Roudi is a ROUter for miDI messages, created for the Blokas Midiboy.
I use my digital piano as a master keyboard. Sadly, like many digital pianos, it has very limited MIDI capabilities.
So, I wrote Roudi to overcome these issues without having to go through a computer.
Highlights:
- Easily switch the output channel. Name the channels.
- Setup splits and layers.
- Filter out unwanted MIDI messages.
- Analyse messages using the MIDI monitor.
- Map pitchbend to aftertouch.
- Setup a velocity curve for your master keyboard.
- Auto save.
Lowlights:
- Only DIN MIDI, no USB MIDI.
- Due to the limitations of the Midiboy, Roudi is somewhat limited in functionality and ease of use.
Most of the program storage space is used by Roudi, so, it will be quite hard to add extra functionality.
New features:
- MONITOR - Pitch bend is no longer shown in the [-8192, 8191] range, but in the [-64, 63] range with the raw 14-bit value in between brackets.
Bug fixes:
- Corrected #include "screen.h" to #include "Screen.h".
First public release.
New features:
- Autosave of last used play page.
- SETTINGS - Added a page to edit velocity curves.
- MULTI - The split note can now be set using the keyboard.
- MULTI - Pitch bend can now be mapped to channel aftertouch, by setting the "Pitch bend" value to "at". This is useful if your master keyboard does not send aftertouch.
Initial release (private)
Roudi listens on a single input channel and converts its messages to output messages on other channels.
It is probably best to start with setting that Input channel. To do this:
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Connect the DIN MIDI output of your master keyboard to the MIDI IN of your Midiboy.
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Connect the MIDI OUT of your Midiboy to your synths, MIDI thru box, ...
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Switch on the Midiboy. You'll see the SINGLE page:
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Press and release A + B combined to switch to the utility pages.
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Press B until you are in the SETTINGS page:
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Using the left or right buttons, set the Input channel to the output channel of your connected master keyboard.
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There is no need to save anything. The setting is instantly activated.
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Switch back to the SINGLE page by pressing and releasing A + B combined.
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You can now switch the output channel using the up and down buttons.
Roudi is based on pages. These are screens that do stuff. Use
- A to go to the previous page.
- B to go to the next page.
Roudi has two types of pages:
- Play pages: pages for playing music (SINGLE, MULTI, ...)
- Utility pages: pages for monitoring and setting up Roudi (SETTINGS, MONITOR, ...)
You can switch between the two types by pushing (and quickly releasing) A + B combined.
Inside the pages, you can use:
- left and right to modify values.
- up and down to switch between fields and/or scroll up and down.
These pages are used when you want to play music.
Press and release A+B to switch to the Utility pages.
Use this page if you just want to directly play a single instrument.
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Use up and down to move up and down through the list. Selecting a channel will route the output to that channel.
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A special value none is available that blocks the input channel. This is useful if you just want to play the built-in sound generator of your master keyboard without sending MIDI to another synth.
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At the bottom, there is a > Panic! entry which can be used like a MIDI Panic Button by pushing left or right on it. If at any time notes get stuck on your equipment, using panic should silence them.
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When you have selected one of the 16 channels you can change its name by pushing either left or right. You'll see the following page pop up:
- Use left and right to move the cursor.
- Use up and down on the text field to cycle through possible characters. You can use spaces (keep on pushing up). The name ends at the first underscore (keep on pushing down).
- To save the name, push up or down on the v.
- To cancel the naming, push up or down on the X.
- An interesting feature is that you can change the channel to which you want to save the name. Do this by pushing up and down on the ch?? field. This is particularly useful if you are moving a synth to a new channel.
Use this page if you want to combine two instruments/sounds at the same time.
You can also use it to have more control over a single instrument.
As an added benefit, you can save several MULTIs, up to 12 to be exact. This can be useful as you might want to recall a specific setup now and then. Every new MULTI becomes a new page. As with the other pages, you use the A and B buttons to switch between them. All MULTIes have a name and a number.
- Use up and down to jump between fields. left and right to change values.
- Mode:
- split splits the keyboard in two, the lower notes going to the Left channel, the higher to the Right.
- layer sends all notes to both Left and Right channel.
- left sends only to the Left channel.
- right sends only to the Right channel.
- Split at: Only available when Mode is set to split, this defines the key on the keyboard where the higher notes start. You can set it either by changing the value using the left and right buttons or by pressing a key on the keyboard.
(Be aware that you cannot play properly when you have selected Split At, because Roudi will be constantly updating its value.) - Left: The channel known as the left channel.
- Right: The channel known as the right channel. (If you select the same right channel as the left channel when in layer of split mode, only the left channel will be used.)
- The next fields are all double. The value to the left concerns the left channel, the other one the right channel.
- Octave: Transpose the channel up or down by the specified amount of octaves. (Sorry, no semitones.)
- Pitch bend: Enable (on) or disable (off) routing pitch bend to the channel. Or map pitch bend to channel aftertouch (at). The latter is useful when your master keyboard does not send aftertouch, but you want to check the aftertouch functionality of a MIDI device. (Overrides the pitch bend filter in the SETTINGS.)
- Mod wheel: Enable (on) or disable (off) routing mod wheel to the channel. (Overrides the mod wheel filter in the SETTINGS.)
- Control change: Enable (on) or disable (off) routing control change messages to the channel. (Overrides the cc filter in the SETTINGS.)
- Min velocity, Max velocity: Specify the velocity interval of the notes that should be routed to the output channel. This is mostly used when Mode is set to layer, because it allows you e.g. to trigger the right channel only for "loud" notes.
- More to the bottom you'll notice some specific commands that can be activated by pressing left or right button om them.
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New: Create an new MULTI called "MULTI" and switch to it.
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Move left or right: Is used to change the order of your MULTIes. Press the left or right button to move the current MULTI up or down in the list. You'll notice its number changes.
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Save as ...: Pops up a new menu that allows you to (a) name the MULTI, (b) copy it to an existing MULTI or (c) copy it to a new MULTI.
See SINGLE on how to edit and save the name. MULTIs cannot contain lowercase characters.
(b) and (c) are achieved by changing the mul?? value. If you have a total of four MULTIs, there will be a mul05 value that you can use to save to new slot. -
Remove ...: Pops up a conformation dialogue to allow you to remove the current MULTI. (Note that you cannot remove the last remaining MULTI.)
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- At the bottom, there is a > Panic! entry which can be used like a MIDI Panic Button by pushing left or right on it. If at any time notes get stuck on your equipment, using panic should silence them.
Some information about Roudi.
And some very basic help.
On this page, the input channel is blocked. This is the same as "None" on the SINGLE page.
These pages are used when you want to monitor MIDI messages or setup Roudi.
NOTE: When you are in a utility page, the MIDI routing defined by the play page from which you switched stays active.
Press and release A+B to switch back to the Play pages.
Configure Roudi.
Changes are immediately active and saved.
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Input channel: Select the input channel that will be routed to the output. This is typically the output MIDI channel of you master keyboard connected to the MIDI IN of Midiboy.
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Block other input channels: Specify whether you want to have Roudi block all input channels other than the one set in Input channel.
In both cases, messages on the Input channel are routed according to the active SINGLE or MULTI.- If set to no, incoming MIDI messages on other channels are passed to the output channel with the same number.
- If set to yes, incoming MIDI messages on other channels are discarded.
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Velocity curve: Select the velocity curve to use. By default this is a linear mapping: notes with velocity n are also output with velocity n. Next to linear, three user defined velocity curves are available.
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Velocity curve edit: You can edit the user defined velocity curves by pushing left or right. This pops up a new menu.
Choose one of the user 1/2/3 curves to edit by pushing left or right on them. (You cannot modify linear.)
This pops up the VELOCITY CURVE EDIT menu:
It has the following elements:
- The name of the curve you are editing.
- X axis representing the input velocity.
- Y axis representing the output velocity.
- The curve representing the mapping from input to output velocity.
- The cursor used to modify the curve. Use left and right to move to another X position.
Use up and down to move the curve up and down at that position,... - ... you'll see the (x, y) value of that position, meaning if you would strike a key at velocity x it will be sent to the output at velocity y.
- The page is interactive in a way that when you strike a key, its input velocity will be drawn with a vertical dotted line ...
- ... and the input velocity and output velocity is shown at the right.
- If you move the cursor further to the right you can use up or down to
- save the curve and exit when on 'v'
- exit without saving (=cancel) when on 'X'
- reset the curve to linear, when on '/'
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Screen brightness: By default, Roudi uses full brightness, but you can lower this if so required.
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Input channel filter: Controls whether to route particular types of MIDI messages to the output:
- pass means that they are send to the output
- block means that they are NOT send to the output
The following messages can be filtered
- Note on/off: played notes
- Pitch bend: pitch bend wheel
- Channel pressure: also called channel aftertouch
- Key pressure: also called polyphonic aftertouch
- Program change: controls the program change (but not the bank change, which is implemented through CC#0!)
- Mod wheel: modulation wheel (this is actually implemented through CC#1)
- All other CC: continuous control change messages, except for CC#1
- Time sync: MIDI clock (F8) and MIDI time code frame (F1)
- Transport: start (FA), continue (FB), stop (FC), song position (F2) and song select (F3)
- System exclusive: system exclusive messages (F0 and F7)
- Active sensing: I'm still alive message (FE)
- Other: Tune request (F0) and system reset (FF)
Display incoming and outgoing MIDI messages. A very useful tool for debugging your MIDI setup.
Each line is either an incoming or outgoing MIDI message. They contain the following elements:
- 'i' for input message or 'o' for output message
- channel number
- name and value of the MIDI message
In case of control change messages, the CC number is translated into its typical use.
A lot of information can be deduced from the monitor, as shown in the image above:
You'll see that an A4 is played on channel 1 at velocity 76.
This is routed to two output channels: 3 and 4. This is because a MULTI is being used in layer mode.
The velocity mapping being used is not linear as the output velocities are 80.
You can also see that the note sent to channel 4 is transposed up an octave.
The note offs have their own velocity, the release velocity. This is atypical since most keyboards do not measure this value.After the played note, a control change message #7 with value 84 is sent to both output channels.
CC#7 by default controls the volume of a connected device. If the devices on channel 3 and 4 support this CC, they'll change their volume.
You can scroll through the messages using up and down.
Every time you switch away from this page, the buffer is cleared.
System exclusive is currently not displayed.
Configure the MIDI MONITOR page.
MIDI devices can generate enormous amounts of messages in a short time. To make it easier to focus on the interesting ones, this page allows filtering out the unwanted ones.
To be clear, these messages are still received/sent, just not displayed in the monitor.
(Note that you can truly filter output messages in the SETTINGS page.)
- Channels to show: Select whether you want to display
- all channels: displays the messages of all 16 input and output channels
- routed channels: only displays the input messages of the Input channel (set in the SETTINGS page) and the output messages of the output channel(s) to which the input channel is currently routed
- IO to show: Select whether to show both input and output messages, only input messages or only output messages.
- Messages: Select which particular messages are displayed. If you press left or right here, hide and show are toggled for all message types at once.
- Note on: struck notes
- Note off: released notes
- Pitch bend: pitch bend wheel
- Channel pressure: also called channel aftertouch
- Key pressure: also called polyphonic aftertouch
- Program change: program change (but not the bank change, which is implemented through CC#0!)
- Control change: continuous control change messages, including modulation wheel
- Time sync: MIDI clock (F8) and MIDI time code frame (F1)
- Transport: start (FA), continue (FB), stop (FC), song position (F2) and song select (F3)
- System exclusive: system exclusive messages (F0 and F7)
- Active sensing: I'm still alive message (FE)
- Other: Tune request (F0) and system reset (FF)
- All changes you make are saved automatically. Most of the time, this is really great. Sometimes it is annoying, but this design choice was made to keep things easy and clear.
- The MIDI configuration active on the play page remains active on the utility page. So, e.g. if you are on a MULTI and you switch to the MONITOR, you'll see the output of the MULTI routing.
- There are two conventions for numbering notes in MIDI:
- MIDI note 60 = C3
- MIDI note 60 = C4 = middle C = 261.63Hz, MIDI note 69 = A4 = 440.00Hz
We chose this convention.
- If you change the MIDI channels of your MIDI instruments, its Roudi channel name will no longer correspond. The easiest way to correct is, is to go into the old name in SINGLE and save it to the new channel number.
- Every time you change the midi configuration, for instance by selecting a channel in single or multi, changing octave, velocity, setting, ... note offs are sent to all active MIDI channels. So, basically when you change stuff, any note you are holding on your keyboard will be terminated.
- Panic is implemented by sending an All Sound Off message to all 16 output channels. Sadly, not all synthesizers have a full MIDI implementation and might ignore the All Sound Off message.
If you'd like to have a case for Midiboy and have access to a 3D printer, you can use one of the stls available in the cases folder of this repository.
They are also available on Thingiverse.
There is a basic case (called A) and a more advanced one (as seen in the image below, called B).
Note that the repo also contains some stls to print out a stand to tilt the device.
Entry into the program is through Roudi.ino.
You need to setup your environment as discussed by Blokas in:
I use Microsoft VS Code as my editor.
It has an Arduino extension that you can configure to run with its bundled Arduino CLI.
Roudi.h contains several DEFINEs that can be enabled or disabled to control Roudi's configuration.
They are mostly concerned with memory usage, debugging and default values.
The microcontroller used in Midiboy only has 2 KB of RAM and 32 KB of program space.
I tried to work around these limits as much as possible. In some parts of the sources, this resulted in some weird and not so pretty code.
Recently, I was able to free some RAM.
However most of the program space has been used up.
This makes it difficult to add new features in the future.
- Have values on pages cycle?
- The filter for program change should include the bank change (which is implemented as CC0).
- More extended CC filtering and mapping. => Don't have enough memory for that, I'm afraid.
- Rename SINGLE to SIMPLE and MULTI to ADVANCED?
- Show SysEx in Monitor?
There is a more technical todo list in docs/Todo.txt
- Roudi by Headphone Cairn Software.
- MIDI library and more by Blokas.
- Released under GNU GENERAL PUBLIC LICENSE Version 2.