# The ChronoPulse: laptop side. Draws each screen and streams it to the board. # Fadi G. Haddad, HTMAA 2026. Pair with chronopulse.ino running on the board. # Built on Quentin Bolsee's computer_link example (qpad-xiao, MIT License): # https://forge.cba.mit.edu/quentin.bolsee/qpad-xiao # Needs: pip3 install numpy pyserial pillow # Run: python3 health_monitor.py import argparse import glob import math import os import time import numpy as np import serial from PIL import Image, ImageDraw, ImageFont import libs.hdlc_encoding as hdlc_encoding W, H = 128, 64 # must match the enums in the Arduino sketch FINE, CAUTION, DANGER, OFF = 0, 1, 2, 3 WAVES, LOGO = 0, 1 LABELS = {FINE: "FINE", CAUTION: "CAUTION", DANGER: "DANGER"} # how many milliseconds of heartbeat each screen pixel covers MS_PER_PX = 20 # trace placement: baseline row and how tall the spikes are, in pixels BASELINE_Y = 26 AMPLITUDE = 20 SCANLINES = True TITLE = "THE CHRONOPULSE" # title page: logo view with the lights off MENU_TITLE = "INSTRUCTIONS" # controls card: waves view with the lights off # logo throb: its width as a fraction of the screen, at rest and at the peak of a beat LOGO_REST_SCALE = 0.82 LOGO_PEAK_SCALE = 1.0 LOGO_PATH = os.path.join(os.path.dirname(os.path.abspath(__file__)), "logo", "logo_full_bw.png") # --------------------------------------------------------------------------- # Heart-monitor waves. These MUST match the same functions in the Arduino # sketch, so the trace and the lights stay in sync. t is in milliseconds. # --------------------------------------------------------------------------- def pulse(t, center, width): x = (t - center) / width return np.exp(-x * x) def fine_ecg(now): t = now % 1000 return (0.12 * pulse(t, 150, 35) - 0.15 * pulse(t, 265, 10) + 1.00 * pulse(t, 285, 12) - 0.35 * pulse(t, 305, 12) + 0.30 * pulse(t, 520, 60)) CAUTION_AT = [150, 480, 780, 1050, 1350, 1900, 2150] CAUTION_H = [0.40, 0.50, 0.45, 1.00, 0.30, 0.70, 0.35] def caution_ecg(now): t = now % 2400 v = 0.08 * np.sin(2 * math.pi * t / 400.0) for at, h in zip(CAUTION_AT, CAUTION_H): v = v + h * pulse(t, at, 14) - 0.3 * h * pulse(t, at + 22, 12) return v def danger_ecg(now): return (0.50 * np.sin(2 * math.pi * (now % 310) / 310.0) + 0.33 * np.sin(2 * math.pi * (now % 170) / 170.0 + 1.0) + 0.17 * np.sin(2 * math.pi * (now % 97) / 97.0 + 2.0)) ECG = {FINE: fine_ecg, CAUTION: caution_ecg, DANGER: danger_ecg} # --------------------------------------------------------------------------- # Drawing # --------------------------------------------------------------------------- # same as the lights: follow the upward parts of the trace; DANGER never settles def beat_wave(health, now): if health == OFF: return 0.0 v = float(ECG[health](np.float64(now))) if health == DANGER: return 0.5 + 0.5 * v return min(max(v, 0.0), 1.0) # the logo, scaled to `scale` x screen width and centered def draw_logo(source, scale): new_w = max(1, round(W * scale)) new_h = max(1, round(source.height * new_w / source.width)) logo = source.resize((new_w, new_h), Image.LANCZOS) logo = logo.point(lambda p: 255 if p > 90 else 0).convert("1") canvas = Image.new("1", (W, H), 0) canvas.paste(logo, ((W - new_w) // 2, (H - new_h) // 2)) return canvas def text_width(draw, text, font): left, _, right, _ = draw.textbbox((0, 0), text, font=font) return right - left # a lit strip across the top with the text in dark pixels, like a menu banner def draw_banner(draw, text, font): draw.rectangle((0, 0, W - 1, 11), fill=1) draw.text(((W - text_width(draw, text, font)) // 2, 0), text, font=font, fill=0) # title page: the name in plain white text, the logo filling the space below it def draw_title_page(source, font): img = Image.new("1", (W, H), 0) draw = ImageDraw.Draw(img) draw.text(((W - text_width(draw, TITLE, font)) // 2, 0), TITLE, font=font, fill=1) new_h = round(source.height * W / source.width) logo = source.resize((W, new_h), Image.LANCZOS) logo = logo.point(lambda p: 255 if p > 90 else 0).convert("1") top = 12 + (H - 12 - new_h) // 2 img.paste(logo, (0, top)) return img # a small solid arrow for a direction pad, or the pad's number def draw_symbol(draw, symbol, x, y, font): shapes = { "right": [(x, y + 2), (x, y + 10), (x + 5, y + 6)], "left": [(x + 5, y + 2), (x + 5, y + 10), (x, y + 6)], "down": [(x, y + 4), (x + 7, y + 4), (x + 3, y + 9)], "up": [(x, y + 9), (x + 7, y + 9), (x + 3, y + 4)], } if symbol in shapes: draw.polygon(shapes[symbol], fill=1) else: draw.text((x, y), symbol, font=font, fill=1) # title card shown when the lights are off: a menu banner plus the controls def draw_menu(font): img = Image.new("1", (W, H), 0) draw = ImageDraw.Draw(img) draw_banner(draw, MENU_TITLE, font) # view pads first for x, (number, label) in zip((4, 68), (("1", "WAVES"), ("2", "LOGO"))): draw.text((x, 14), number, font=font, fill=1) draw.text((x + 10, 14), label, font=font, fill=1) draw_dpad(draw, font, cx=68, cy=45) return img # a plus-shaped D-pad outline with an arrow in each arm, labeled like a controller diagram def draw_dpad(draw, font, cx, cy, arm=5, reach=15): a, L = arm, reach outline = [(cx - a, cy - L), (cx + a, cy - L), (cx + a, cy - a), (cx + L, cy - a), (cx + L, cy + a), (cx + a, cy + a), (cx + a, cy + L), (cx - a, cy + L), (cx - a, cy + a), (cx - L, cy + a), (cx - L, cy - a), (cx - a, cy - a)] draw.polygon(outline, outline=1, fill=0) draw.polygon([(cx - 3, cy - 7), (cx + 3, cy - 7), (cx, cy - 12)], fill=1) # up draw.polygon([(cx - 3, cy + 7), (cx + 3, cy + 7), (cx, cy + 12)], fill=1) # down draw.polygon([(cx - 7, cy - 3), (cx - 7, cy + 3), (cx - 12, cy)], fill=1) # left draw.polygon([(cx + 7, cy - 3), (cx + 7, cy + 3), (cx + 12, cy)], fill=1) # right draw.text((cx + a + 4, cy - L - 2), "OFF", font=font, fill=1) draw.text((cx + a + 4, cy + L - 10), "DANGER", font=font, fill=1) draw.text((cx + L + 4, cy - 6), "FINE", font=font, fill=1) draw.text((cx - L - 4 - text_width(draw, "CAUTION", font), cy - 6), "CAUTION", font=font, fill=1) def draw_waves(health, now, font): img = Image.new("1", (W, H), 0) draw = ImageDraw.Draw(img) if SCANLINES: for y in range(2, 50, 6): for x in range(0, W, 3): img.putpixel((x, y), 1) if health == OFF: return img # the right edge of the screen is "now"; older moments scroll off to the left xs = np.arange(W) times = now - (W - 1 - xs) * MS_PER_PX times = times.astype(np.float64) ys = BASELINE_Y - AMPLITUDE * ECG[health](times) ys = np.clip(ys, 0, 49) draw.line(list(zip(xs.tolist(), ys.tolist())), fill=1, width=1) draw.text((2, 52), LABELS[health], font=font, fill=1) return img def img_to_bytes(img): # same packing as demo_sine_wave.py: 1024 bytes for the 128x64 screen arr = np.array(img, dtype=bool) data = b"" for i in range(8): data += np.packbits(arr[i*8:(i+1)*8, :], axis=0, bitorder="little").tobytes() return data # how long to wait for the board's reply before assuming it's gone, in seconds REPLY_TIMEOUT_S = 2.0 RECONNECT_EVERY_S = 1.0 def parse_arguments(): parser = argparse.ArgumentParser(description="The ChronoPulse health monitor") parser.add_argument("port", type=str, nargs="?", default=None, help="Serial port (optional; found automatically if left out).") return parser.parse_args() def find_port(requested): if requested: return requested ports = sorted(glob.glob("/dev/cu.usbmodem*")) return ports[0] if ports else None # keeps trying until the board is plugged in and the port opens def connect(requested): while True: port = find_port(requested) if port: try: ser = serial.Serial(port, 250000, timeout=REPLY_TIMEOUT_S, write_timeout=REPLY_TIMEOUT_S) print(f"Connected to {port}") return ser except (serial.SerialException, OSError) as e: print(f"Can't open {port} yet ({e}); retrying...") else: print("Board not found; waiting for it to be plugged in...") time.sleep(RECONNECT_EVERY_S) def main(): args = parse_arguments() ser = connect(args.port) font = ImageFont.load_default() logo_source = Image.open(LOGO_PATH).convert("L") # start on the title page until the board reports its own state health, view, now = OFF, LOGO, 0 while True: if view == LOGO and health == OFF: img = draw_title_page(logo_source, font) elif view == LOGO: b = beat_wave(health, now) img = draw_logo(logo_source, LOGO_REST_SCALE + (LOGO_PEAK_SCALE - LOGO_REST_SCALE) * b) elif health == OFF: img = draw_menu(font) else: img = draw_waves(health, now, font) try: ser.write(hdlc_encoding.encode(img_to_bytes(img))) # the board replies with 1 status byte + 4 bytes of its clock reply = ser.read(5) except (serial.SerialException, OSError): reply = b"" if len(reply) < 5: print("Lost the board; reconnecting...") try: ser.close() except Exception: pass time.sleep(RECONNECT_EVERY_S) ser = connect(args.port) continue status = reply[0] health = status & 0b11 view = (status >> 2) & 1 now = int.from_bytes(reply[1:5], "little") if __name__ == "__main__": main()