WIP: First working example for an async background task

software/boards/RPI_PICO_W/manifest.py

@@ -9,7 +9,10 @@ module("rp2_neopixel.py", "../../src")
 require("sdcard")
 require("aiorepl")
 
+# Third party modules
 module("mfrc522.py", "../../lib/micropython-mfrc522/")
 module("microdot.py", "../../lib/microdot/src/microdot/")
 
+# TonberryPico modules
 module("audiocore.py", "../../src/audiocore")
+package("nfc", base_path="../../src/")

software/src/nfc/__init__.py

@@ -0,0 +1 @@
+from nfc.nfc import Nfc

software/src/nfc/main.py

@@ -0,0 +1,12 @@
+import asyncio
+
+from nfc import Nfc
+
+async def main():
+    n = Nfc()
+    while True:
+        await asyncio.sleep_ms(500)
+        print(f'{n.get_last_uid()}')
+
+
+asyncio.run(main())

software/src/nfc/nfc.py

@@ -0,0 +1,37 @@
+import asyncio
+import time
+
+from mfrc522 import MFRC522
+
+class Nfc:
+    def __init__(self):
+        self.reader = MFRC522(spi_id=1, sck=10, miso=12, mosi=11, cs=13, rst=9, tocard_retries=10)
+        self.last_uid = None
+        self.last_uid_timestamp = None
+        self.task = asyncio.create_task(self._reader_poll_task())
+
+
+    @staticmethod
+    def uid_to_string(uid: list):
+        return '0x' + ''.join(f'{i:02x}' for i in uid)
+
+
+    async def _reader_poll_task(self, poll_interval_ms: int = 50) -> list:
+        print('reader_poll_task alive')
+
+        while True:
+            self.reader.init()
+
+            # For now we omit the tag type
+            (stat, _) = self.reader.request(self.reader.REQIDL)
+            if stat == self.reader.OK:
+                (stat, uid) = self.reader.SelectTagSN()
+                if stat == self.reader.OK:
+                    self.last_uid = uid
+                    self.last_uid_timestamp = time.ticks_us()
+
+            await asyncio.sleep_ms(poll_interval_ms)
+
+
+    def get_last_uid(self):
+        return self.last_uid, self.last_uid_timestamp