feat(espnow): add debug logging and channel diagnostics

Co-authored-by: Cursor <cursoragent@cursor.com>

tests/device_test_send_ch5.py

@@ -0,0 +1,47 @@
+"""Device test: send one ESP-NOW packet on channel 5 (MicroPython)."""
+
+import espnow
+import machine
+import network
+import ubinascii
+
+
+CHANNEL = 5
+DEST_HEX = "ffffffffffff"
+PAYLOAD_HEX = "4c0501000000"
+WDT_TIMEOUT_MS = 10000
+
+
+def _set_channel(channel):
+    sta = network.WLAN(network.STA_IF)
+    sta.active(True)
+    sta.config(pm=network.WLAN.PM_NONE)
+    sta.config(channel=channel)
+
+
+def _add_peer(esp, dest, channel):
+    try:
+        esp.add_peer(dest, channel=channel)
+    except TypeError:
+        esp.add_peer(dest)
+    except OSError:
+        pass
+
+
+def send_once(dest_hex=DEST_HEX, payload_hex=PAYLOAD_HEX, channel=CHANNEL):
+    wdt = machine.WDT(timeout=WDT_TIMEOUT_MS)
+    wdt.feed()
+    dest = ubinascii.unhexlify(dest_hex)
+    pkt = ubinascii.unhexlify(payload_hex)
+    _set_channel(channel)
+    e = espnow.ESPNow()
+    e.active(True)
+    _add_peer(e, dest, channel)
+    wdt.feed()
+    ok = e.send(dest, pkt, True)
+    print("sent", ok, "ch", channel, "dest", dest_hex, "len", len(pkt))
+    return ok
+
+
+if __name__ == "__main__":
+    send_once()