Drum Rack example

firmware/README.md

@@ -16,6 +16,7 @@ Custom micropython build for the Olimex RP2350B-XL. Comes with some features ena
 9. Run `make BOARD=OLIMEX_PICO2_XL submodules` to install dependencies
 10. Run `make BOARD=OLIMEX_PICO2_XL clean` to remove previous build artefacts (if any)
 11. Run `make BOARD=OLIMEX_PICO2_XL` to build the firmware
+12. To rebuild: `make BOARD=OLIMEX_PICO2_XL clean && make BOARD=OLIMEX_PICO2_XL`
 
 ## flashing
 

firmware/examples/nanogrid-drum-rack/README.md

@@ -0,0 +1,20 @@
+# MIDI Drum Rack example
+
+Press to send a MIDI note in the range from C1 to D#2. Buttons are
+ordered in the same way the pads are in Ableton Drum Rack: with the USB
+port poiting from the player left-to-right, bottom-to-top.
+
+
+## build
+
+1. Make a micropython build with the libraries added:
+
+```bash
+cd $MICROPYTHON_PATH/ports/rp2
+make BOARD=OLIMEX_PICO2_XL clean && make V=1 BOARD=OLIMEX_PICO2_XL FROZEN_MANIFEST={path-to-neogrid-project}/firmware/examples/nanogrid-drum-rack/manifest.py
+```
+
+2. Flush the board with the resulting uf2 (see
+   [firmware/README.md](/firmware/README.md))
+
+3. Copy the `main.py` to the board

firmware/examples/nanogrid-drum-rack/main.py

@@ -0,0 +1,210 @@
+# MicroPython USB MIDI example
+#
+# This example demonstrates creating a custom MIDI device.
+#
+# To run this example:
+#
+# 1. Make sure `usb-device-midi` is installed via: mpremote mip install usb-device-midi
+#
+# 2. Run the example via: mpremote run midi_example.py
+#
+# 3. mpremote will exit with an error after the previous step, because when the
+#    example runs the existing USB device disconnects and then re-enumerates with
+#    the MIDI interface present. At this point, the example is running.
+#
+# 4. To see output from the example, re-connect: mpremote connect PORTNAME
+#
+#
+# MIT license; Copyright (c) 2023-2024 Angus Gratton
+import usb.device
+from usb.device.midi import MIDIInterface
+import time
+
+from machine import Pin
+
+import array, time
+import rp2
+
+NUM_COL = 4
+NUM_ROW = 4
+NUM_LEDS = NUM_COL * NUM_ROW
+PIN_NUM = 16
+brightness = 0.2
+
+@rp2.asm_pio(sideset_init=rp2.PIO.OUT_LOW, out_shiftdir=rp2.PIO.SHIFT_LEFT, autopull=True, pull_thresh=24)
+def ws2812():
+    T1 = 2
+    T2 = 5
+    T3 = 3
+    wrap_target()
+    label("bitloop")
+    out(x, 1)               .side(1)    [T3 - 1]
+    jmp(not_x, "do_zero")   .side(0)    [T1 - 1]
+    jmp("bitloop")          .side(0)    [T2 - 1]
+    label("do_zero")
+    nop()                   .side(1)    [T2 - 1]
+    wrap()
+
+def init_leds():
+    # Create the StateMachine with the ws2812 program, outputting on pin
+    sm = rp2.StateMachine(0, ws2812, freq=8_000_000, sideset_base=Pin(PIN_NUM))
+
+    # Start the StateMachine, it will wait for data on its FIFO.
+    sm.active(1)
+
+    # Display a pattern on the LEDs via an array of LED RGB values.
+    ar = array.array("I", [0 for _ in range(NUM_LEDS)])
+
+    ##########################################################################
+    def show_all():
+        dimmer_ar = array.array("I", [0 for _ in range(NUM_LEDS)])
+        for i, c in enumerate(ar):
+            r = int(((c >> 8) & 0xFF) * brightness)
+            g = int(((c >> 16) & 0xFF) * brightness)
+            b = int((c & 0xFF) * brightness)
+            dimmer_ar[i] = (g<<16) + (r<<8) + b
+        sm.put(dimmer_ar, 8)
+
+    def set_led(i, color):
+        row = i // NUM_COL
+        col = i - row * NUM_COL
+        new_col = NUM_COL - col - 1
+        new_row =  NUM_ROW - row - 1 if new_col % 2 == 0 else row
+        ar[new_col * NUM_ROW + new_row] = (color[1]<<16) + (color[0]<<8) + color[2]
+
+    return (set_led, show_all)
+
+class MIDIExample(MIDIInterface):
+    # Very simple example event handler functions, showing how to receive note
+    # and control change messages sent from the host to the device.
+    #
+    # If you need to send MIDI data to the host, then it's fine to instantiate
+    # MIDIInterface class directly.
+
+    def on_open(self):
+        super().on_open()
+        print("Device opened by host")
+
+    def on_note_on(self, channel, pitch, vel):
+        print(f"RX Note On channel {channel} pitch {pitch} velocity {vel}")
+
+    def on_note_off(self, channel, pitch, vel):
+        print(f"RX Note Off channel {channel} pitch {pitch} velocity {vel}")
+
+    def on_control_change(self, channel, controller, value):
+        print(f"RX Control channel {channel} controller {controller} value {value}")
+
+
+m = MIDIExample()
+# Remove builtin_driver=True if you don't want the MicroPython serial REPL available.
+usb.device.get().init(m, builtin_driver=True)
+
+print("Waiting for USB host to configure the interface...")
+
+while not m.is_open():
+    time.sleep_ms(100)
+
+# TX constants
+CHANNEL = 0
+PITCH_C1 = 37
+CONTROLLER = 64
+
+control_val = 0
+
+def init_btns():
+    row_pins = [
+        Pin(0, Pin.OUT),
+        Pin(1, Pin.OUT),
+        Pin(2, Pin.OUT),
+        Pin(3, Pin.OUT),
+    ]
+
+    col_pins = [
+        Pin(32, Pin.IN, Pin.PULL_UP),
+        Pin(33, Pin.IN, Pin.PULL_UP),
+        Pin(34, Pin.IN, Pin.PULL_UP),
+        Pin(35, Pin.IN, Pin.PULL_UP),
+    ]
+
+    pressed_keys = set()
+
+    # reset cols
+    for pin in row_pins:
+        pin.value(1)
+
+    def loop():
+        pressed_keys.clear()
+        for row, row_pin in enumerate(row_pins):
+            # set only active pin low, keep rest high
+            row_pin.value(0)
+            for col, col_pin in enumerate(col_pins):
+                key = (
+                    (NUM_ROW - row - 1) +
+                    (NUM_COL - col - 1) * NUM_ROW
+                )
+                if not col_pin.value():
+                    pressed_keys.add(key)
+            row_pin.value(1)
+        return set(pressed_keys)
+
+    return loop
+
+btn_loop = init_btns()
+turned_on = set()
+
+(set_led, show_all) = init_leds()
+
+# for i in range(NUM_LEDS):
+#     set_led(i, CYAN)
+#     for j in range(NUM_LEDS):
+#         if i != j:
+#             set_led(j, BLACK)
+#     show_all()
+#     time.sleep(2)
+# 
+
+CYAN = (0, 255, 255)
+BLACK = (0, 0, 0)
+
+print("Starting loop...")
+while m.is_open():
+    time.sleep_ms(5)
+    # print(f"TX Note On channel {CHANNEL} pitch {PITCH_C1}")
+    # m.note_on(CHANNEL, PITCH_C1)  # Velocity is an optional third argument
+    # time.sleep(0.5)
+    # print(f"TX Note Off channel {CHANNEL} pitch {PITCH_C1}")
+    # m.note_off(CHANNEL, PITCH_C1)
+    # time.sleep(1)
+    # print(f"TX Control channel {CHANNEL} controller {CONTROLLER} value {control_val}")
+    # m.control_change(CHANNEL, CONTROLLER, control_val)
+    # control_val += 1
+    # if control_val == 0x7F:
+    #     control_val = 0
+    # time.sleep(1)
+
+    pressed = btn_loop()
+
+    to_turn_on = pressed.difference(turned_on)
+    to_turn_off = turned_on.difference(pressed)
+
+    if len(to_turn_on):
+        print("to_turn_on", to_turn_on)
+
+    if len(to_turn_off):
+        print("to_turn_off", to_turn_off)
+
+
+    for key in to_turn_on:
+        m.note_on(CHANNEL, PITCH_C1 + key - 1)
+        set_led(key, CYAN)
+        turned_on.add(key)
+
+    for key in to_turn_off:
+        m.note_off(CHANNEL, PITCH_C1 + key - 1)
+        turned_on.remove(key)
+        set_led(key, BLACK)
+
+    show_all()
+
+print("USB host has reset device, example done.")
+

firmware/examples/nanogrid-drum-rack/manifest.py

@@ -0,0 +1,4 @@
+metadata(version="0.1.0")
+include("$(PORT_DIR)/boards/manifest.py")
+require("usb-device")
+require("usb-device-midi")