初始化提交

boards/default/micropython/build/lib/pm2_5.py

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+"""
+PM2.5
+
+Micropython library for the PM2.5(UART)
+=======================================================
+#Preliminary composition        20220908
+
+dahanzimin From the Mixly Team 
+"""
+import time
+
+class PM2_5:
+    def __init__(self, uart):
+        self._uart=uart
+        self._uart.init(baudrate=9600)
+        self._pm=(0,0)
+        self._flag=False
+        if not self._chip_id():
+            raise AttributeError("Cannot find a PM2.5")
+    
+    def _rreg(self):
+        '''Read data'''
+        if self._uart.any():
+            eec=0
+            buf=self._uart.read(7)
+            for i in buf[1:5]:
+                eec+=i
+            if (eec & 0xff) == buf[5] and buf[0] == 0xAA and buf[6] == 0xFF:
+                self._pm=(buf[1] << 8 | buf[2] , buf[3] << 8 | buf[4] )
+                return True
+
+    def _chip_id(self):
+        for _ in range(5):
+            if self._rreg():
+                return True
+            time.sleep(1)
+        return False
+
+    def concentration(self):
+        self._rreg()
+        return  self._pm