cat > ads_stream.py <<'PY'
import sys, time, struct, smbus

BUS=1; ADDR=0x48; REG_CONV=0x00; REG_CONFIG=0x01
bus = smbus.SMBus(BUS)

# Continuous, AIN0, PGA ±4.096V, 860 SPS (chip-side)
config = 0x8000 | 0x4000 | 0x0200 | 0x0000 | 0x00E0 | 0x0003
bus.write_i2c_block_data(ADDR, REG_CONFIG, [(config>>8)&0xFF, config&0xFF])

FS=4.096
def read_v():
    raw = bus.read_word_data(ADDR, REG_CONV)
    raw = ((raw & 0xFF) << 8) | (raw >> 8)
    if raw & 0x8000: raw -= 1<<16
    return raw * FS / 32768.0

# target: ~860 samples/sec (sleep to avoid pointless 3k reads of same value)
TARGET_SPS = 860
dt = 1.0 / TARGET_SPS
t_next = time.perf_counter()

# binary: float32 volts
pack = struct.Struct("<f").pack
out = sys.stdout.buffer

while True:
    v = read_v()
    out.write(pack(v))
    # flush in chunks for speed
    if out.tell() % (4*256) == 0:
        out.flush()

    t_next += dt
    now = time.perf_counter()
    if t_next > now:
        time.sleep(t_next - now)
    else:
        # if we fell behind, resync
        t_next = now
PY

cat > plot_stream.py <<'PY'
import sys, struct, time
from collections import deque
import matplotlib.pyplot as plt

WINDOW_SECONDS = 0.5
DISPLAY_SPS = 200         # plot points/sec (decimated)
DRAW_FPS = 25

N = int(WINDOW_SECONDS * DISPLAY_SPS)
ys = deque([0.0]*N, maxlen=N)
xs = [i / DISPLAY_SPS for i in range(N)]

plt.ion()
fig, ax = plt.subplots()
line, = ax.plot(xs, list(ys))
ax.set_title(f"ADS1115 AIN0 (streamed) {WINDOW_SECONDS}s window")
ax.set_xlabel("Time (s)")
ax.set_ylabel("Volts")
ax.set_xlim(0, WINDOW_SECONDS)
ax.set_ylim(-0.5, 3.5)

unpack = struct.Struct("<f").unpack
buf = bytearray()
last_draw = time.perf_counter()
draw_interval = 1.0 / DRAW_FPS

# We receive ~860 SPS; only keep DISPLAY_SPS by skipping
IN_SPS = 860
skip = max(1, IN_SPS // DISPLAY_SPS)
k = 0

stdin = sys.stdin.buffer

while True:
    chunk = stdin.read(4*256)
    if not chunk:
        break
    buf.extend(chunk)

    # process complete floats
    while len(buf) >= 4:
        v = unpack(buf[:4])[0]
        del buf[:4]
        k += 1
        if k % skip == 0:
            ys.append(v)

    now = time.perf_counter()
    if now - last_draw >= draw_interval:
        line.set_ydata(list(ys))
        fig.canvas.draw_idle()
        plt.pause(0.001)
        last_draw = now
PY