UDP Client example (NTP)

Author: anecdata

examples/esp32spi_udp_client.py

@@ -0,0 +1,47 @@
+# SPDX-FileCopyrightText: 2021 Adafruit Industries
+# SPDX-License-Identifier: MIT
+
+import struct
+import time
+import board
+from digitalio import DigitalInOut
+from adafruit_esp32spi import adafruit_esp32spi
+import adafruit_esp32spi.adafruit_esp32spi_socket as socket
+from secrets import secrets
+
+
+TIMEOUT = 5
+# edit host and port to match server
+HOST = "pool.ntp.org"
+PORT = 123
+NTP_TO_UNIX_EPOCH = 2208988800  # 1970-01-01 00:00:00
+
+# PyPortal or similar; edit pins as needed
+spi = board.SPI()
+esp32_cs = DigitalInOut(board.ESP_CS)
+esp32_ready = DigitalInOut(board.ESP_BUSY)
+esp32_reset = DigitalInOut(board.ESP_RESET)
+esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
+
+# connect to wifi AP
+esp.connect(secrets)
+
+# test for connectivity to server
+print("Server ping:", esp.ping(HOST), "ms")
+
+# create the socket
+socket.set_interface(esp)
+socketaddr = socket.getaddrinfo(HOST, PORT)[0][4]
+s = socket.socket()
+s.settimeout(TIMEOUT)
+
+print("Sending")
+s.connect(socketaddr, esp.UDP_MODE)
+packet = bytearray(48)
+packet[0] = 0b00100011  # Not leap second, NTP version 4, Client mode
+s.send(packet, conntype=esp.UDP_MODE)
+
+print("Receiving")
+packet = s.recv(48)
+seconds = struct.unpack_from("!I", packet, offset=len(packet) - 8)[0]
+print("Time:", time.localtime(seconds - NTP_TO_UNIX_EPOCH))