CircuitPython Espressif Monitor mode ambient frame count per channel

ambient.py

import time
import wifi

QUEUELEN = 128  # ESP32-S2 (ESP32-S3 can be much longer)
NS_PER_CH = 5_000_000_000  # nanoseconds per channel

def monitor_ambient(channel, duration):
    report = {}

    monitor = wifi.Monitor()
    monitor.deinit()
    monitor = wifi.Monitor(channel=channel, queue=QUEUELEN)

    # maxq is the longest the core queue gets during the channel sampling period
    report["maxq"] = 0
    # total count of frames lost because the core queue was full
    report["lost"] = 0
    report["frames"] = 0
    report["time"] = 0
    start_ns = time.monotonic_ns()
    while True:
        # queue stats
        if monitor.queued() > report["maxq"]:
            report["maxq"] = monitor.queued()
        report["lost"] += monitor.lost()

        # frame stats
        received = monitor.packet()
        if received != {}:
            report["frames"] += 1

        elapsed_ns = time.monotonic_ns() - start_ns
        if elapsed_ns > duration:
            report["time"] = elapsed_ns
            report["fps"] = 1_000_000_000 * (report["frames"] / report["time"])
            break
    return report

while True:
    print("-"*49)
    print("Count ambient frames...")
    print(f' Ch frames/s queued lost')
    for channel in range(1, 14):
        print(f' {channel:2d}...', end="\r")
        report = monitor_ambient(channel, NS_PER_CH)
        print(f' {channel:2d}', end="")
        print(f'{report["fps"]:9.1f}', end="")
        print(f'{report["maxq"]:7d}', end="")
        print(f'{report["lost"]:5d}')

Sample output:

-------------------------------------------------
Count ambient frames...
 Ch frames/s queued lost
  1     77.6      2    0
  2      4.6      1    0
  3      2.2      1    0
  4      1.0      1    0
  5      0.6      1    0
  6      9.2      1    0
  7      1.0      1    0
  8      1.2      1    0
  9      0.8      1    0
 10      5.6      1    0
 11    155.6     18    0
 12      3.8      1    0
 13      0.0      0    0