Midigrid: use launchpads & midi grid controllers with Norns

edrapley · 2023-07-11T16:54:46.514Z

I had a little play around and I found part of the issue - with a grid plugged in adding

  print(FallGrid.g.device.cols)

prints: 16, as expected by the script.

changing that to

print(FallGrid.g.device)

prints: table: 0x66bbc8

However with midigrid running using the mod or usual line added to the script we get the error:

/home/we/dust/code/fall/lib/grid.lua:39: attempt to index a boolean value (field 'device')

Because g.device is a bolean true/false and g.device.cols doesn’t return anything but the same error.

Could this be due to line 60 of midigrid.lua setting midigrid.device = true ?

Editing the these lines -

    GRID_WIDTH = FallGrid.g.device.cols + 1
    GRID_HEIGHT = FallGrid.g.device.rows + 1

to

    GRID_WIDTH = 16 + 1
    GRID_HEIGHT = 8 + 1

Actually allows the script to run successfully for a short time, until it freezes with the error:

longer error

lua: /home/we/norns/lua/core/clock.lua:64: /home/we/dust/code/midigrid/lib/devices/generic_device.lua:89: attempt to index a nil value (field '?')

stack traceback:

[C]: in function 'error'

/home/we/norns/lua/core/clock.lua:64: in function 'core/clock.resume'

JaggedNZ · 2023-07-12T01:34:54.934Z

On a very cursory look at Falls grid code, I’d suggest the following:

Try setting GRID_WIDTH = FallGrid.g.device.cols
and changing the function leaf_to_grid_x
return math.floor((value / NORNS_WIDTH) * GRID_WIDTH) +1

Note the switch from ceil to floor (round value down to nearest whole number)
Explanation, I’m assuming value is between 0 & Norns width, if value is 0 then leaf_to_grid_x will return 0, which is off the grid. If value goes negative it might need to be clamped (e.g. if value < 0 then value = 0)

And similar change to GRID_HEIGHT and leaf_to_grid_y will be required.
The grid to leaf functions might also need ammending, but they should cause things to crash.

3-foot-1 · 2023-07-12T03:24:34.429Z

No attempt is being made to persist the “enabled” setting right now, so you are right it returns to “disabled” whenever you restart.

At the moment I do not know of a standard way to persist this setting. It is not a script param (because it is something that you need to set before you enter a script) and I haven’t seen any guidance for how a mod should persist settings outside of a script. If I can figure out how to make the setting persistent I will.

Note that I did consider simply removing that setting and having midigrid active whenever the mod itself is enabled. I haven’t gone for that yet for a couple of reasons:

changing the setting would require retarting norns each time
there are more settings that I want to add to the mod menu, so the problem of persisting settings within the menu as to be solved one way or another

As to the name: it has been suggested that we merge this mod into Midigrid itself, so something like “Midigrid Mod” is probably the right way to go!

JaggedNZ · 2023-07-14T09:26:03.985Z

Update thanks to @3-foot-1 just a few bug fixes.
Falls now confirmed working (still has a bug, but it does cause MidiGrid failure)
This should potentially fix issues seen with other scripts.

Incase anyone missed it dreamsequence is also working now.

edrapley · 2023-07-14T11:53:46.050Z

Thanks for your suggestion!

Changing the leaf_to_grid & grid_to_leaf function as suggested has helped and now the script can run with another edit at lines 39 & 40 in Fall:

I think the issue is that midigrid breaks the usual operation of FallGrid.g.device.cols because it breaks FallGrid.g.device.

Instead what works is FallGrid.g.cols so line 39 & 40 now read -

    GRID_WIDTH = FallGrid.g.cols
    GRID_HEIGHT = FallGrid.g.rows

3-foot-1 · 2023-07-14T17:33:55.799Z

With the most recent update, midigrid’s device attribute should now conform to most scripts expectations.

shieldfan · 2023-07-17T09:49:39.657Z

Thanks to the community for this Midigrid addon.

I have taken bits from this thread to make it work with my two Launchpads Mini MKIII on Arcology. After some trial and errors, here’s what works for me.
After installing Midigrid, goto : CODE>ARCOLOGIES>LIB>_grid.lua to edit it.
Type this at the begining, (right after “_grid = {}”) :

_grid = {}
local grid = include(“midigrid/lib/midigrid”)
grid:init(‘128’)
g = grid.connect()

Previously tried : local grid = include(“midigrid/lib/mg_128”), but I was getting errors. This made it work. Hope this helps.

jsilence · 2023-07-27T15:17:08.183Z

The link to the official documentation is still broken. Is there any alternative way to read the docs?

edrapley · 2023-07-27T19:05:49.631Z

Here it is:

github.com

p3r7/test-export-wiki-js/blob/master/authors/jaggednz/midigrid.md

---
title: midigrid
description: midigrid documentation
published: true
date: 2022-03-15T22:12:32.404Z
tags: utilities, lib
editor: markdown
dateCreated: 2021-03-22T07:58:30.003Z
---

# midigrid


Migigrid is a grid emulator/shim for using midi grid controllers with Norns

Special thanks to @beepboop @tim52 @ground_state @thopa and any other early contributors I may have missed for getting this all started.

## install

from maiden type

This file has been truncated. show original

jsilence · 2023-07-29T08:08:49.444Z

Thanks a lot!

I am trying to understand the protocol, but it is not 100% clear to me.

The (midi)grid controller is sending Midi note on when pad is pressed and Midi note off when a pad is released, correct?

The mapping between Midi note and grid position is configured in the device setting files.

The script is sending Midi note on messages with certain velocity to light up a pad with different brightness. Also configured in the device setting file. Correct?

The script is sending Midi off messages to switch a pad off. Correct?

JaggedNZ · 2023-07-29T11:36:53.293Z

Yup, on a surface level you are correct. Midigrid creates a virtual grid to help facilitate the mapping from grid to midi devices and the allows things like quad switching and multiple launchpads. It also helps buffer when scripts try to update the grid quickly.

Edit: oh right the deluge, where is wooks development at? I do happen to live in the same city as Synthstrom HQ …

jsilence · 2023-07-29T11:48:33.480Z

The Deluge does not act like a USB controller since its USB is a host. So we‘ll have to go pure Midi here with a USB-to-5pin Midiadapter on the Norns side. I will use a Blokas Midihub for this.
Midigrid will not be able to auto detect the correct device type. Hoping I can hard wire the deluge device type somewhere. Any pointer appreciated.
Forked and branched Midigrid already and installed on my Norns. Working on the device file is the next step. (Also need to get two 5pin Midi cables. How could I not take some on vacation? Stupid me!)

Status of Development on Deluge: coder hero wook churned out Midi feedback mode that lights up pad leds on incoming Midi notes and a fixed keyboard view sans scrolling that spans eight octaves over the 128 pads.

Anything else you think the Deluge needs?

anon60283851 · 2023-07-29T11:57:37.374Z

jsilence:

The Deluge does not act like a USB controller since its USB is a host. So we‘ll have to go pure Midi here with a USB-to-5pin Midiadapter on the Norns side. I will use a Blokas Midihub for this.

Deluge acts as a class compliant USB MIDI device / slave as well so no need for extra adapters. Just hook it up to computer or Norns via the same port you would use for charging or USB host - simply use a standard USB cable instead of the “unisex” one you would use for the host functionality.

I don’t think I ever tried mine with Norns but the manual said it draws up to the normal ~500mA from the host’s USB port max., so at least in theory it ought to work fine even bus powered, provided you have a good power supply (the official RPi one or similar) for the Norns Shield.

jsilence · 2023-07-29T12:08:31.686Z

WHAT!? I had no idea! This is awesome! Thanks!
Will test ASAP. Away from my synths right now.

Edit: had the brief chance to test, and yes, this works just as you said.

Edit: having partial success. But grid seems to be 8x8 instead of 8x16. Wondering why.
Also leds are not lighting up. Probably related to the quad logic that I have not grokked completely.

local deluge = include('midigrid/lib/devices/generic_device')

deluge.grid_notes= {
  {112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127},
  {96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111},
  {80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95},
  {64,65,66,67,68,69,70,71,72,73,74,75,76,77,78,79},
  {48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63},
  {32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47},
  {16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31},
  { 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10,11,12,13,14,15}
}

deluge.height=8
deluge.width=16
deluge.rotate_second_device=false

deluge.brightness_map = {0,4,8,16,24,32,40,48,56,64,72,80,88,96,104,125}

return deluge

JaggedNZ · 2023-07-29T23:19:07.592Z

Have a look at the linnstrument device implementation for an idea of how to tackle quads.

If you can’t figure that out see if you can get the left 64 buttons working and if you have success with that I might be able to jump in and help as it would likely improve midigrid support for all 128key devices …

jsilence · 2023-07-30T12:34:42.865Z

The left 8x8 of the Deluge grid are working, but without feedback.
I am working through the codebase, trying to understand how things are connected.
Looking at cheat codes 2 and other scripts like spirals to see how they invoke the midigrid.

One thing I don‘t understand the reasoning behind: midigrid has to be initialized from the script with the layout. I would rather expect the device file to define the layout and have that initialized from within. But as said, I am working my way through the logic.

3-foot-1 · 2023-07-30T20:20:15.923Z

The script decides the layout becausse the script stands in for the user’s intent: did you want to plug in a grid 64, or did you want to plug in a grid 128? Because some of the devices (like launchpad) allow paging, you can emulate a grid 128 on just a 8x8 device, so just knowing what devices are out there doesn’t tell you the user’s intent.

Edit: if you don’t want to deal with hacking scripts to enable midigrid, give the polygrid mod a try, See the post above (Midigrid: use launchpads & midi grid controllers with Norns - #426 by 3-foot-1)

As an added bonus, as of around 5 minutes ago polygrid persists its settings and allows you to choose the grid size.

Edit: that said, I have hopes that polygrid will soon be superceded by native support in in midigrid itself.

jsilence · 2023-07-30T23:48:34.008Z

Hm ok, so if the script requests a 8x8 layout, but the user plugs in a 128 device, then only the 8x8 of the first quad are used?

Anyway, digging through Norns lua code and learning a lot. Have not coded in lua before. Wishing code was more commented. Having a lot of “but why” and “where does this come from” moments. But prodding thu and having fun.

In core/config.lua (line 20): local tu = require ‘tabutil’
In core/norns.lua (line 13): local tab = require ‘tabutil’
but why? (and also why not local tabutil = require ‘tabutil’)

polygrid sounds great. Will use for sure. Once I figured out how to code the device definition for the Deluge as midigrid.

3-foot-1 · 2023-07-31T00:03:16.464Z

I’m actually not sure what midigrid will do with an 8x8 layout and a 128 device. I’ll argue that if it does not use only the 8x8 of the device it is a bug.

But midigrid is greedy in its consumption of devices. In my experience it will pull in all of the devices it can find, whether it needs them or not. If you have two launchpads and choose a 64 layout, it will put the same 64 display on both devices, rather than leave one alone.

JaggedNZ · 2023-08-01T10:11:37.196Z

To be clear the 64 grid vs 128 grid vs 256 grid initialisation just sets the size and dimensions of the “virtual” grid created by midigrid. Midigrid then attempts to map this the available devices.

Some assumptions have been made, such as devices are 8x8 and you want to use all available compatible devices. And I think it’s a good time to review a few of these …