Removes issue comment and fixes lost (rebasing) config backwards comp…

…atibility for feature toggle

enviro/__init__.py

@@ -105,24 +105,6 @@ def stop_activity_led():
 # read the state of vbus to know if we were woken up by USB
 vbus_present = Pin("WL_GPIO2", Pin.IN).value()
 
-#BUG Temporarily disabling battery reading, as it seems to cause issues when connected to Thonny
-"""
-# read battery voltage - we have to toggle the wifi chip select
-# pin to take the reading - this is probably not ideal but doesn't
-# seem to cause issues. there is no obvious way to shut down the
-# wifi for a while properly to do this (wlan.disonnect() and
-# wlan.active(False) both seem to mess things up big style..)
-old_state = Pin(WIFI_CS_PIN).value()
-Pin(WIFI_CS_PIN, Pin.OUT, value=True)
-sample_count = 10
-battery_voltage = 0
-for i in range(0, sample_count):
-  battery_voltage += (ADC(29).read_u16() * 3.3 / 65535) * 3
-battery_voltage /= sample_count
-battery_voltage = round(battery_voltage, 3)
-Pin(WIFI_CS_PIN).value(old_state)
-"""
-
 # set up the button, external trigger, and rtc alarm pins
 rtc_alarm_pin = Pin(RTC_ALARM_PIN, Pin.IN, Pin.PULL_DOWN)
 # BUG This should only be set up for Enviro Camera
@@ -355,7 +337,7 @@ def get_sensor_readings():
 
 
   readings = get_board().get_sensor_readings(seconds_since_last)
-  if config.enable_battery_voltage:
+  if hasattr(config, 'enable_battery_voltage') and config.enable_battery_voltage:
     readings["voltage"] = get_battery_voltage()