feat: Add INA219 battery sensor

src/jukebox/components/battery_monitor/batt_mon_i2c_ina219/__init__.py

@@ -0,0 +1,94 @@
+# MIT License
+#
+# Copyright (c) 2021 Arne Pagel
+#
+# Permission is hereby granted, free of charge, to any person obtaining a copy
+# of this software and associated documentation files (the "Software"), to deal
+# in the Software without restriction, including without limitation the rights
+# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+# copies of the Software, and to permit persons to whom the Software is
+# furnished to do so, subject to the following conditions:
+#
+# The above copyright notice and this permission notice shall be included in all
+# copies or substantial portions of the Software.
+#
+# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+# SOFTWARE.
+#
+# Contributing author(s):
+# - Arne Pagel
+
+import logging
+import jukebox.plugs as plugs
+import jukebox.cfghandler
+from ina219 import INA219
+from ina219 import DeviceRangeError
+from components.battery_monitor import BatteryMonitorBase
+
+logger = logging.getLogger('jb.battmon')
+
+batt_mon = None
+
+
+class battmon_ina219(BatteryMonitorBase.BattmonBase):
+    '''Battery Monitor based on a INA219
+
+    CAUTION - WARNING
+    ========================================================================
+    Lithium and other batteries are dangerous and must be treated with care.
+    Rechargeable Lithium Ion batteries are potentially hazardous and can
+    present a serious FIRE HAZARD if damaged, defective or improperly used.
+    Do not use this circuit to a lithium ion battery without expertise and
+    training in handling and use of batteries of this type.
+    Use appropriate test equipment and safety protocols during development.
+
+    There is no warranty, this may not work as expected or at all!
+    =========================================================================
+
+    This script is intended to read out the Voltage of a single Cell LiIon Battery using a board with a INA219:
+
+                                                  3.3V
+                                                   +
+                                                   |
+                                              .----o----.
+                                              |         |  SDA
+              .-------------------------------o AIN     o------
+              |                               | INA219  |  SCL
+              |                    .----------o AOUT    o------
+             ---                   |          |         |
+     Battery  -           Regulator + Raspi   '----o----'
+     2.9V-4.2V|                    |               |
+              |                    |               |
+             ===                  ===             ===
+
+    '''
+
+    def __init__(self, cfg):
+        super().__init__(cfg, logger)
+
+    def init_batt_mon_hw(self, num, denom):
+        self.adc = INA219(float(num) / 1000, busnum=1)
+        self.adc.configure(self.adc.RANGE_16V, self.adc.GAIN_AUTO, self.adc.ADC_32SAMP, self.adc.ADC_32SAMP)
+
+    def get_batt_voltage(self):
+        batt_voltage_mV = self.adc.supply_voltage() * 1000.0
+        return int(batt_voltage_mV)
+
+
+@plugs.finalize
+def finalize():
+    global batt_mon
+    cfg = jukebox.cfghandler.get_handler('jukebox')
+    batt_mon = battmon_ina219(cfg)
+    plugs.register(batt_mon, name='batt_mon')
+
+
+@plugs.atexit
+def atexit(**ignored_kwargs):
+    global batt_mon
+    batt_mon.status_thread.cancel()