Re-Enable the battery monitoring on Enviro! 🥳

enviro/__init__.py

@@ -2,6 +2,9 @@
 # ===========================================================================
 from enviro.constants import *
 from machine import Pin
+
+from enviro.util_functions import get_battery_voltage
+
 hold_vsys_en_pin = Pin(HOLD_VSYS_EN_PIN, Pin.OUT, value=True)
 
 # detect board model based on devices on the i2c bus and pin state
@@ -105,24 +108,6 @@ 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
@@ -176,7 +161,7 @@ def connect_to_wifi():
   logging.info("  - ip address: ", ip)
   """
   import rp2
-  rp2.country("GB") 
+  rp2.country("GB")
   wlan = network.WLAN(network.STA_IF)
   wlan.active(True)
   wlan.connect(wifi_ssid, wifi_password)
@@ -224,7 +209,7 @@ def low_disk_space():
     return (os.statvfs(".")[3] / os.statvfs(".")[2]) < 0.1   
   return False
 
-# returns True if the rtc clock has been set recently 
+# returns True if the rtc clock has been set recently
 def is_clock_set():
   # is the year on or before 2020?
   if rtc.datetime()[0] <= 2020:
@@ -283,10 +268,10 @@ def sync_clock_from_ntp():
     return False
 
   logging.info("  - rtc synched")
-  
+
   # write out the sync time log
   with open("sync_time.txt", "w") as syncfile:
-    syncfile.write("{0:04d}-{1:02d}-{2:02d}T{3:02d}:{4:02d}:{5:02d}Z".format(*timestamp))  
+    syncfile.write("{0:04d}-{1:02d}-{2:02d}T{3:02d}:{4:02d}:{5:02d}Z".format(*timestamp))
 
   return True
 
@@ -354,8 +339,10 @@ def get_sensor_readings():
     logging.info(f"  - seconds since last reading: {seconds_since_last}")
 
 
-  readings = get_board().get_sensor_readings(seconds_since_last, vbus_present)
-  # readings["voltage"] = 0.0 # battery_voltage #Temporarily removed until issue is fixed
+  readings = get_board().get_sensor_readings(seconds_since_last)
+  if hasattr(config, 'enable_battery_voltage') and config.enable_battery_voltage:
+    readings["voltage"] = get_battery_voltage()
+
 
   # write out the last time log
   with open("last_time.txt", "w") as timefile:
@@ -438,7 +425,7 @@ def upload_readings():
             # remove the sync time file to trigger a resync on next boot
             if helpers.file_exists("sync_time.txt"):
               os.remove("sync_time.txt")
-             
+
             # write out that we want to attempt a reupload
             with open("reattempt_upload.txt", "w") as attemptfile:
               attemptfile.write("")

enviro/config_template.py

@@ -24,6 +24,9 @@
 # how often to upload data (number of cached readings)
 upload_frequency = 5
 
+# Feature toggles
+enable_battery_voltage = False
+
 # web hook settings
 custom_http_url = None
 custom_http_username = None

enviro/util_functions.py

@@ -0,0 +1,30 @@
+import machine
+
+ADC_VOLT_CONVERSATION = 3.3 / 65535
+
+
+def set_pad(gpio, value):
+  machine.mem32[0x4001c000 | (4 + (4 * gpio))] = value
+
+
+def get_pad(gpio):
+  return machine.mem32[0x4001c000 | (4 + (4 * gpio))]
+
+
+def get_battery_voltage():
+  old_pad = get_pad(29)
+  set_pad(29, 128)  # no pulls, no output, no input
+
+  sample_count = 10
+  battery_voltage = 0
+  for i in range(0, sample_count):
+    battery_voltage += _read_vsys_voltage()
+  battery_voltage /= sample_count
+  battery_voltage = round(battery_voltage, 3)
+  set_pad(29, old_pad)
+  return battery_voltage
+
+
+def _read_vsys_voltage():
+  adc_Vsys = machine.ADC(3)
+  return adc_Vsys.read_u16() * 3.0 * ADC_VOLT_CONVERSATION