USB driver for SourceAudio C4 Synth pedal

M

MichaelMC

Well-known member
Hello folks,

Attached is a first revision of a Teensy 3.6+ USB driver & library for the C4 synth pedal from Source Audio.
What this driver & library will allow one to do, is to fully control every aspect of your synth pedal. From activating a Preset to adjusting the various controls (variables) of that preset - in real time.
This is the initial release and with that, a bare bones project from which to base your own project upon. There is but one example; but feature packed, demonstrating various possibilities - TeensyC4.ino.

The library is split in to 3 components:
USB communication functionality: c4_drv.cpp
Pedal accessor functions: sa_c4.c
Utility functions which wrap around the accessors: util.c

There should never be a need to adjust anything within c4_drv.cpp nor sa_c4.c. It's expected that you will modify the utility functions to suit your requirements.
A future release could support other Source Audio Pedals as I believe they're built upon a similar, if not the same, framework.
Tested on Teensy 3.6 and 4.1 - Teensyduino 1.5.8 with Arduino 1.8.5 and with C4 firmware 1.20 and 1.21.


Any issues, comments, etc.. please post in this thread to grab my attention.

Version 1.0:260423 - View attachment TeensyC4-260423.zip


For reference, this is the output of the example .ino with my own pedal:
Code: 
Source Audio C4 demo

 - C4 Synth ready -

Hardware Config:
Firmware: 1.21
Device model: 249
Number of presets: 128
Active preset: 3
Preset/WYSIWYG: 0
Hardware bypass mode: 0
Midi channel (1 to 16): 2
Ccontrol input option: 0
External loop safe mode: 0
Power up state: 0
Default input routing: 0
Quick bank select: 0
Neuro hub pedel input calibration Min: 0
Neuro hub pedel input calibration Range: 1023
Control input calibration Min: 410
control input calibration Range: 240
USB-Midi skip power check: 1





Presets:
 001: Turn Away Wah
 002: voice sound
 003: DBX 11
 004: Poly Pitch Swell
 005: Funk Dragon
 006: Flashlight Bass
 007: slow attack  si/sq filter
 008: thriller bass
 009: Bass in Baby
 010: Kevo's Dirty Synth 2.0
 011: my new preset
 012: Spacedock
 013: Saturday Cinema
 014: NC - Phaser
 015: Set Phasers To Kill 1
 016: Lazer Disco
 017: NIck Campbell Chords
 018: Future Nostalgia
 019: Don't Start Now
 020: Canned Heat
 021: Thriller
 022: Above & Beyond EXP
 023: Just Can't Get Enough
 024: Axel F
 025: Nuno Synth
 026: Mu-Tron Micro-Tron IV 10
 027: chaka chan
 028: --empty--
 029: das model bass
 030: kraftwerk model melody
 031: das model pulse
 032: das model alt melody
 033: the message
 034: Kavinsky triad
 035: kavinsky arp
 036: QM Chordially Invited 1
 037: QM Only On Paper 1
 038: QM Tom Sawyer 2
 039: QM Frustrations of Yesteryear 3a
 040: Spectrum - Split Octaves
 041: Spectrum - Gated Phaser
 042: Spectrum - Bandpass
 043: Spectrum - Dumpling
 044: Spectrum - Tron
 045: C minor Harmony and Sequencer
 046: Da Funk
 047: Meatball - Low Pass 1
 048: Moog Taurus (Winter NAMM 2019)
 049: Spaceship Overhead
 050: The Kraken Approaches
 051: External Loop Template
 052: EDM Swell
 053: Machine Octaves
 054: Machine Octaves 2
 055: Funk Dragon
 056: Right Meow
 057: Myriads Rise
 058: Initialize - Bass
 059: 808
 060: Synth Bass
 061: Lush Pad
 062: Sweep & Weep
 063: Simple Bit Crusher
 064: HC Moog 1
 065: Rhythmic Bass Octave Arpeggiator
 066: Microsynth
 067: OC-2 Synth
 068: 808 BASS
 069: Black Coffee
 070: All there is
 071: TeensyTest
 072: Kinda Jerry
 073: Moog Bass Synth - Jim 1
 074: 12 String-esque
 075: Take My Breath Away Bass
 076: EnvPhaser
 077: Tremvelope
 078: Clean Octave
 079: Whoow
 080: Ambient bass
 081: 24K MOOG
 082: Hysteria bass
 083: MF-101
 084: Deep Source - Hardcore
 085: Tower of Fuzz
 086: BladeRunnerBrass
 087: OctoFilterFunk
 088: 106 Jellybeans
 089: Qtron Fuzz
 090: Pony (modifed)
 091: Rotary Sim
 092: Deep Source - Dark Bubble
 093: 3-Stage Phaser
 094: Interstella Arcade
 095: A Stranger Sequence
 096: Blue Monday Low & Nasty
 097: Poly Pitch Swell
 098: ChordStabs
 099: Technologic
 100: Ensemble Brass & Reed
 101: Poly Pitch Swell 2
 102: Tron-Sitar
 103: BubblyTron
 104: C 7th Chords
 105: Saw Envelope
 106: Red Alert
 107: PHAT LEAD
 108: Clockwork Orange
 109: 808 Kick Bass
 110: Droid Pulsar
 111: Arrival
 112: Wind Sound
 113: SYNTH - Taurus
 114: HC Moog 1 Oct Up
 115: Chicago Warehouse
 116: AcidSeq
 117: Zelda's Dungeon
 118: Pro moog 3
 119: James & The Giant Fuzz
 120: house synth
 121: Bassballs Type 23
 122: Slime Phase
 123: Sean Murray - D&B Swell
 124: Shallow Impact II
 125: QM 3-OSC RAW filtered 3
 126: Chaves
 127: HP42 Pluck + Oct Sequence
 128: Lyle's OB Flutes


Current control values of active preset:
input1_gain            72
input2_gain            183
master_depth           254
mod_source             17
bass                   154
treble                 123
mix                    123
lo_retain              0 
output                 42
output_balance         127
voice1_level           34
voice1_pan             110
voice1_detune          129
voice1_tremolo         3 
voice1_octave          6 
voice1_semitone        11
voice1_mode            0 
voice1_source          7 
voice1_envelope        1 
voice1_destination     0 
voice1_tremolo_source  0 
voice1_modulate        0 
voice1_enable          1 
voice2_level           182
voice2_pan             99
voice2_detune          125
voice2_tremolo         0 
voice2_octave          5 
voice2_semitone        4 
voice2_mode            0 
voice2_source          8 
voice2_envelope        1 
voice2_destination     0 
voice2_tremolo_source  0 
voice2_modulate        1 
voice2_enable          1 
voice3_level           32
voice3_pan             132
voice3_detune          126
voice3_tremolo         0 
voice3_octave          5 
voice3_semitone        20
voice3_mode            0 
voice3_source          9 
voice3_envelope        2 
voice3_destination     1 
voice3_tremolo_source  0 
voice3_modulate        0 
voice3_enable          1 
voice4_level           94
voice4_pan             119
voice4_detune          125
voice4_tremolo         0 
voice4_octave          5 
voice4_semitone        11
voice4_mode            0 
voice4_source          10
voice4_envelope        2 
voice4_destination     1 
voice4_tremolo_source  0 
voice4_modulate        1 
voice4_enable          1 
distortion_drive       112
distortion_mix         172
distortion_output      20
distortion_type        10
distortion_enable      1 
filter1_depth          139
filter1_frequency      64
filter1_q              10
filter1_type           0 
filter1_envelope       0 
filter1_invert         0 
filter1_enable         1 
filter1_pitch_track    0 
mix1_destination       0 
filter2_depth          81
filter2_frequency      172
filter2_q              158
filter2_type           19
filter2_envelope       1 
filter2_invert         0 
filter2_enable         1 
filter2_pitch_track    0 
mix2_destination       0 
envelope1_sensitivity  254
envelope1_speed        155
envelope1_gate         5 
envelope1_type         2 
envelope1_input        0 
envelope2_sensitivity  228
envelope2_speed        15
envelope2_gate         9 
envelope2_type         5 
envelope2_input        0 
fm_sine1               6 
fm_sine2               2 
fm_sine1_input         1 
fm_sine2_input         1 
mono_pitch_filter1     127
mono_pitch_filter2     127
lfo_speed              0 
lfo_env_to_speed       214
lfo_env_to_depth       79
lfo_2_phase            92
lfo_2_multiply         3 
lfo_shape              4 
lfo_restart            1 
lfo_beat_division      3 
lfo_tempo              0 
sequencer1_steps       14
sequencer1_value0      24
sequencer1_value1      24
sequencer1_value2      37
sequencer1_value3      36
sequencer1_value4      24
sequencer1_value5      34
sequencer1_value6      24
sequencer1_value7      34
sequencer1_value8      31
sequencer1_value9      24
sequencer1_value10     24
sequencer1_value11     32
sequencer1_value12     24
sequencer1_value13     24
sequencer1_value14     29
sequencer1_value15     28
sequencer2_steps       14
sequencer2_value0      24
sequencer2_value1      36
sequencer2_value2      24
sequencer2_value3      36
sequencer2_value4      48
sequencer2_value5      36
sequencer2_value6      24
sequencer2_value7      36
sequencer2_value8      36
sequencer2_value9      36
sequencer2_value10     24
sequencer2_value11     36
sequencer2_value12     24
sequencer2_value13     24
sequencer2_value14     36
sequencer2_value15     24
harmony_tuning         100
harmony_key            0 
harmony_mode           0 
harmony_interval1      0 
harmony_interval2      0 
pitch_detect_input     0 
pitch_detect_low_note  20
pitch_detect_high_note 21
knob1_assign           29
knob2_assign           7 
filter2_correction     0 
ext1_destination       34
ext1_source            1 
ext1_min               0 
ext1_max               254
ext2_destination       35
ext2_source            1 
ext2_min               0 
ext2_max               127
ext3_destination       36
ext3_source            1 
ext3_min               127
ext3_max               254
ext_control_enable     0 
lfo_midi_clock_sync    0 
pitch_detect_mode      0 
mix1_enable            1 
mix2_enable            1 
routing_option         0 
on_off_status          1 


Reading: Output volume level:
42


Writing: Setting output level to 75:
output set to 75


Reading: Output volume level:
75


Selecting preset 1:
Preset 1 selected


Active Preset:
1: Turn Away Wah                  


Selecting next preset:
2: voice sound                    


Active preset is now:
2: voice sound                    


Preset 3 selected
Printing binary data for preset 3:
48 B7 FE 11 9A 7B 7B 00 2A 7F 22 6E 81 03 5E 5C 18 B6 63 7D 00 25 60 1C 20 84 7E 00 A5 A4 11 5E
77 7D 00 5D A8 15 8B 40 0A 80 10 51 AC 9E B3 10 FE 9B 05 02 E4 0F 09 05 70 AC 14 1A 06 02 03 7F
7F 00 D6 4F 5C 03 74 00 00 00 00 0E 18 18 25 24 18 22 18 22 1F 18 18 20 18 18 1D 1C 0E 18 24 18
24 30 24 18 24 24 24 18 24 18 18 24 18 64 00 00 50 15 1D 07 10 62 00 FE 63 00 7F 64 7F FE 00 00
44 42 58 20 31 31 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20 20
00 00 00 00



Printing .pre (XML) for preset 3:

<neuro_preset>
    <info>
        <product_id>249</product_id>
        <preset_name>DBX 11</preset_name>
    </info>
    <input1_gain>72</input1_gain>
    <input2_gain>183</input2_gain>
    <master_depth>254</master_depth>
    <mod_source>17</mod_source>
    <bass>154</bass>
    <treble>123</treble>
    <mix>123</mix>
    <lo_retain>0</lo_retain>
    <output>42</output>
    <output_balance>127</output_balance>
    <voice1_source>7</voice1_source>
    <voice1_envelope>1</voice1_envelope>
    <voice1_octave>6</voice1_octave>
    <voice1_semitone>11</voice1_semitone>
    <voice1_mode>0</voice1_mode>
    <voice1_level>34</voice1_level>
    <voice1_pan>110</voice1_pan>
    <voice1_tremolo>3</voice1_tremolo>
    <voice1_tremolo_source>0</voice1_tremolo_source>
    <voice1_detune>129</voice1_detune>
    <voice1_modulate>1</voice1_modulate>
    <voice1_destination>0</voice1_destination>
    <voice1_enable>1</voice1_enable>
    <voice2_source>8</voice2_source>
    <voice2_envelope>1</voice2_envelope>
    <voice2_octave>5</voice2_octave>
    <voice2_semitone>4</voice2_semitone>
    <voice2_mode>0</voice2_mode>
    <voice2_level>182</voice2_level>
    <voice2_pan>99</voice2_pan>
    <voice2_tremolo>0</voice2_tremolo>
    <voice2_tremolo_source>1</voice2_tremolo_source>
    <voice2_detune>125</voice2_detune>
    <voice2_modulate>1</voice2_modulate>
    <voice2_destination>0</voice2_destination>
    <voice2_enable>1</voice2_enable>
    <voice3_source>9</voice3_source>
    <voice3_envelope>2</voice3_envelope>
    <voice3_octave>5</voice3_octave>
    <voice3_semitone>20</voice3_semitone>
    <voice3_mode>0</voice3_mode>
    <voice3_level>32</voice3_level>
    <voice3_pan>132</voice3_pan>
    <voice3_tremolo>0</voice3_tremolo>
    <voice3_tremolo_source>0</voice3_tremolo_source>
    <voice3_detune>126</voice3_detune>
    <voice3_modulate>0</voice3_modulate>
    <voice3_destination>1</voice3_destination>
    <voice3_enable>1</voice3_enable>
    <voice4_source>10</voice4_source>
    <voice4_envelope>2</voice4_envelope>
    <voice4_octave>5</voice4_octave>
    <voice4_semitone>11</voice4_semitone>
    <voice4_mode>0</voice4_mode>
    <voice4_level>94</voice4_level>
    <voice4_pan>119</voice4_pan>
    <voice4_tremolo>0</voice4_tremolo>
    <voice4_tremolo_source>1</voice4_tremolo_source>
    <voice4_detune>125</voice4_detune>
    <voice4_modulate>0</voice4_modulate>
    <voice4_destination>1</voice4_destination>
    <voice4_enable>1</voice4_enable>
    <filter1_depth>139</filter1_depth>
    <filter1_frequency>64</filter1_frequency>
    <filter1_q>10</filter1_q>
    <filter1_type>0</filter1_type>
    <filter1_invert>0</filter1_invert>
    <filter1_envelope>0</filter1_envelope>
    <filter1_pitch_track>0</filter1_pitch_track>
    <filter1_enable>1</filter1_enable>
    <mix1_destination>0</mix1_destination>
    <mix1_enable>1</mix1_enable>
    <filter2_depth>81</filter2_depth>
    <filter2_frequency>172</filter2_frequency>
    <filter2_q>158</filter2_q>
    <filter2_type>19</filter2_type>
    <filter2_invert>0</filter2_invert>
    <filter2_envelope>1</filter2_envelope>
    <filter2_pitch_track>0</filter2_pitch_track>
    <filter2_enable>1</filter2_enable>
    <mix2_destination>0</mix2_destination>
    <mix2_enable>1</mix2_enable>
    <envelope1_speed>155</envelope1_speed>
    <envelope1_sensitivity>254</envelope1_sensitivity>
    <envelope1_gate>5</envelope1_gate>
    <envelope1_type>2</envelope1_type>
    <envelope1_input>0</envelope1_input>
    <envelope2_speed>15</envelope2_speed>
    <envelope2_sensitivity>228</envelope2_sensitivity>
    <envelope2_gate>9</envelope2_gate>
    <envelope2_type>5</envelope2_type>
    <envelope2_input>0</envelope2_input>
    <distortion_drive>112</distortion_drive>
    <distortion_mix>172</distortion_mix>
    <distortion_output>20</distortion_output>
    <distortion_type>10</distortion_type>
    <distortion_enable>1</distortion_enable>
    <lfo_speed>0</lfo_speed>
    <lfo_env_to_speed>214</lfo_env_to_speed>
    <lfo_env_to_depth>79</lfo_env_to_depth>
    <lfo_2_phase>92</lfo_2_phase>
    <lfo_shape>4</lfo_shape>
    <lfo_restart>1</lfo_restart>
    <lfo_2_multiply>3</lfo_2_multiply>
    <lfo_beat_division>3</lfo_beat_division>
    <fm_sine1>6</fm_sine1>
    <fm_sine2>2</fm_sine2>
    <fm_sine1_input>1</fm_sine1_input>
    <fm_sine2_input>1</fm_sine2_input>
    <mono_pitch_filter1>127</mono_pitch_filter1>
    <mono_pitch_filter2>127</mono_pitch_filter2>
    <lfo_tempo>0</lfo_tempo>
    <lfo_midi_clock_sync>0</lfo_midi_clock_sync>
    <sequencer1_steps>16</sequencer1_steps>
    <sequencer1_value0>24</sequencer1_value0>
    <sequencer1_value1>24</sequencer1_value1>
    <sequencer1_value2>37</sequencer1_value2>
    <sequencer1_value3>36</sequencer1_value3>
    <sequencer1_value4>24</sequencer1_value4>
    <sequencer1_value5>34</sequencer1_value5>
    <sequencer1_value6>24</sequencer1_value6>
    <sequencer1_value7>34</sequencer1_value7>
    <sequencer1_value8>31</sequencer1_value8>
    <sequencer1_value9>24</sequencer1_value9>
    <sequencer1_value10>24</sequencer1_value10>
    <sequencer1_value11>32</sequencer1_value11>
    <sequencer1_value12>24</sequencer1_value12>
    <sequencer1_value13>24</sequencer1_value13>
    <sequencer1_value14>29</sequencer1_value14>
    <sequencer1_value15>28</sequencer1_value15>
    <sequencer2_steps>16</sequencer2_steps>
    <sequencer2_value0>24</sequencer2_value0>
    <sequencer2_value1>36</sequencer2_value1>
    <sequencer2_value2>24</sequencer2_value2>
    <sequencer2_value3>36</sequencer2_value3>
    <sequencer2_value4>48</sequencer2_value4>
    <sequencer2_value5>36</sequencer2_value5>
    <sequencer2_value6>24</sequencer2_value6>
    <sequencer2_value7>36</sequencer2_value7>
    <sequencer2_value8>36</sequencer2_value8>
    <sequencer2_value9>36</sequencer2_value9>
    <sequencer2_value10>24</sequencer2_value10>
    <sequencer2_value11>36</sequencer2_value11>
    <sequencer2_value12>24</sequencer2_value12>
    <sequencer2_value13>24</sequencer2_value13>
    <sequencer2_value14>36</sequencer2_value14>
    <sequencer2_value15>24</sequencer2_value15>
    <pitch_detect_input>0</pitch_detect_input>
    <pitch_detect_low_note>20</pitch_detect_low_note>
    <pitch_detect_high_note>21</pitch_detect_high_note>
    <pitch_detect_mode>0</pitch_detect_mode>
    <harmony_key>0</harmony_key>
    <harmony_tuning>100</harmony_tuning>
    <harmony_mode>0</harmony_mode>
    <harmony_interval1>0</harmony_interval1>
    <harmony_interval2>0</harmony_interval2>
    <knob1_assign>29</knob1_assign>
    <knob2_assign>7</knob2_assign>
    <ext1_source>1</ext1_source>
    <ext1_destination>34</ext1_destination>
    <ext1_min>0</ext1_min>
    <ext1_max>254</ext1_max>
    <ext2_source>1</ext2_source>
    <ext2_destination>35</ext2_destination>
    <ext2_min>0</ext2_min>
    <ext2_max>127</ext2_max>
    <ext3_source>1</ext3_source>
    <ext3_destination>36</ext3_destination>
    <ext3_min>127</ext3_min>
    <ext3_max>254</ext3_max>
    <ext_control_enable>0</ext_control_enable>
    <routing_option>0</routing_option>
    <on_off_status>1</on_off_status>
    <filter2_correction>0</filter2_correction>
</neuro_preset>



Printing preset values for preset 3:
Name: DBX 11                         
 Levels:
input1_gain    72
input2_gain    183
master_depth   254
mod_source     17
bass           154
treble         123
mix            123
lo_retain      0
output         42
output_balance 127

 Filter: 1
depth           139
frequency       64
q               10
type            0
envelope        0
invert            0
enable            1
pitch_track     0
mix_destination 0
mix_enable      1

 Filter: 2
depth           81
frequency       172
q               158
type            19
envelope        1
invert            0
enable            1
pitch_track     0
mix_destination 0
mix_enable      1

 Envelope: 1
sensitivity    254
speed          155
gate           5
type;          2
input          0

 Envelope: 2
sensitivity    228
speed          15
gate           9
type;          5
input          0

 Distortion:
drive             112
mix               172
output            20
type              10
enable            1

fm_sine1           6
fm_sine2           2
fm_sine1_input     1
fm_sine2_input     1
mono_pitch_filter1 127
mono_pitch_filter2 127

 LFO:
speed             0
env_to_speed      214
env_to_depth      79
to_phase          92
to_multiply       3
shape             4
restart           1
beat_division     3
tempo             0

 Sequencer: 1
steps          16
value 1       24
value 2       24
value 3       37
value 4       36
value 5       24
value 6       34
value 7       24
value 8       34
value 9       31
value 10       24
value 11       24
value 12       32
value 13       24
value 14       24
value 15       29
value 16       28

 Sequencer: 2
steps          16
value 1       24
value 2       36
value 3       24
value 4       36
value 5       48
value 6       36
value 7       24
value 8       36
value 9       36
value 10       36
value 11       24
value 12       36
value 13       24
value 14       24
value 15       36
value 16       24

 Harmony:
tuning         100
key            0
interval1      0
mode           0
interval2      0

 Pitch detect:
input          0
mode           0
low_note       20
high_note      21

 General:
knob1_assign        29
knob2_assign        7
routing_option      0
filter2_correction  0
on_off_status       1
ext_control_enable  0
lfo_midi_clock_sync 0

 Ext: 1
destination 34
source      1
min         0
max         254

 Ext: 2
destination 35
source      1
min         0
max         127

 Ext: 3
destination 36
source      1
min         127
max         254



Dumping internal EEPROM:
00 00 01 00 00 00 00 00 00 00 FF 03 9A 01 F0 00
01 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
00 FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FA FF FF
FF FF FF FF F9 FF FB FE FD FC FF FF FF FF FF FF
FF FF FF FF FF FF FF FF FF FF FF FF FF FF FF F8



Searching for duplicates of preset 71..
71 <> 70: identical
Search complete


Searching for any duplicates..
3 <> 9: identical
9 <> 3: identical
70 <> 71: identical
71 <> 70: identical
Duplicates found
 
Last edited:
I know this is old but wow thanks. I have a C4 and I wish I would have seen this before I started working on an Arduino + MIDI Host shield.

BTW, someone told me you could not gather the present names off the pedal. WRONG. You're clearly doing it, nice job!
 
Last edited:
Sorry, too vague. From my reading of your code you do a callback and loop through the returned object to get all the pedal information, including the preset names. I presume that would work for Arduino boards and code, just wanted to get your opinion.

Thanks
 
mgaert said:
Sorry, too vague. From my reading of your code you do a callback and loop through the returned object to get all the pedal information, including the preset names. I presume that would work for Arduino boards and code, just wanted to get your opinion.

Thanks
Click to expand...

The API is implemented as a synchronous blocking interface; there are no callbacks to wait upon or listen for. What callbacks there are, are within the USB interface (c4_drv.cpp). Within that, there are two only. One does nothing but provide a method of signalling to the end user that the device is ready after initial power-on. The other, rx_callback(), cleans the pipe (usb endpoint) after an irregular transmit from the device. tx_callback(), which isn't used and the assignment of that callback() is commented out. I suspect this might have been the the cause of confusion.

Something to note, C4 will only transmit a full and complete payload, it will never try to transmit 'something now, and a little later, something else' leaving the end user to concatenate the result.
Also, it may be worth noting that the pedal itself is implemented as a HID device, whence the hid_xx calls you see placed around.
 
Wow, that is a lot of useful information! I used to program every day for years, but not much lately. You’re getting all the info and sending all the commands I’m interested in. When I get my HobbyTronics USB host board and Arduino Micro MIDI controller all hooked up and working with the C4 I can come back to this and try to do it with my setup.

Thanks again. If I get it to go I’ll hit you back.
 
Hi, hope you are well. Question about the C4, in very general terms what is the process to get configuration data from the pedal? I’m using a USB host board so the USB communications are basically hidden from the MIDI code. My Arduino board is successfully sending program change commands to the C4. Both Rx and Tx pins are connected via a USB cable, I’m just not sure how or where to see MIDI or text coming back. In reading through your code I don’t see any obvious ‘calls’ to or ‘reads’ of the pedal. Just wondering how you get the pedal to produce the configuration data.

Thanks for any help!
 
mgaert said:
Hi, hope you are well. Question about the C4, in very general terms what is the process to get configuration data from the pedal? I’m using a USB host board so the USB communications are basically hidden from the MIDI code. My Arduino board is successfully sending program change commands to the C4. Both Rx and Tx pins are connected via a USB cable, I’m just not sure how or where to see MIDI or text coming back. In reading through your code I don’t see any obvious ‘calls’ to or ‘reads’ of the pedal. Just wondering how you get the pedal to produce the configuration data.

Thanks for any help!
Click to expand...

Hello Mgaert,

This library is specifically intended for the Teensy 4.1 only. I can not offer any assistance for any board other than the intended target.
That being said, the library does not communicate with the C4 through MIDI messaging, but through the C4's HID interface, aka, a USB endpoint.
 
mgaert said:
Ok, thanks for your help and the clarification.
Click to expand...

Just to clarify any misunderstanding; This forum is hosted on, and by PJRC, for the Teensy range of microcontrollers', as produced by PJRC (P.S. and Co.). This is not a general Arduino forum and is intended to offer assistance for those who've purchased PJRC (Teensy) products.

Referencing your project. From what I've gathered, if the basis of the project is to build a C4 controller, which is the purpose of the library, then the Arduino Micro may not be sufficient (to put it lightly). It is quite limited in both performance & memory (SRAM @ 2.5k) and lacks USB host capability. And quite possibly you're going to encounter other limitations later, especially if you plan to have a UI (LCD).
I would recommend dumping the micro+host board combo, go direct with a Teensy 4.1, least not for anything else but for future proofing with feature creep in mind.
 
Yes, I did not fully understand the “teensy specific” aspect at the outset. I got pretty excited about your C4 library. I’m new to controller boards of any kind. You are mainly on the right about the Micro’s capabilities, but at this point here I am. The two boards together are doing most of what I want, which is scrolling through and choosing from the 128 presets. Reading the preset names from the pedal and displaying them to choose from was the final feature and now I see that may not be possible with the Micro due to memory constraints. Back when I thought it wasn’t possible to read from the pedal I had other schemes to achieve my goals and I will probably go back to them.

As I said before if I knew about your library when I started I would have gotten a Teensy. Once I complete what I can with what I have the Teensy will probably be next.

Again, thanks!
 
I posted a question to your GitHub but probably more appropriate here as it’s not an issue. I don’t see where pins are set for RX/TX and here are 8 potential RX/TX sets. What am I missing?

Also it seems that PlatformIO/VSCode doesn’t respond to sprintf be default.
 
Hello Micky,
You mentioned you picked up a Teensy 4.1 for this, so here is fine.

The C4 connects to the Teensy via the Teensy's USB host port, with this cable and as seen here : https://www.pjrc.com/store/cable_usb_host_t36.html
Grab that cable, power up the C4, power up the Teensy (I use a custom 5v USB power pack). You're now ready to upload the demo .ino.
 
mgaert said:
I posted a question to your GitHub but probably more appropriate here as it’s not an issue. I don’t see where pins are set for RX/TX and here are 8 potential RX/TX sets. What am I missing?

Also it seems that PlatformIO/VSCode doesn’t respond to sprintf be default.
Click to expand...
Let's start with the first serial port on pins 1&2, this is addressed as Serial1, so Serial1.begin(11520); works.
Likewise for the second serial port on pins 7&8, this is addressed as Serial2 and Serial2.begin(11520); works.
I am sure you get the idea and can address the other ports right up to Serial8.begin(11520);.
 
mgaert said:
I don’t see where pins are set for RX/TX and here are 8 potential RX/TX sets. What am I missing?
Click to expand...

Every Teensy comes with a pinout reference card that shows which pins. I'm guessing you already have that? Or you can see it on the Teensy 4.1 page and find a link to download the PDF.

If you're looking for more detailed documentation, this page has all the details.

Teensyduino: Using the UART (real serial) with Teensy on the Arduino IDE

www.pjrc.com www.pjrc.com

If your words "where pins are set for RX/TX" are asking about the low-level technical details, you'll need to read the reference manual and maybe HardwareSerial code in the core library. Ultimately the 8 hardware serial ports inside the chip are connected to specific signal muxes on certain pins. So a combination of which serial port is used and how those pin muxes are configured are the technical details of which pins do what. But much like not needing to rebuild an engine simply to drive a car, most people just use Serial1 to Serial8 in their programs and connect to the documented pins and it just works.
 
MichaelMC said:
Hello Micky,
You mentioned you picked up a Teensy 4.1 for this, so here is fine.

The C4 connects to the Teensy via the Teensy's USB host port, with this cable and as seen here : https://www.pjrc.com/store/cable_usb_host_t36.html
Grab that cable, power up the C4, power up the Teensy (I use a custom 5v USB power pack). You're now ready to upload the demo .ino.
Click to expand...
Great thanks. I did buy that cable along with the Teensy so I just need to do a teensy bit of research to double check where the connections to the board go. Mr. Stoffregen has provided that page below.

I'm using VSCode so I had to turn the .ino into 'main.cpp' but really no big, just had to move the functions around.

BTW I did complete a prototype Host USB MIDI controller for the C4 using that 'other board' ...
 
PaulStoffregen said:
Every Teensy comes with a pinout reference card that shows which pins. I'm guessing you already have that? Or you can see it on the Teensy 4.1 page and find a link to download the PDF.

If you're looking for more detailed documentation, this page has all the details.

Teensyduino: Using the UART (real serial) with Teensy on the Arduino IDE

www.pjrc.com www.pjrc.com

If your words "where pins are set for RX/TX" are asking about the low-level technical details, you'll need to read the reference manual and maybe HardwareSerial code in the core library. Ultimately the 8 hardware serial ports inside the chip are connected to specific signal muxes on certain pins. So a combination of which serial port is used and how those pin muxes are configured are the technical details of which pins do what. But much like not needing to rebuild an engine simply to drive a car, most people just use Serial1 to Serial8 in their programs and connect to the documented pins and it just works.
Click to expand...
Wordz is hard.

Got the board, got the cable, got the beautiful pin out card. I am absolutely not asking about low-level details Gaia forbid. I was used to that 'other board' where I had to connect a USB host board to RX/TX. I've only started with the Teensy but I now see some very nice coppery holes where I can solder some pins.

Thanks!
 
Finally, a video!
Here is the Delay/Tuner pedal, using the builtin Audio library along, with this C4Synth library:
 
mgaert said:
Wordz is hard.

Got the board, got the cable, got the beautiful pin out card. I am absolutely not asking about low-level details Gaia forbid. I was used to that 'other board' where I had to connect a USB host board to RX/TX. I've only started with the Teensy but I now see some very nice coppery holes where I can solder some pins.

Thanks!
Click to expand...
BTW, I got everything going with the C4, thanks!
 
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