to wherever you prefer (your KiCad user library directory, for instance, if you have one). Then in KiCad, add symbol library

aoKicad/ao_symbols

and footprint library

aoKicad/ao_tht.