remove reset from init

Author: caternuson

adafruit_scd30.py

@@ -61,8 +61,6 @@ def __init__(self, i2c_bus, ambient_pressure=0, address=SCD30_DEFAULT_ADDR):
         self._buffer = bytearray(18)
         self._crc_buffer = bytearray(2)
 
-        self.reset()
-
         # set continuous measurement interval in seconds
         self.measurement_interval = 2
         # activate automatic self-calibration
@@ -79,13 +77,6 @@ def reset(self):
         """Perform a soft reset on the sensor, restoring default values"""
         self._send_command(_CMD_SOFT_RESET)
         sleep(0.1)  # not mentioned by datasheet, but required to avoid IO error
-        # pylint:disable=protected-access
-        # are we using Blinka?
-        if hasattr(self.i2c_device.i2c, "_i2c"):
-            # with an MCP2221?
-            if hasattr(self.i2c_device.i2c._i2c, "_mcp2221"):
-                # then lets reset that too
-                self.i2c_device.i2c._i2c._mcp2221._reset()
 
     @property
     def measurement_interval(self):

examples/scd30_reset.py

@@ -0,0 +1,38 @@
+# SPDX-FileCopyrightText: 2021 by Carter Nelson, written for Adafruit Industries
+#
+# SPDX-License-Identifier: Unlicense
+import time
+import board
+import busio
+import adafruit_scd30
+
+i2c = busio.I2C(board.SCL, board.SDA)
+scd = adafruit_scd30.SCD30(i2c)
+
+# The SCD30 reset generates a hiccup on the SCL and SDA lines
+# which can end up not being handled well by different hosts.
+scd.reset()
+
+# The MCP2221 is known to not like the SCD30 reset hiccup.
+# See below for more information:
+# https://github.com/adafruit/Adafruit_CircuitPython_SCD30/issues/2
+# Can get around it by resetting via this hack.
+if hasattr(i2c, "_i2c"):
+    # we're using Blinka, check for MCP2221
+    if hasattr(i2c._i2c, "_mcp2221"):
+        # reset it
+        i2c._i2c._mcp2221._reset()
+
+while True:
+    # since the measurement interval is long (2+ seconds) we check for new data before reading
+    # the values, to ensure current readings.
+    if scd.data_available:
+        print("Data Available!")
+        print("CO2:", scd.CO2, "PPM")
+        print("Temperature:", scd.temperature, "degrees C")
+        print("Humidity:", scd.relative_humidity, "%%rH")
+        print("")
+        print("Waiting for new data...")
+        print("")
+
+    time.sleep(0.5)