florian
2014-10-24 10:43:45
A user has this problem: the foot pedal only produces controller values between 40 and 70 (decimal). It should, however, control a controller with the full value range from 0 to 127.
The solution (in detail):
1) set up MT as "man in the middle", i.e. the external MIDI port is used by MT. It will route the calibrated MIDI data via the virtual MIDI port to the application where you want to use the pedal. The user manual describes this setup in the introductory chapters.
2) create a route in the MIDI Router so that by default all messages from the pedal are routed to the virtual port:
External MIDI Input --> Bome Virtual Out 1
(If you have multiple pedals, you can also merge all inputs to one virtual MIDI port by creating routes from the external ports to the same virtual output, or map each pedal to an individual virtual output).
3) create a preset, e.g. named "scale pedal 1". Invoke the preset properties and select the preset default MIDI ports: your External MIDI Input port as input, and the virtual output port 1 as output.
4) create a mapping by adding a translator in the preset. In the general options, make sure the "swallow" checkbox is checked. Assuming that the pedal sends on MIDI controller #0, the incoming and outgoing actions look like this:Like that, the translator will simply output the same message that came in to the input port. The variable "pp" is a place holder for the controller value.
5) Use the rules for the actual calibration/scaling: the rules now have the task to "blow up" the value range from 40...70 to 0...127. This requires a bit math:(Note that actually, the ranges should be increased +1, but this causes an undesirable maximum scaled value).
When we put in the actual values, it looks a whole lot simpler:
Here, we need to be careful, though: MT's variables only handle integer numbers, no fractions or decimals. Therefore, dividing by 30 will truncate the value and cause huge rounding errors. The solution is to always do the multiplication first, and then the division:
The final rules section looks like this:
As you can see, the rules in MT can only evaluate one mathematical statement per line. I've also added safeguards to not produce a controller value out of bounds. When all the rules are executed, pp has the full range value, i.e. something in between 0 and 127.
Hope this gets you started!
Florian
The solution (in detail):
1) set up MT as "man in the middle", i.e. the external MIDI port is used by MT. It will route the calibrated MIDI data via the virtual MIDI port to the application where you want to use the pedal. The user manual describes this setup in the introductory chapters.
2) create a route in the MIDI Router so that by default all messages from the pedal are routed to the virtual port:
External MIDI Input --> Bome Virtual Out 1
(If you have multiple pedals, you can also merge all inputs to one virtual MIDI port by creating routes from the external ports to the same virtual output, or map each pedal to an individual virtual output).
3) create a preset, e.g. named "scale pedal 1". Invoke the preset properties and select the preset default MIDI ports: your External MIDI Input port as input, and the virtual output port 1 as output.
4) create a mapping by adding a translator in the preset. In the general options, make sure the "swallow" checkbox is checked. Assuming that the pedal sends on MIDI controller #0, the incoming and outgoing actions look like this:
Code: Select all
Incoming: MIDI C0 00 pp
Outgoing: MIDI C0 00 pp
5) Use the rules for the actual calibration/scaling: the rules now have the task to "blow up" the value range from 40...70 to 0...127. This requires a bit math:
Code: Select all
(small_range_value - small_range_min)
full_range_value = --------------------------------------- * (full_range_max - full_range_min)
(small_range_max - small_range_min)When we put in the actual values, it looks a whole lot simpler:
Code: Select all
full_range_value = (small_range_value - 40) / 30 * 127Code: Select all
full_range_value = (small_range_value - 40) * 127 / 30Code: Select all
pp=pp-40
if pp < 0 then pp=0
pp=pp*127
pp=pp/30
if pp > 127 then pp=127Hope this gets you started!
Florian