Raw ntp

adafruit_ntp.py

@@ -36,42 +36,50 @@
    https://github.com/adafruit/circuitpython/releases
 
 """
+import struct
 import time
-import rtc
 
 __version__ = "0.0.0-auto.0"
 __repo__ = "https://github.com/adafruit/Adafruit_CircuitPython_NTP.git"
 
+NTP_TO_UNIX_EPOCH = 2208988800  # 1970-01-01 00:00:00
 
 class NTP:
     """Network Time Protocol (NTP) helper module for CircuitPython.
-    This module does not handle daylight savings or local time.
+    This module does not handle daylight savings or local time. It simply requests
+    UTC from a NTP server.
 
-    :param adafruit_esp32spi esp: ESP32SPI object.
+    :param object socketpool: A socket provider such as CPython's `socket` module.
     """
 
-    def __init__(self, esp):
-        # Verify ESP32SPI module
-        if "ESP_SPIcontrol" in str(type(esp)):
-            self._esp = esp
-        else:
-            raise TypeError("Provided object is not an ESP_SPIcontrol object.")
-        self.valid_time = False
+    def __init__(self, socketpool, *, server="pool.ntp.org", port=123):
+        self._pool = socketpool
+        self._server = server
+        self._port = port
+        self._packet = bytearray(48)
 
-    def set_time(self, tz_offset=0):
-        """Fetches and sets the microcontroller's current time
-        in seconds since since Jan 1, 1970.
 
-        :param int tz_offset: The offset of the local timezone,
-            in seconds west of UTC (negative in most of Western Europe,
-            positive in the US, zero in the UK).
-        """
+        # This is our estimated start time for the monotonic clock.
+        # We adjust it based on the ntp responses.
+        self._monotonic_start = 0
 
-        try:
-            now = self._esp.get_time()
-            now = time.localtime(now[0] + tz_offset)
-            rtc.RTC().datetime = now
-            self.valid_time = True
-        except ValueError as error:
-            print(str(error))
-            return
+        self.next_sync = 0
+
+    @property
+    def datetime(self):
+        if time.monotonic_ns() > self.next_sync:
+            self._packet[0] = 0b00100011  # Not leap second, NTP version 4, Client mode
+            for i in range(1, len(self._packet)):
+                self._packet[i] = 0
+            with self._pool.socket(self._pool.AF_INET, self._pool.SOCK_DGRAM) as sock:
+                sock.sendto(self._packet, (self._server, self._port))
+                size, address = sock.recvfrom_into(self._packet)
+                # Get the time in the context to minimize the difference between it and receiving
+                # the packet.
+                destination = time.monotonic_ns()
+            poll = struct.unpack_from("!B", self._packet, offset=2)[0]
+            self.next_sync = destination + (2 ** poll) * 1_000_000_000
+            seconds = struct.unpack_from("!I", self._packet, offset=len(self._packet) - 8)[0]
+            self._monotonic_start = seconds - NTP_TO_UNIX_EPOCH - (destination // 1_000_000_000)
+
+        return time.localtime(time.monotonic_ns() // 1_000_000_000 + self._monotonic_start)

examples/ntp_esp32spi.py

@@ -0,0 +1,52 @@
+import time
+import board
+import busio
+from digitalio import DigitalInOut
+from adafruit_esp32spi import adafruit_esp32spi
+from adafruit_ntp import NTP
+
+# If you are using a board with pre-defined ESP32 Pins:
+esp32_cs = DigitalInOut(board.ESP_CS)
+esp32_ready = DigitalInOut(board.ESP_BUSY)
+esp32_reset = DigitalInOut(board.ESP_RESET)
+
+# If you have an externally connected ESP32:
+# esp32_cs = DigitalInOut(board.D9)
+# esp32_ready = DigitalInOut(board.D10)
+# esp32_reset = DigitalInOut(board.D5)
+
+spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
+esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
+
+print("Connecting to AP...")
+while not esp.is_connected:
+    try:
+        esp.connect_AP(b"WIFI_SSID", b"WIFI_PASS")
+    except RuntimeError as e:
+        print("could not connect to AP, retrying: ", e)
+        continue
+
+# Initialize the NTP object
+ntp = NTP(esp)
+
+# Fetch and set the microcontroller's current UTC time
+# keep retrying until a valid time is returned
+while not ntp.valid_time:
+    ntp.set_time()
+    print("Failed to obtain time, retrying in 5 seconds...")
+    time.sleep(5)
+
+# Get the current time in seconds since Jan 1, 1970
+current_time = time.time()
+print("Seconds since Jan 1, 1970: {} seconds".format(current_time))
+
+# Convert the current time in seconds since Jan 1, 1970 to a struct_time
+now = time.localtime(current_time)
+print(now)
+
+# Pretty-parse the struct_time
+print(
+    "It is currently {}/{}/{} at {}:{}:{} UTC".format(
+        now.tm_mon, now.tm_mday, now.tm_year, now.tm_hour, now.tm_min, now.tm_sec
+    )
+)

examples/ntp_simpletest.py

@@ -1,52 +1,26 @@
+import socketpool
 import time
-import board
-import busio
-from digitalio import DigitalInOut
-from adafruit_esp32spi import adafruit_esp32spi
-from adafruit_ntp import NTP
+import wifi
 
-# If you are using a board with pre-defined ESP32 Pins:
-esp32_cs = DigitalInOut(board.ESP_CS)
-esp32_ready = DigitalInOut(board.ESP_BUSY)
-esp32_reset = DigitalInOut(board.ESP_RESET)
+import adafruit_ntp
 
-# If you have an externally connected ESP32:
-# esp32_cs = DigitalInOut(board.D9)
-# esp32_ready = DigitalInOut(board.D10)
-# esp32_reset = DigitalInOut(board.D5)
 
-spi = busio.SPI(board.SCK, board.MOSI, board.MISO)
-esp = adafruit_esp32spi.ESP_SPIcontrol(spi, esp32_cs, esp32_ready, esp32_reset)
+# Add a secrets.py to your filesystem that has a dictionary called secrets with "ssid" and
+# "password" keys with your WiFi credentials. DO NOT share that file or commit it into Git or other
+# source control.
+# pylint: disable=no-name-in-module,wrong-import-order
+try:
+    from secrets import secrets
+except ImportError:
+    print("WiFi secrets are kept in secrets.py, please add them there!")
+    raise
 
-print("Connecting to AP...")
-while not esp.is_connected:
-    try:
-        esp.connect_AP(b"WIFI_SSID", b"WIFI_PASS")
-    except RuntimeError as e:
-        print("could not connect to AP, retrying: ", e)
-        continue
+wifi.radio.connect(secrets["ssid"], secrets["password"])
 
-# Initialize the NTP object
-ntp = NTP(esp)
+pool = socketpool.SocketPool(wifi.radio)
+ntp = adafruit_ntp.NTP(pool)
 
-# Fetch and set the microcontroller's current UTC time
-# keep retrying until a valid time is returned
-while not ntp.valid_time:
-    ntp.set_time()
-    print("Failed to obtain time, retrying in 5 seconds...")
-    time.sleep(5)
-
-# Get the current time in seconds since Jan 1, 1970
-current_time = time.time()
-print("Seconds since Jan 1, 1970: {} seconds".format(current_time))
-
-# Convert the current time in seconds since Jan 1, 1970 to a struct_time
-now = time.localtime(current_time)
-print(now)
-
-# Pretty-parse the struct_time
-print(
-    "It is currently {}/{}/{} at {}:{}:{} UTC".format(
-        now.tm_mon, now.tm_mday, now.tm_year, now.tm_hour, now.tm_min, now.tm_sec
-    )
-)
+while True:
+    print(ntp.datetime)
+    time.sleep(1)
+

examples/ntp_simpletest_cpython.py

@@ -0,0 +1,9 @@
+import adafruit_ntp
+import socket
+import time
+
+ntp = adafruit_ntp.NTP(socket)
+
+while True:
+    print(ntp.datetime)
+    time.sleep(1)