Jimmy
8689bdb6ef
Adjust .gitignore to ignore esp32/* except *.py so firmware .bin stays untracked. Made-with: Cursor
63 lines
1.8 KiB
Python
63 lines
1.8 KiB
Python
# Serial-to-ESP-NOW bridge: receives from Pi on UART, forwards to ESP-NOW peers.
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# Wire format: first 6 bytes = destination MAC, rest = payload. Address is always 6 bytes.
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from machine import Pin, UART
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import espnow
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import network
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import time
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UART_BAUD = 912000
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BROADCAST = b"\xff\xff\xff\xff\xff\xff"
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MAX_PEERS = 20
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network.WLAN(network.STA_IF).active(True)
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esp = espnow.ESPNow()
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esp.active(True)
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esp.add_peer(BROADCAST)
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uart = UART(1, UART_BAUD, tx=Pin(21), rx=Pin(6))
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# Track last send time per peer for LRU eviction (remove oldest when at limit).
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last_used = {BROADCAST: time.ticks_ms()}
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# ESP_ERR_ESPNOW_EXIST: peer already registered (ignore when adding).
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ESP_ERR_ESPNOW_EXIST = -12395
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def ensure_peer(addr):
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"""Ensure addr is in the peer list. When at 20 peers, remove the oldest-used (LRU)."""
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peers = esp.get_peers()
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peer_macs = [p[0] for p in peers]
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if addr in peer_macs:
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return
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if len(peer_macs) >= MAX_PEERS:
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# Remove the peer we used least recently (oldest).
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oldest_mac = None
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oldest_ts = time.ticks_ms()
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for mac in peer_macs:
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if mac == BROADCAST:
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continue
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ts = last_used.get(mac, 0)
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if ts <= oldest_ts:
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oldest_ts = ts
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oldest_mac = mac
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if oldest_mac is not None:
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esp.del_peer(oldest_mac)
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last_used.pop(oldest_mac, None)
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try:
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esp.add_peer(addr)
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except OSError as e:
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if e.args[0] != ESP_ERR_ESPNOW_EXIST:
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raise
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while True:
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if uart.any():
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data = uart.read()
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if not data or len(data) < 6:
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continue
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addr = data[:6]
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payload = data[6:]
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ensure_peer(addr)
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esp.send(addr, payload)
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last_used[addr] = time.ticks_ms() |