Vibe coded some untrustworthy test scripts

scripts/speed_test2.py

@@ -0,0 +1,224 @@
+#!/usr/bin/env python3
+
+import serial
+import threading
+import time
+
+# ==========================================================
+# Configuration
+# ==========================================================
+
+PORT = "/dev/ttyACM0"
+BAUDRATE = 115200
+
+COMMAND_PREFIX = 0x69
+
+COMMAND_ACK = 0
+COMMAND_NACK = 1
+LED = 2
+
+DEVICE_ID = 0
+
+TEST_DURATION = 5.0
+ACK_TIMEOUT = 1.0
+
+# ==========================================================
+# Packet helpers
+# ==========================================================
+
+def calculate_crc(msg: bytes) -> int:
+    return (-sum(msg)) & 0xFF
+
+
+def make_packet(command: int, data: bytes = b"") -> bytes:
+    pkt = bytearray()
+
+    pkt.append(COMMAND_PREFIX)
+    pkt.append(len(data))
+    pkt.append(DEVICE_ID)
+    pkt.append(command)
+    pkt.append(0)
+
+    pkt.extend(data)
+
+    pkt[4] = calculate_crc(pkt[:4] + pkt[5:])
+    return bytes(pkt)
+
+
+def verify_crc(packet: bytes) -> bool:
+    return packet[4] == calculate_crc(packet[:4] + packet[5:])
+
+
+# ==========================================================
+# ACK synchronization
+# ==========================================================
+
+ack_event = threading.Event()
+
+ack_count = 0
+nack_count = 0
+error_count = 0
+timeout_count = 0
+
+running = True
+
+
+# ==========================================================
+# Receiver
+# ==========================================================
+
+def reader(ser):
+    global ack_count
+    global nack_count
+    global error_count
+
+    rx = bytearray()
+
+    while running:
+
+        data = ser.read(4096)
+
+        if not data:
+            continue
+
+        rx.extend(data)
+
+        while True:
+
+            if len(rx) < 5:
+                break
+
+            if rx[0] != COMMAND_PREFIX:
+
+                nl = rx.find(b"\n")
+
+                if nl == -1:
+                    rx.clear()
+                    break
+
+                try:
+                    print("[LOG]", rx[:nl].decode().rstrip())
+                except UnicodeDecodeError:
+                    pass
+
+                del rx[: nl + 1]
+                continue
+
+            length = rx[1]
+            size = 5 + length
+
+            if len(rx) < size:
+                break
+
+            pkt = bytes(rx[:size])
+            del rx[:size]
+
+            if not verify_crc(pkt):
+                continue
+
+            cmd = pkt[3]
+
+            if cmd == COMMAND_ACK:
+                ack_count += 1
+                ack_event.set()
+
+            elif cmd == COMMAND_NACK:
+                nack_count += 1
+                ack_event.set()
+
+            elif cmd == COMMAND_ERROR:
+                error_count += 1
+                ack_event.set()
+
+
+# ==========================================================
+# Benchmark
+# ==========================================================
+
+def benchmark(ser):
+
+    global timeout_count
+
+    packet = make_packet(LED)
+
+    sent = 0
+
+    rtt_sum = 0.0
+    rtt_min = float("inf")
+    rtt_max = 0.0
+
+    start = time.perf_counter()
+    end = start + TEST_DURATION
+
+    while time.perf_counter() < end:
+
+        ack_event.clear()
+
+        t0 = time.perf_counter()
+
+        ser.write(packet)
+
+        if not ack_event.wait(ACK_TIMEOUT):
+            timeout_count += 1
+            continue
+
+        t1 = time.perf_counter()
+
+        rtt = t1 - t0
+
+        sent += 1
+        rtt_sum += rtt
+        rtt_min = min(rtt_min, rtt)
+        rtt_max = max(rtt_max, rtt)
+
+    elapsed = time.perf_counter() - start
+
+    print()
+    print("=" * 60)
+    print(f"Elapsed      : {elapsed:.3f} s")
+    print(f"Sent         : {sent}")
+    print(f"ACK          : {ack_count}")
+    print(f"NACK         : {nack_count}")
+    print(f"ERROR        : {error_count}")
+    print(f"Timeouts     : {timeout_count}")
+    print(f"Packet Rate  : {sent / elapsed:.1f} pkt/s")
+
+    if sent:
+        print(f"Mean RTT     : {1000*rtt_sum/sent:.3f} ms")
+        print(f"Min RTT      : {1000*rtt_min:.3f} ms")
+        print(f"Max RTT      : {1000*rtt_max:.3f} ms")
+
+
+# ==========================================================
+# Main
+# ==========================================================
+
+def main():
+
+    global running
+
+    print(f"Opening {PORT}")
+
+    ser = serial.Serial(
+        PORT,
+        BAUDRATE,
+        timeout=0.01,
+    )
+
+    threading.Thread(
+        target=reader,
+        args=(ser,),
+        daemon=True,
+    ).start()
+
+    print("Running benchmark...")
+
+    benchmark(ser)
+
+    running = False
+
+    ser.close()
+
+
+if __name__ == "__main__":
+    main()