working for now

README.md

@@ -0,0 +1,37 @@
+MidiStepper
+===========
+
+Made for an old (AnyCubic) Trigorilla-Board from an 3D-Printer.
+Also compatible with Arduino Nano and old floppy drives.
+
+Floppy pins:
+------------
+
+          .....j..DS.......
+    ..G5  . ...j..GG.......
+
+    j: jumper (drive select)
+    D: direction
+    S: step
+    G: corresponding ground
+    5: 5V for the motors
+
+Caveats:
+--------
+The ATmega2560 has 6 timers, so we can use them to generate the square waves for the steps. Be aware that delay() and similar arduino-functions will not work as expected if you extend this and use Timer0. RAMPS14-compatible boards have only 5 stepper drivers, so we're fine.
+Other arduinos don't have enough timer peripherals, so we generate them in software. This could be done in an ISR. See: https://www.youtube.com/watch?v=fHAO7SW-SZI
+
+Usage:
+------
+
+The arduino part accepts raw midi messages over its serial interface. baudrate is 115200.
+Use the python script send.py to send midi files over the serial port. It can also act as a virtual midi port.
+
+Compile:
+--------
+    $ git clone
+    $ virtualenv -p python --no-site-packages .
+    $ source bin/activate
+    $ pip install -U platformio
+    $ pio run
+    $ pio run -t upload

platformio.ini

@@ -10,10 +10,12 @@
 
 [platformio]
 default_envs = megaatmega2560
+#default_envs = nano
 
 [common]
 lib_deps =
   ToneLibrary
+#  TimerOne
 #  AccelStepper
 #  SpeedyStepper
   MIDI Library
@@ -30,3 +32,9 @@ platform          = atmelavr
 board             = megaatmega2560
 board_build.f_cpu = 16000000L
 lib_deps          = ${common.lib_deps}
+
+[env:nano]
+platform          = atmelavr
+board             = nanoatmega328
+board_build.f_cpu = 16000000L
+lib_deps          = ${common.lib_deps}

send.py

@@ -4,7 +4,7 @@ import sys, argparse
 import time
 import threading
 
-from mido import MidiFile
+import mido
 import serial
 
 drum_channels = [9]
@@ -23,16 +23,22 @@ def main(argv):
   inputfile = ''
   outputport = ''
   parser = argparse.ArgumentParser()
-  parser.add_argument('midifilename', help="the midi file you want to send")
+  parser.add_argument('midifilename', help="the midi file you want to send. Set 'ALSA' for virtual midi port, see 'aconnect -o'")
   parser.add_argument('-P', '--serialport', help="serial port to open", default="/dev/ttyUSB0")
   parser.add_argument('--with-drums', action="store_true", help="send percussion track 10")
+  parser.add_argument('--delay', help="add delay before startup", type=int, default=1)
   args = parser.parse_args()
   with serial.Serial(args.serialport, 115200, timeout=12) as ser:
     receivethread = threading.Thread(target=serialreceive, args=(ser,))
     receivethread.daemon = True
     receivethread.start()
-    time.sleep(1)
+    time.sleep(args.delay)
-    with MidiFile(args.midifilename) as mid:
+    if args.midifilename == 'ALSA':
+#      portmidi = mido.Backend('mido.backends.portmidi')
+      midi_in = mido.open_input()
+    else:
+      midi_in = mido.MidiFile(args.midifilename)
+    with midi_in as mid:
       for msg in mid:
         time.sleep(msg.time)
         if not msg.is_meta:

src/main.cpp

@@ -5,9 +5,26 @@
  */
 
 #include <Arduino.h>
+#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
 #include "pins/pins_TRIGORILLA_14.h"
-
+#elif defined(__AVR_ATmega328P__)
-#include <Tone.h>
+#define LED_PIN LED_BUILTIN
+#define X_DIR_PIN PD2
+#define X_STEP_PIN PD3
+#define X_ENABLE_PIN A0
+#define Y_DIR_PIN PD4
+#define Y_STEP_PIN PD5
+#define Y_ENABLE_PIN A1
+#define Z_DIR_PIN PD6
+#define Z_STEP_PIN PD7
+#define Z_ENABLE_PIN A2
+#define E0_DIR_PIN PB0
+#define E0_STEP_PIN PB1
+#define E0_ENABLE_PIN A3
+#define E1_DIR_PIN PB2
+#define E1_STEP_PIN PB3
+#define E1_ENABLE_PIN A4
+#endif
 
 #include <MIDI.h>
 //#include "midi/noteList.h"
@@ -24,7 +41,11 @@ MIDI_CREATE_CUSTOM_INSTANCE(HardwareSerial, Serial, MIDI, MySettings);
 
 const int NUM_STEPPER = 5;
 
+#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
 TimerStepper stepper[NUM_STEPPER];
+#elif defined(__AVR_ATmega328P__)
+LoopStepper stepper[NUM_STEPPER];
+#endif
 
 unsigned long previousMillis[NUM_STEPPER] = {0};        // will store last time LED was updated
 const long interval = 1000;           // interval at which to blink (milliseconds)
@@ -140,6 +161,19 @@ void setup()
   stepper[3].begin(E0_DIR_PIN, E0_STEP_PIN, E0_ENABLE_PIN);
   stepper[4].begin(E1_DIR_PIN, E1_STEP_PIN, E1_ENABLE_PIN);
 
+
+  for (int i = 0; i < NUM_STEPPER; i++) {
+#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
+    stepper[i].setMaxFrequency(12000);
+#elif defined(__AVR_ATmega328P__)
+    stepper[i].setMaxFrequency(1400);
+    Serial.print("homing stepper ");
+    Serial.println(i);
+    stepper[i].setMaxPosition(80);
+#endif
+  }
+
+
   MIDI.setHandleNoteOn(handleNoteOn);
   MIDI.setHandleNoteOff(handleNoteOff);
   MIDI.setHandlePitchBend(handlePitchBend);

src/stepper.h

@@ -3,6 +3,7 @@
 
 #include <Arduino.h>
 #include <Tone.h>
+//#include <TimerOne.h>
 
 class FrequencyLUT {
   public:
@@ -12,7 +13,11 @@ class FrequencyLUT {
 };
 
 FrequencyLUT::FrequencyLUT() {
+#if defined(__AVR_ATmega1280__) || defined(__AVR_ATmega2560__)
   int pitch = 24;
+#elif defined(__AVR_ATmega328P__)
+  int pitch = 0;
+#endif
   frequencies = malloc(128*sizeof(uint16_t));
   for (int d=0; d<128; d++) {
     frequencies[d] = pow(2.0, (d-69.0+pitch)/12.0) * 440.0;
@@ -35,12 +40,14 @@ class Stepper {
     virtual void stopTone() = 0;
     void enable();
     void disable();
+    void setMaxFrequency(uint16_t max_freq);
   protected:
     int8_t currentNote;
     int dir_pin;
     int step_pin;
     int enable_pin;
     uint8_t multiplicator = 4;
+    uint16_t maxFrequency;
 };
 
 class TimerStepper : public Stepper {
@@ -59,8 +66,12 @@ class LoopStepper : public Stepper {
     void playTone(uint16_t freq) override;
     void stopTone() override;
     void loop() override;
+    void setMaxPosition(int pos);
   private:
-    unsigned long currentStepMicros;
+    unsigned long currentStepMicros = 0;
+    unsigned long currentPosition;
+    unsigned long maxPosition;
+    bool direction;
     unsigned long prevStepMicros;
 };
 
@@ -81,6 +92,7 @@ void Stepper::enable() {
 }
 
 void Stepper::disable() {
+  stopTone();
   digitalWrite(enable_pin, HIGH);
 }
 
@@ -88,7 +100,7 @@ void Stepper::playNote(int8_t midi_note) {
   currentNote = midi_note;
   uint16_t f = frequencies[midi_note];
   f *= multiplicator;
-  while (f > 12000) f/=2;
+  while (f > maxFrequency) f/=2;
   playTone(f);
 }
 
@@ -98,6 +110,10 @@ void Stepper::bend(int value) {
   playTone(f_b);
 }
 
+void Stepper::setMaxFrequency(uint16_t max_freq) {
+  maxFrequency = max_freq;
+}
+
 void TimerStepper::begin(int dir_pin, int step_pin, int enable_pin) {
   Stepper::begin(dir_pin, step_pin, enable_pin);
   tone.begin(step_pin);
@@ -128,15 +144,34 @@ void LoopStepper::stopTone() {
   currentStepMicros = 0;
 }
 
+void LoopStepper::setMaxPosition(int pos) {
+  maxPosition = 2*pos;
+  currentPosition = 2*pos;
+  currentStepMicros = 4545UL;
+  direction = 1;
+  prevStepMicros = micros();
+  while (currentPosition > 0) loop();
+  while (currentPosition != 2) loop();
+  currentPosition = 0; maxPosition -=4;
+  direction = 0;
+  currentStepMicros = 0;
+}
+
 void LoopStepper::loop() {
   if (currentStepMicros == 0) return;
+
   if (micros() - prevStepMicros >= currentStepMicros) {
     prevStepMicros += currentStepMicros;
-    digitalWrite(step_pin, HIGH);
+    digitalWrite(step_pin, !digitalRead(step_pin));
-    digitalWrite(step_pin, LOW);
+//    digitalWrite(step_pin, HIGH);
+//    digitalWrite(step_pin, LOW);
+    if (direction == 0) currentPosition++;
+    else currentPosition--;
+    if (currentPosition >= maxPosition) direction = 1;
+    if (currentPosition <= 0) direction = 0;
+    digitalWrite(dir_pin, direction);
   }
 }
 
 
-
 #endif /* _STEPPER_H */