diff --git a/scripts/mpremote_send_ch5.sh b/scripts/mpremote_send_ch5.sh
new file mode 100755
index 0000000..f67a528
--- /dev/null
+++ b/scripts/mpremote_send_ch5.sh
@@ -0,0 +1,24 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+# Upload and run a device-side ESP-NOW sender script.
+# Default channel is 5 and default destination is broadcast.
+#
+# Usage:
+#   scripts/mpremote_send_ch5.sh [port] [dest_mac_hex] [payload_hex]
+#
+# Examples:
+#   scripts/mpremote_send_ch5.sh /dev/ttyACM0
+#   scripts/mpremote_send_ch5.sh /dev/ttyACM0 ffffffffffff 4c0501000000
+
+PORT="${1:-/dev/ttyACM0}"
+DEST_HEX="${2:-ffffffffffff}"
+PAYLOAD_HEX="${3:-4c0501000000}"
+CHANNEL=5
+DEVICE_SCRIPT="send_ch5.py"
+
+mpremote connect "${PORT}" fs cp "scripts/mpremote_send_ch5_device.py" ":${DEVICE_SCRIPT}"
+mpremote connect "${PORT}" exec "
+import ${DEVICE_SCRIPT%.*}
+${DEVICE_SCRIPT%.*}.send_once('${DEST_HEX}', '${PAYLOAD_HEX}', ${CHANNEL})
+"
diff --git a/scripts/mpremote_send_ch5_device.py b/scripts/mpremote_send_ch5_device.py
new file mode 100644
index 0000000..8d27502
--- /dev/null
+++ b/scripts/mpremote_send_ch5_device.py
@@ -0,0 +1,42 @@
+"""Device-side ESP-NOW sender (MicroPython, channel 5)."""
+
+import espnow
+import network
+import ubinascii
+
+
+CHANNEL = 5
+DEST_HEX = "ffffffffffff"
+PAYLOAD_HEX = "4c0501000000"
+
+
+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):
+    dest = ubinascii.unhexlify(dest_hex)
+    pkt = ubinascii.unhexlify(payload_hex)
+    _set_channel(channel)
+    e = espnow.ESPNow()
+    e.active(True)
+    _add_peer(e, dest, channel)
+    ok = e.send(dest, pkt, True)
+    print("sent", ok, "ch", channel, "dest", dest_hex, "len", len(pkt))
+    return ok
+
+
+if __name__ == "__main__":
+    send_once()