Micropython espnow wrapper

Send and receive data between ESPs over espnow without worries. This library provides asynchronous message sending and receiving with support for chunked data transmission and acknowledgments.

Features

• Asynchronous ESP-NOW message handling
• Automatic chunking of large messages
• CRC32 verification for data integrity
• Optional acknowledgment (ACK) support
• Configurable timeout and cycle time
• Debugging mode for easier troubleshooting

install

Usage

Initializing the ESPNowManager

from mp_espnow_wrapper import ESPNowManager

esp_manager = ESPNowManager(peer='AA:BB:CC:DD:EE:FF', debug=True)
esp_manager.set_callback('on_receive', lambda msg: print("Received:", msg))
esp_manager.init()

Sending Messages

import asyncio

async def send():
    message = b'Hello ESP-NOW!'
    await esp_manager.send(message)

asyncio.run(send())

Receiving Messages

Call init() to start the background receive task. Register callbacks with set_callback(event, callback):

• 'on_receive': Called when a complete, verified message is received. The callback accepts one argument: the message as a bytearray.
• 'on_timeout': Called when no message is received within timeout_ms. The callback accepts no arguments.

esp_manager.set_callback('on_receive', lambda msg: print("Received:", msg))
esp_manager.set_callback('on_timeout', lambda: print("Timeout!"))

Configuration

• peer: MAC address of the target device (default: broadcast)
• rxbuf: Buffer size for incoming messages
• timeout_ms: Message receive timeout in ms
• cycle_time_ms: Interval between message chunks (ms). Needs to be > 2–3 ms for stable operation
• wait_msg_ack: Whether to wait for acknowledgment after sending. Includes the on_receive callback execution at the receiver.
• send_ack_after_cb: Whether to send ACK after the callback execution (instead of before).
• send_async: Whether to send messages asynchronously.
• debug: Enables debug output