ESP-NOW

import espnow

// Initialization
espnow.init()

// Set channel

// Get local mac_addr
espnow.get_mac_addr()

// Broadcast
espnow.broadcast(data='Hello')

// Set peer list
espnow.add_peer(slave_mac_addr, id)

// Send message
espnow.send(id, data='World')

// Send message callback
def send_cb(flag):
  if flag:
    print('succeed')
  else:
    print('Failed')

espnow.send_cb(send_cb)

// Receive message callback
def recv_cb():
    // Get data
    sender_address, _, receive_data = espnow.recv_data(encoder='str')

espnow.recv_cb(recv_cb)