# VARASYS PolyMeter — PM_K-1 "Kit" firmware (CircuitPython edition) # Raspberry Pi Pico (Pico / Pico W / Pico 2) on the 52Pi EP-0172 "Pico Breadboard Kit Plus": # 3.5" ST7796 320x480 cap-touch (GT911), PSP joystick, WS2812 RGB, buzzer, 2 buttons. # # WHY CIRCUITPYTHON: the board then mounts as a USB drive (CIRCUITPY) carrying this code, your # tracks (programs.json) and a copy of the editor — edit on the web, "Save to device" writes # programs.json here, and CircuitPython auto-reloads with the new grooves. (USB-MIDI audio out # to the computer comes in a later phase.) Runs the SAME program strings as metronome.varasys.io. # # INSTALL: flash CircuitPython (https://circuitpython.org/board/raspberry_pi_pico/), then copy # this file as code.py plus programs.json onto the CIRCUITPY drive. It runs on boot. # # Fallback: the simpler MicroPython firmware (pico/main.py) is always available — BOOTSEL + # drag a MicroPython .uf2 to go back. The Pico cannot be bricked. # # Untested-panel notes & calibration flags are in CONFIG + pico-cp/README.md. import board, busio, digitalio, analogio, pwmio, displayio, vectorio, time, json, gc try: # CircuitPython 9.x from fourwire import FourWire from busdisplay import BusDisplay except ImportError: # CircuitPython 8.x from displayio import FourWire from displayio import Display as BusDisplay try: import neopixel_write # core module on RP2040 — drives WS2812 with no external library except ImportError: neopixel_write = None # ============================== CONFIG (tweak if needed) ============================== SPI_BAUD = 40_000_000 WIDTH, HEIGHT = 320, 480 MADCTL = 0x48 # portrait; 0x48 swaps R/B for this BGR panel (cyan reads cyan). Use 0x40 if reversed. INVERT_COLORS = True # most ST7796 modules need inversion ON; set False if colours look negative # Touch (GT911) — flip if taps land wrong: TOUCH_SWAP_XY = False TOUCH_INVERT_X = False TOUCH_INVERT_Y = False TOUCH_DEBUG = False # Joystick: JOY_INVERT_X = False JOY_INVERT_Y = False JOY_DEADZONE = 9000 # ----- pins (fixed by the EP-0172 board) ----- P_SCK, P_MOSI, P_CS, P_DC, P_RST = board.GP2, board.GP3, board.GP5, board.GP6, board.GP7 P_SDA, P_SCL = board.GP8, board.GP9 P_RGB, P_BUZ, P_BTNA, P_BTNB = board.GP12, board.GP13, board.GP15, board.GP14 P_JOYX, P_JOYY = board.GP26, board.GP27 # ----- baked default grooves (used only if programs.json is missing/bad) ----- DEFAULT_PROGRAMS = [ ("Four on the floor", "t120;kick:4;snare:4=.x.x;hatClosed:4/2"), ("Swing ride", "t150;ride:4/2s;kick:4=X..x;snare:4=.x.x"), ("7/8 (2+2+3)", "t130;kick:2+2+3=x..x..x;hatClosed:2+2+3/2"), ("5 over 4", "t100;kick:4;claves:5~"), ("Straight click", "t120;beep:4"), ] # ============================== COLOURS (0xRRGGBB; displayio handles 565) ============================== C_BG, C_PANEL, C_TXT, C_MUTE = 0x06090E, 0x1C222C, 0xC7D0DB, 0x788494 C_CYAN, C_AMBER, C_GREEN, C_DIM = 0x0AB3F7, 0xFF9B2E, 0x2FE07A, 0x243240 C_BTN = 0x1C222C LEVEL_RGB = {2: (255, 110, 0), 1: (0, 150, 255), 3: (130, 70, 255)} MAXLANES = 5 # lanes shown on the pad grid (extras still play) PAD_DIM = (0x10161E, 0x0A3A52, 0x4A3010, 0x2A1D4A) # idle pad: mute / normal / accent / ghost PAD_LIT = (0x39414D, 0x0AB3F7, 0xFF9B2E, 0x967BFF) # playhead pad: mute / normal / accent / ghost # WS2812 RGB LED — self-contained via the core neopixel_write module (no external library) class RGB: def __init__(self, pin): self.ok = neopixel_write is not None if self.ok: self.io = digitalio.DigitalInOut(pin); self.io.direction = digitalio.Direction.OUTPUT self.buf = bytearray(3) def set(self, r, g, b): if not self.ok: return self.buf[0] = g; self.buf[1] = r; self.buf[2] = b # WS2812 wants GRB order try: neopixel_write.neopixel_write(self.io, self.buf) except Exception: self.ok = False # ============================== ANTI-ALIASED FONTS (binary blobs on the drive; see pico/gen_font.py) ============================== def load_font(path): with open(path, "rb") as f: blob = f.read() count = blob[0]; p = 1; pixoff = 1 + count * 7; glyphs = {} for _ in range(count): cp = (blob[p] << 8) | blob[p+1]; w = blob[p+2]; h = blob[p+3] xoff = blob[p+4]; xoff = xoff - 256 if xoff > 127 else xoff top = blob[p+5]; adv = blob[p+6]; p += 7 glyphs[cp] = (w, h, xoff, top, adv, pixoff); pixoff += (w * h + 1) // 2 return (glyphs, blob) FONT_M = load_font("/font_m.bin") FONT_L = load_font("/font_l.bin") gc.collect() def _blend(bg, fg, i): t = i * 17 r = (((bg >> 16) & 0xFF)*(255-t) + ((fg >> 16) & 0xFF)*t) // 255 g = (((bg >> 8) & 0xFF)*(255-t) + ((fg >> 8) & 0xFF)*t) // 255 b = ((bg & 0xFF)*(255-t) + (fg & 0xFF)*t) // 255 return (r << 16) | (g << 8) | b def make_text(s, font, fg, bg): """Render a string into a displayio TileGrid (anti-aliased via a 16-step blend palette).""" glyphs, blob = font w = 0; top0 = 999; bot = 0 for c in s: g = glyphs.get(ord(c)) if not g: continue w += g[4] if g[1]: if g[3] < top0: top0 = g[3] if g[3] + g[1] > bot: bot = g[3] + g[1] if top0 == 999: top0 = 0 w = max(1, w); h = max(1, bot - top0) gc.collect() bmp = displayio.Bitmap(w, h, 16) pal = displayio.Palette(16) for i in range(16): pal[i] = _blend(bg, fg, i) pen = 0 for c in s: g = glyphs.get(ord(c)) if not g: continue gw, gh, xoff, gtop, adv, off = g for j in range(gh): row = (gtop - top0) + j for i in range(gw): k = j * gw + i byte = blob[off + (k >> 1)] nib = (byte >> 4) if (k & 1) == 0 else (byte & 0xF) if nib: x = pen + xoff + i if 0 <= x < w and 0 <= row < h: bmp[x, row] = nib pen += adv return displayio.TileGrid(bmp, pixel_shader=pal), w, h # ============================== POLYMETER ENGINE (same semantics as the web/MicroPython) ============================== PAT = {'X': 2, 'x': 1, 'g': 3, '.': 0, '-': 0, '_': 0} PRIO = {2: 3, 1: 2, 3: 1} def parse_program(s): bpm = 120; lanes = [] for tok in s.strip().split(';'): tok = tok.strip() if not tok: continue if tok[0] == 't' and tok[1:].isdigit(): bpm = int(tok[1:]); continue if ':' not in tok: continue lane = _parse_lane(tok) if lane: lanes.append(lane) if not lanes: lanes = [_parse_lane("beep:4")] return max(30, min(300, bpm)), lanes def _parse_lane(tok): poly = '~' in tok; mute = '!' in tok tok = tok.replace('~', '').replace('!', '') if '@' in tok: tok = tok.split('@')[0] sound, _, rest = tok.partition(':') pattern = None if '=' in rest: rest, _, pattern = rest.partition('=') sub = 1 if '/' in rest: rest, _, sd = rest.partition('/'); sd = sd.rstrip('s') sub = int(sd) if sd.isdigit() else 1 groups = [int(g) for g in rest.split('+') if g.isdigit()] or [4] beats = sum(groups); starts = set(); acc = 0 for gp in groups: starts.add(acc); acc += gp steps = beats * sub if pattern: levels = [PAT.get(ch, 0) for ch in pattern] if len(levels) < steps: levels += [0] * (steps - len(levels)) steps = len(levels) else: levels = [] for i in range(steps): if i % sub == 0: levels.append(2 if (i // sub) in starts else 1) else: levels.append(0) return {'sound': sound, 'sub': sub, 'steps': steps, 'levels': levels, 'poly': poly, 'mute': mute} def load_programs(): try: with open("/programs.json") as f: d = json.load(f) progs = [(p["name"], p["prog"]) for p in d["programs"]] if progs: return progs except Exception as e: print("programs.json:", e) return DEFAULT_PROGRAMS # ============================== GT911 TOUCH ============================== class GT911: def __init__(self, i2c): self.i2c = i2c; self.addr = None while not i2c.try_lock(): pass try: found = i2c.scan() finally: i2c.unlock() for a in (0x5D, 0x14): if a in found: self.addr = a; break if self.addr is None and found: self.addr = found[0] def _rd(self, reg, n): b = bytearray(n) while not self.i2c.try_lock(): pass try: self.i2c.writeto(self.addr, bytes([reg >> 8, reg & 0xFF])) self.i2c.readfrom_into(self.addr, b) finally: self.i2c.unlock() return b def _wr(self, reg, val): while not self.i2c.try_lock(): pass try: self.i2c.writeto(self.addr, bytes([reg >> 8, reg & 0xFF, val])) finally: self.i2c.unlock() def read(self): if self.addr is None: return None try: st = self._rd(0x814E, 1)[0] except OSError: return None if not (st & 0x80): return None n = st & 0x0F; pt = None if n >= 1: b = self._rd(0x8150, 4); tx = b[0] | (b[1] << 8); ty = b[2] | (b[3] << 8) pt = self._map(tx, ty) try: self._wr(0x814E, 0) except OSError: pass return pt def _map(self, tx, ty): if TOUCH_DEBUG: print("touch raw", tx, ty) if TOUCH_SWAP_XY: tx, ty = ty, tx if TOUCH_INVERT_X: tx = WIDTH - 1 - tx if TOUCH_INVERT_Y: ty = HEIGHT - 1 - ty if 0 <= tx < WIDTH and 0 <= ty < HEIGHT: return (tx, ty) return None # ============================== DISPLAY SETUP ============================== def st7796_init(): inv = b'\x21\x00' if INVERT_COLORS else b'\x20\x00' return ( b'\x01\x80\x78' # SWRESET + 120ms b'\x11\x80\x78' # SLPOUT + 120ms b'\xF0\x01\xC3' b'\xF0\x01\x96' # command-set unlock + bytes([0x36, 0x01, MADCTL]) + b'\x3A\x01\x55' # 16bpp b'\xB4\x01\x01' b'\xB6\x03\x80\x02\x3B' b'\xE8\x08\x40\x8A\x00\x00\x29\x19\xA5\x33' b'\xC1\x01\x06' b'\xC2\x01\xA7' b'\xC5\x81\x18\x78' # VCOM + 120ms b'\xE0\x0E\xF0\x09\x0B\x06\x04\x15\x2F\x54\x42\x3C\x17\x14\x18\x1B' b'\xE1\x0E\xE0\x09\x0B\x06\x04\x03\x2B\x43\x42\x3B\x16\x14\x17\x1B' b'\xF0\x01\x3C' b'\xF0\x81\x69\x78' # lock + 120ms + inv + b'\x29\x80\x32' # DISPON + 50ms ) def make_display(): displayio.release_displays() spi = busio.SPI(clock=P_SCK, MOSI=P_MOSI) bus = FourWire(spi, command=P_DC, chip_select=P_CS, reset=P_RST, baudrate=SPI_BAUD) return BusDisplay(bus, st7796_init(), width=WIDTH, height=HEIGHT, auto_refresh=False) def solid(color): p = displayio.Palette(1); p[0] = color; return p def rect(x, y, w, h, color): return vectorio.Rectangle(pixel_shader=solid(color), width=w, height=h, x=x, y=y) # ============================== APP ============================== class App: def __init__(self): self.display = make_display() self.i2c = busio.I2C(scl=P_SCL, sda=P_SDA, frequency=400_000) self.touch = GT911(self.i2c) self.led = RGB(P_RGB) self.buz = pwmio.PWMOut(P_BUZ, frequency=1600, variable_frequency=True, duty_cycle=0) self.buz_off = 0 self.btnA = self._btn(P_BTNA); self.btnB = self._btn(P_BTNB) self._aPrev = True; self._bPrev = True self.jx = analogio.AnalogIn(P_JOYX); self.jy = analogio.AnalogIn(P_JOYY) self._joyNext = 0 self._touchDown = False; self._touchSeen = 0 self.running = False; self.bpm = 120; self.idx = 0; self.lanes = []; self.rgb = (0, 0, 0) self.programs = load_programs() self.buttons = [] self.dirty = True self.pad_pal = displayio.Palette(8) for i in range(4): self.pad_pal[i] = PAD_DIM[i]; self.pad_pal[i + 4] = PAD_LIT[i] self.lane_pads = []; self.lane_lit = [] self._build_scene() self.load(0) def _btn(self, pin): d = digitalio.DigitalInOut(pin); d.direction = digitalio.Direction.INPUT; d.pull = digitalio.Pull.UP return d # ---------- scene graph ---------- def _build_scene(self): root = displayio.Group(); self.display.root_group = root root.append(rect(0, 0, WIDTH, HEIGHT, C_BG)) tg, w, h = make_text("PM_K-1 KIT", FONT_M, C_CYAN, C_BG); tg.x = 12; tg.y = 8; root.append(tg) root.append(rect(0, 38, WIDTH, 2, C_PANEL)) # dynamic groups self.g_bpm = displayio.Group(); root.append(self.g_bpm) # big tempo (right) self.g_run = displayio.Group(); root.append(self.g_run) # RUN / STOP (left) self.g_name = displayio.Group(); root.append(self.g_name) # item index + name self.g_grid = displayio.Group(); root.append(self.g_grid) # lanes × step pads # buttons (rects static; labels in per-button groups so play can toggle) bw, bh = 96, 56; gap = (WIDTH - 3*bw)//4; xs = [gap, gap*2+bw, gap*3+bw*2] self.btn_lbl = {} rows = [(300, ("prev", "play", "next")), (372, ("minus", "tap", "plus"))] for y, keys in rows: for x, key in zip(xs, keys): root.append(rect(x, y, bw, bh, C_BTN)) root.append(rect(x, y, bw, 2, C_PANEL)); root.append(rect(x, y+bh-2, bw, 2, C_PANEL)) lg = displayio.Group(); root.append(lg); self.btn_lbl[key] = (lg, x+bw//2, y+bh//2) self.buttons.append((x, y, bw, bh, key)) self._label(key) def _place(self, group, s, x, y, fg, bg, font, right_edge=None): while len(group): group.pop() self.dirty = True if not s: return tg, w, h = make_text(s, font, fg, bg) tg.x = (right_edge - w) if right_edge is not None else x; tg.y = y; group.append(tg) def _center(self, group, s, cx, cy, fg, bg, font): while len(group): group.pop() tg, w, h = make_text(s, font, fg, bg); tg.x = cx - w//2; tg.y = cy - h//2; group.append(tg) self.dirty = True def _label(self, key): sym = {"prev": "◀◀", "next": "▶▶", "minus": "-", "plus": "+", "tap": "TAP", "play": "■" if self.running else "▶"}[key] lg, cx, cy = self.btn_lbl[key] self._center(lg, sym, cx, cy, C_GREEN if key == "play" else C_TXT, C_BTN, FONT_M) # ---------- program ---------- def load(self, i): n = len(self.programs); self.idx = i % n self.name, prog = self.programs[self.idx] self.bpm, self.lanes = parse_program(prog) self.master = self.lanes[0] self._reset_clock(); self.draw_bpm(); self.draw_status(); self.build_grid() def _reset_clock(self): now = time.monotonic_ns() for L in self.lanes: L['next'] = now; L['step'] = -1; L['dur'] = int(60_000_000_000 / self.bpm / L['sub']) # ---------- audio + light ---------- def click(self, level): self.buz.frequency = {2: 2300, 1: 1600, 3: 1050}.get(level, 1600) self.buz.duty_cycle = {2: 42000, 1: 30000, 3: 14000}.get(level, 30000) self.buz_off = time.monotonic_ns() + 22_000_000 def flash(self, level): self.rgb = LEVEL_RGB.get(level, (0, 150, 255)) self.led.set(*self.rgb) def led_off(self): self.rgb = (0, 0, 0) self.led.set(0, 0, 0) # ---------- transport ---------- def toggle(self): self.running = not self.running if self.running: self._reset_clock() else: self.buz.duty_cycle = 0; self.led_off(); self.reset_playheads() self.draw_status(); self._label("play") def set_bpm(self, v): v = max(30, min(300, v)) if v != self.bpm: self.bpm = v for L in self.lanes: L['dur'] = int(60_000_000_000 / self.bpm / L['sub']) self.draw_bpm() def goto(self, i): was = self.running; self.load(i); self._label("play") if was: self.running = True; self._reset_clock() def tap(self): now = time.monotonic() if not hasattr(self, '_taps'): self._taps = [] self._taps = [t for t in self._taps if now - t < 2.4] self._taps.append(now) if len(self._taps) >= 2: span = (self._taps[-1] - self._taps[0]) / (len(self._taps) - 1) if span > 0: self.set_bpm(round(60 / span)) # ---------- scheduler ---------- def tick(self): now = time.monotonic_ns() if self.buz_off and now >= self.buz_off: self.buz.duty_cycle = 0; self.buz_off = 0 if self.running: fired = [] for li, L in enumerate(self.lanes): adv = False while now >= L['next']: L['step'] = (L['step'] + 1) % L['steps'] lvl = 0 if L['mute'] else L['levels'][L['step']] if lvl > 0: fired.append(lvl) L['next'] += L['dur']; adv = True if adv and li < len(self.lane_pads): self._move_playhead(li, L['step']) if fired: best = max(fired, key=lambda l: PRIO.get(l, 0)); self.click(best); self.flash(best) if self.rgb != (0, 0, 0): r, g, b = self.rgb; r = r*7//10; g = g*7//10; b = b*7//10 self.rgb = (r, g, b) if (r+g+b) > 12 else (0, 0, 0) self.led.set(*self.rgb) # ---------- inputs ---------- def poll(self): a = self.btnA.value if (not a) and self._aPrev: self.toggle() self._aPrev = a b = self.btnB.value if (not b) and self._bPrev: self.tap() self._bPrev = b now = time.monotonic_ns() if now >= self._joyNext: x = self.jx.value - 32768; y = self.jy.value - 32768 if JOY_INVERT_X: x = -x if JOY_INVERT_Y: y = -y if abs(y) > JOY_DEADZONE: self.set_bpm(self.bpm + (1 if y > 0 else -1) * (5 if abs(y) > 26000 else 1)) self._joyNext = now + 70_000_000 elif abs(x) > JOY_DEADZONE: self.goto(self.idx + (1 if x > 0 else -1)); self._joyNext = now + 350_000_000; return else: self._joyNext = now + 20_000_000 pt = self.touch.read() nowms = time.monotonic() if pt: self._touchSeen = nowms if not self._touchDown: self._touchDown = True; self.hit(pt[0], pt[1]) elif self._touchDown and (nowms - self._touchSeen) > 0.14: self._touchDown = False def hit(self, x, y): for bx, by, bw, bh, key in self.buttons: if bx <= x <= bx+bw and by <= y <= by+bh: if key == 'play': self.toggle() elif key == 'prev': self.goto(self.idx - 1) elif key == 'next': self.goto(self.idx + 1) elif key == 'minus': self.set_bpm(self.bpm - 1) elif key == 'plus': self.set_bpm(self.bpm + 1) elif key == 'tap': self.tap() return # ---------- drawing ---------- def draw_bpm(self): self._place(self.g_bpm, str(self.bpm), 0, 44, C_TXT, C_BG, FONT_L, right_edge=WIDTH-12) def draw_status(self): self._place(self.g_run, "RUN" if self.running else "STOP", 12, 48, C_GREEN if self.running else C_MUTE, C_BG, FONT_M) self._place(self.g_name, "%d/%d %s" % (self.idx+1, len(self.programs), self.name[:18]), 12, 112, C_TXT, C_BG, FONT_M) # ---------- pad grid (each lane = a row of step pads; playhead lit as it plays) ---------- def _padbase(self, L, s): return 0 if L['mute'] else L['levels'][s] def build_grid(self): while len(self.g_grid): self.g_grid.pop() self.lane_pads = []; self.lane_lit = [] n = min(len(self.lanes), MAXLANES) top = 140; rowh = min(38, (294 - top) // max(1, n)) for li in range(n): L = self.lanes[li]; y = top + li * rowh tg, w, h = make_text((L.get('sound', '') or '?')[:4], FONT_M, C_MUTE, C_BG) tg.x = 10; tg.y = y + 2; self.g_grid.append(tg) steps = L['steps']; px0 = 66; pw = (WIDTH - 10 - px0) // steps; ph = max(8, rowh - 10) pads = [] for s in range(steps): r = vectorio.Rectangle(pixel_shader=self.pad_pal, width=max(2, pw - 1), height=ph, x=px0 + s*pw, y=y) r.color_index = self._padbase(L, s); self.g_grid.append(r); pads.append(r) self.lane_pads.append(pads); self.lane_lit.append(-1) self.dirty = True def _move_playhead(self, li, step): pads = self.lane_pads[li]; prev = self.lane_lit[li] if 0 <= prev < len(pads): pads[prev].color_index = self._padbase(self.lanes[li], prev) if step < len(pads): pads[step].color_index = self._padbase(self.lanes[li], step) + 4 self.lane_lit[li] = step; self.dirty = True def reset_playheads(self): for li, pads in enumerate(self.lane_pads): prev = self.lane_lit[li] if 0 <= prev < len(pads): pads[prev].color_index = self._padbase(self.lanes[li], prev) self.lane_lit[li] = -1 self.dirty = True def run(self): if self.touch.addr is None: print("GT911 touch not found") while True: self.tick(); self.poll() # push a complete frame only when something changed (no mid-update tearing); # capped at the display's refresh rate, so dirty regions stay small and quick if self.dirty and self.display.refresh(): self.dirty = False time.sleep(0.0005) App().run()