First draft

LICENSE

@@ -1,6 +1,6 @@
 MIT License
 
-Copyright (c) 2018 gdsports
+Copyright (c) 2018 [email protected]
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -1,2 +1,41 @@
-# miniuntz
-Mini Untztrument Demo, Arduino Style
+# Mini Untztrument Demo, Arduino Style
+
+miniuntz is based on the code at
+[Adafruit's Mini Untztrument tutorial](https://learn.adafruit.com/mini-untztrument-3d-printed-midi-controller)
+but miniuntz does not depend on Teensy USB code. It uses the Arduino MIDIUSB
+library by Gary Grewal which simplifies the software installation.
+
+miniuntz has been tested on the SparkFun Pro Micro 5V which has the same
+processor (32u4) as the Leonardo. The Adafruit Itsy Bitsy 5V also has a 32u4
+processor so it should also work.
+
+|Trellis  |Pro Micro|
+|-------  |---------|
+|5V       |RAW|
+|GND      |GND|
+|SDA      |2|
+|SCL      |3|
+|INT      |not connected|
+
+miniuntz has been tested on the Adafruit Trinket M0 with bidirectional logic
+level changer.  Analog inputs are not tested. But the Trinket M0 should have 3
+inputs for analog input, if desired.  This should also work with the Itsy Bitsy
+M0, Feather M0, SparkFun SAMD21, and Arduino Zero. All use 3.3V logic levels so
+a logic level converter is used.
+
+|Trellis     |LLCONV      |Trinket M0|
+|-------     |------      |----------|
+|            |     LV     |3.3|
+|5V          |HV          |USB|
+|GND         |GND-GND     |GND|
+|SCL         |HV1-LV1     |SCL|
+|SDA         |HV2-LV2     |SDA|
+|INT         |HV3-LV3     |not connected|
+
+LLCONV = bidirectional logic level converter such as Adafruit BSS138 board.
+ https://www.adafruit.com/product/757
+
+![Photo of Adafruit Trinket M0 and logic level converter](https://github.com/gdsports/miniuntz/blob/master/images/trinket_m0_trellis_a.jpg)
+![Photo of back of Adafruit trellis board](https://github.com/gdsports/miniuntz/blob/master/images/trinket_m0_trellis_b.jpg)
+![Photo of Trinket M0 and mini Untztrument](https://github.com/gdsports/miniuntz/blob/master/images/trinket_m0_trellis_c.jpg)
+

miniuntz.ino

@@ -0,0 +1,193 @@
+/****************************************************************************
+MIT License
+
+Copyright (c) 2018 [email protected]
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.
+****************************************************************************/
+
+/*
+ * Mini Untztrument Demo, Arduino Style
+ *
+ * https://learn.adafruit.com/mini-untztrument-3d-printed-midi-controller
+ *
+ * miniuntz is based on the code at the above link but it does not depend on
+ * Teensy USB code. It uses the Arduino MIDIUSB library by Gary Grewal which
+ * simplifies the software installation.
+ *
+ * WARNING: Do not enable ANALOG_INPUT unless pots are hooked up to the analog
+ * inputs. If nothing is connected, the analog inputs will pick up random noise
+ * which will result in a never ending stream of MIDI CC messages.
+ *
+ * miniuntz has been tested on the SparkFun Pro Micro 5V which has the same
+ * processor (32u4) as the Leonardo. The Adafruit Itsy Bitsy 5V also has a 32u4
+ * processor so it should also work.
+ *
+ * Trellis  Pro Micro
+ * =======  =========
+ * 5V       RAW
+ * GND      GND
+ * SDA      2
+ * SCL      3
+ * INT      not connected
+ *
+ * miniuntz has been tested on the Adafruit Trinket M0 with bidirectional logic
+ * level changer.  Analog inputs not tested. But the Trinket M0 should have 3
+ * inputs for analog input, if desired.  This should also work with the Itsy
+ * Bitsy M0, Feather M0, SparkFun SAMD21, and Arduino Zero. All use 3.3V logic
+ * levels so a logic level converter is required.
+ *
+ * Trellis     LLCONV      Trinket M0
+ * =======     ======      =======
+ *                  LV     3.3
+ * 5V          HV          USB
+ * GND         GND-GND     GND
+ * SCL         HV1-LV1     SCL
+ * SDA         HV2-LV2     SDA
+ * INT         HV3-LV3     not connected
+ *
+ * LLCONV = bidirectional logic level converter such as Adafruit BSS138 board.
+ *  https://www.adafruit.com/product/757
+ */
+
+#include <Wire.h>
+#include <Adafruit_Trellis.h>
+#include <MIDIUSB.h>
+
+#define LED     LED_BUILTIN // Pin for heartbeat LED (shows code is working)
+#define CHANNEL 1           // MIDI channel number
+
+Adafruit_Trellis trellis;
+
+/*
+ * Do not enable without connecting pots to the inputs.
+ */
+//#define ANALOG_INPUT
+
+uint8_t       heart        = 0;  // Heartbeat LED counter
+unsigned long prevReadTime = 0L; // Keypad polling timer
+#ifdef ANALOG_INPUT
+uint8_t       mod;
+uint8_t       vel;
+uint8_t       fxc;
+uint8_t       rate;
+#endif
+
+uint8_t note[] = {
+  60, 61, 62, 63,
+  56, 57, 58, 59,
+  52, 53, 54, 55,
+  48, 49, 50, 51
+};
+
+// First parameter is the event type (0x09 = note on, 0x08 = note off).
+// Second parameter is note-on/note-off, combined with the channel.
+// Channel can be anything between 0-15. Typically reported to the user as 1-16.
+// Third parameter is the note number (48 = middle C).
+// Fourth parameter is the velocity (64 = normal, 127 = fastest).
+
+void noteOn(byte channel, byte pitch, byte velocity) {
+  midiEventPacket_t noteOn = {0x09, (byte)(0x90 | channel), pitch, velocity};
+  MidiUSB.sendMIDI(noteOn);
+}
+
+void noteOff(byte channel, byte pitch, byte velocity) {
+  midiEventPacket_t noteOff = {0x08, (byte)(0x80 | channel), pitch, velocity};
+  MidiUSB.sendMIDI(noteOff);
+}
+
+// First parameter is the event type (0x0B = control change).
+// Second parameter is the event type, combined with the channel.
+// Third parameter is the control number number (0-119).
+// Fourth parameter is the control value (0-127).
+
+void controlChange(byte channel, byte control, byte value) {
+  midiEventPacket_t event = {0x0B, (byte) (0xB0 | channel), control, value};
+  MidiUSB.sendMIDI(event);
+}
+
+void setup() {
+  pinMode(LED, OUTPUT);
+  trellis.begin(0x70); // Pass I2C address
+#ifdef __AVR__
+  // Default Arduino I2C speed is 100 KHz, but the HT16K33 supports
+  // 400 KHz.  We can force this for faster read & refresh, but may
+  // break compatibility with other I2C devices...so be prepared to
+  // comment this out, or save & restore value as needed.
+  TWBR = 12;
+#endif
+  trellis.clear();
+  trellis.writeDisplay();
+#ifdef ANALOG_INPUT
+  mod = map(analogRead(0), 0, 1023, 0, 127);
+  vel = map(analogRead(1), 0, 1023, 0, 127);
+  fxc = map(analogRead(2), 0, 1023, 0, 127);
+  rate = map(analogRead(3),0, 1023, 0, 127);
+  controlChange(CHANNEL,  1, mod);
+  controlChange(CHANNEL, 11, vel);
+  controlChange(CHANNEL, 12, fxc);
+  controlChange(CHANNEL, 13, rate);
+#endif
+}
+
+void loop() {
+  unsigned long t = millis();
+  if((t - prevReadTime) >= 20L) { // 20ms = min Trellis poll time
+    if(trellis.readSwitches()) {  // Button state change?
+
+      for(uint8_t i=0; i<16; i++) { // For each button...
+        if(trellis.justPressed(i)) {
+          noteOn(CHANNEL, note[i], 127);
+
+          trellis.setLED(i);
+        } else if(trellis.justReleased(i)) {
+          noteOn(CHANNEL, note[i], 0);
+          trellis.clrLED(i);
+        }
+      }
+      trellis.writeDisplay();
+    }
+#ifdef ANALOG_INPUT
+    uint8_t newModulation = map(analogRead(0), 0, 1023, 0, 127);
+    if(mod != newModulation) {
+      mod = newModulation;
+      controlChange(CHANNEL, 1, mod);
+    }
+    uint8_t newVelocity = map(analogRead(1), 0, 1023, 0, 127);
+    if(vel != newVelocity) {
+      vel = newVelocity;
+      controlChange(CHANNEL, 11, vel);
+    }
+    uint8_t newEffect = map(analogRead(2), 0, 1023, 0, 127);
+    if(fxc != newEffect) {
+      fxc = newEffect;
+      controlChange(CHANNEL, 12, fxc);
+    }
+    uint8_t newRate = map(analogRead(3), 0, 1023, 0, 127);
+    if(rate !=newRate) {
+      rate = newRate;
+      controlChange(CHANNEL, 13, rate);
+    }
+#endif
+    prevReadTime = t;
+    digitalWrite(LED, ++heart & 32); // Blink = alive
+    MidiUSB.flush();
+  }
+  (void)MidiUSB.read(); // Discard incoming MIDI messages
+}