features/unit/weight: integrates a HX711 24 bits A/D chip

Author: pandiannano

m5stack/libs/unit/__init__.py

@@ -32,3 +32,5 @@
 from .ultrasonic_i2c import ULTRASONIC_I2CUnit
 from .limit import LIMITUnit
 from .op import OPUnit
+from .weight import WEIGHTUnit
+from .scales import SCALESUnit

m5stack/libs/unit/manifest.py

@@ -37,6 +37,8 @@
         # "can.py",
         "limit.py",
         "op.py",
+        "weight.py",
+        "scales.py",
     ),
     base_path="..",
     opt=0,

m5stack/libs/unit/weight.py

@@ -0,0 +1,73 @@
+from machine import Pin
+import time
+from micropython import const
+
+CHANNEL_A_128 = const(1)
+CHANNEL_A_64 = const(3)
+CHANNEL_B_32 = const(2)
+
+DATA_BITS = const(24)
+MAX_VALUE = const(0x7fffff)
+MIN_VALUE = const(0x800000)
+
+class WEIGHTUnit:
+    def __init__(self, port) -> None:
+        self.hx711data = Pin(port[0], Pin.IN)
+        self.hx711clk = Pin(port[1], Pin.OUT)
+        self.zero_value = 0
+        self.hx711clk.value(0)
+        self._channel=1
+        self._scale=1.0
+        
+    @property
+    def get_raw_weight(self) -> int:
+        count = 0
+        if self.is_ready_wait():
+            for i in range(24):
+                self.hx711clk.value(1)
+                time.sleep_us(1)
+                self.hx711clk.value(0)
+                time.sleep_us(1)
+                if self.hx711data.value():
+                    count += 1
+                count = count << 1
+        else:
+            return 0
+        
+        gain_m = self._channel
+        while gain_m:
+            self.hx711clk.value(1)
+            time.sleep_us(1)
+            self.hx711clk.value(0)
+            time.sleep_us(1)
+            gain_m -= 1
+        count = count ^ 0x800000
+        return count
+
+    @property
+    def get_scale_weight(self) -> int:
+        return int((self.get_raw_weight - self.zero_value) * self._scale)
+
+    def set_tare(self) -> None:
+        self.zero_value = self.get_raw_weight
+    
+    def set_calibrate_scale(self, weight):
+        self._scale = (1.0 * weight) / (self.get_raw_weight - self.zero_value)
+
+    def is_ready_wait(self) -> bool:
+        times = 0
+        while self.hx711data.value():
+            times += 1
+            time.sleep_ms(10)
+            if times > 25: 
+                break 
+        return not self.hx711data.value()
+    
+    def set_channel(self, chan: int) -> None:
+        self._channel = chan
+        for i in range(self._channel):
+            self.hx711clk.value(1)
+            time.sleep_us(1)
+            self.hx711clk.value(0)
+            time.sleep_us(1)
+