7fa322afb8
ESP-NOW is a proprietary wireless communication protocol which supports
connectionless communication between ESP32 and ESP8266 devices, using
vendor specific WiFi frames. This commit adds support for this protocol
through a new `espnow` module.
This commit builds on original work done by @nickzoic, @shawwwn and with
contributions from @zoland. Features include:
- Use of (extended) ring buffers in py/ringbuf.[ch] for robust IO.
- Signal strength (RSSI) monitoring.
- Core support in `_espnow` C module, extended by `espnow.py` module.
- Asyncio support via `aioespnow.py` module (separate to this commit).
- Docs provided at `docs/library/espnow.rst`.
Methods available in espnow.ESPNow class are:
- active(True/False)
- config(): set rx buffer size, read timeout and tx rate
- recv()/irecv()/recvinto() to read incoming messages from peers
- send() to send messages to peer devices
- any() to test if a message is ready to read
- irq() to set callback for received messages
- stats() returns transfer stats:
(tx_pkts, tx_pkt_responses, tx_failures, rx_pkts, lost_rx_pkts)
- add_peer(mac, ...) registers a peer before sending messages
- get_peer(mac) returns peer info: (mac, lmk, channel, ifidx, encrypt)
- mod_peer(mac, ...) changes peer info parameters
- get_peers() returns all peer info tuples
- peers_table supports RSSI signal monitoring for received messages:
{peer1: [rssi, time_ms], peer2: [rssi, time_ms], ...}
ESP8266 is a pared down version of the ESP32 ESPNow support due to code
size restrictions and differences in the low-level API. See docs for
details.
Also included is a test suite in tests/multi_espnow. This tests basic
espnow data transfer, multiple transfers, various message sizes, encrypted
messages (pmk and lmk), and asyncio support.
Initial work is from https://github.com/micropython/micropython/pull/4115.
Initial import of code is from:
https://github.com/nickzoic/micropython/tree/espnow-4115.
131 lines
3.7 KiB
Python
131 lines
3.7 KiB
Python
# Test of a ESPnow echo server and client transferring encrypted data.
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# This test works with ESP32 or ESP8266 as server or client.
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# First instance (echo server):
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# Set the shared PMK
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# Set the PEERS global to our mac addresses
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# Run the echo server
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# First exchange an unencrypted message from the client (so we
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# can get its MAC address) and echo the message back (unenecrypted).
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# Then set the peer LMK so all further communications are encrypted.
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# Second instance (echo client):
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# Set the shared PMK
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# Send an unencrypted message to the server and wait for echo response.
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# Set the LMK for the peer communications so all further comms are encrypted.
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# Send random messages and compare with response from server.
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try:
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import network
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import random
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import time
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import espnow
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except ImportError:
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print("SKIP")
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raise SystemExit
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# Set read timeout to 5 seconds
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timeout_ms = 5000
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default_pmk = b"MicroPyth0nRules"
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default_lmk = b"0123456789abcdef"
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sync = True
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def echo_server(e):
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peers = []
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while True:
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# Wait for messages from the client
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peer, msg = e.recv(timeout_ms)
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if peer is None:
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return
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if peer not in peers:
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# If this is first message, add the peer unencrypted
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e.add_peer(peer)
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# Echo the message back to the sender
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if not e.send(peer, msg, sync):
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print("ERROR: send() failed to", peer)
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return
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if peer not in peers:
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# If this is first message, add the peer encrypted
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peers.append(peer)
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e.del_peer(peer)
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e.add_peer(peer, default_lmk)
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if msg == b"!done":
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return
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# Send a message from the client and compare with response from server.
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def echo_test(e, peer, msg, sync):
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print("TEST: send/recv(msglen=", len(msg), ",sync=", sync, "): ", end="", sep="")
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try:
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if not e.send(peer, msg, sync):
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print("ERROR: Send failed.")
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return
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except OSError as exc:
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# Don't print exc as it is differs for esp32 and esp8266
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print("ERROR: OSError:")
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return
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p2, msg2 = e.recv(timeout_ms)
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if p2 is None:
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print("ERROR: No response from server.")
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raise SystemExit
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print("OK" if msg2 == msg else "ERROR: Received != Sent")
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# Send some random messages to server and check the responses
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def echo_client(e, peer, msglens):
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for sync in [True, False]:
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for msglen in msglens:
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msg = bytearray(msglen)
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if msglen > 0:
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msg[0] = b"_"[0] # Random message must not start with '!'
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for i in range(1, msglen):
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msg[i] = random.getrandbits(8)
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echo_test(e, peer, msg, sync)
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# Initialise the wifi and espnow hardware and software
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def init(sta_active=True, ap_active=False):
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wlans = [network.WLAN(i) for i in [network.STA_IF, network.AP_IF]]
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e = espnow.ESPNow()
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e.active(True)
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e.set_pmk(default_pmk)
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wlans[0].active(sta_active)
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wlans[1].active(ap_active)
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wlans[0].disconnect() # Force esp8266 STA interface to disconnect from AP
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return e
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# Server
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def instance0():
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e = init(True, False)
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macs = [network.WLAN(i).config("mac") for i in (0, 1)]
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print("Server Start")
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multitest.globals(PEERS=macs)
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multitest.next()
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echo_server(e)
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print("Server Done")
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e.active(False)
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# Client
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def instance1():
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e = init(True, False)
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multitest.next()
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peer = PEERS[0]
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e.add_peer(peer)
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echo_test(e, peer, b"start", True)
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# Wait long enough for the server to set the lmk
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time.sleep(0.1)
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e.del_peer(peer)
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e.add_peer(peer, default_lmk)
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echo_client(e, peer, [250])
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echo_test(e, peer, b"!done", True)
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e.active(False)
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