bq27441: add driver for the LiPo Fuel Gauge

Author: nedseb

lib/bq27441/README.md

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+# MicroPython BQ27441 Library
+
+This library is a port of the [SparkFun BQ27441-G1A LiPo Fuel Gauge Arduino Libraryry](https://github.com/sparkfun/SparkFun_BQ27441_Arduino_Library).
+
+The examples could be easily tested with [mpremote](https://docs.micropython.org/en/latest/reference/mpremote.html) with the following command :
+
+```sh
+mpremote mount . run examples/fuel_gauge.py
+```

lib/bq27441/bq27441/__init__.py

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+from bq27441.device import BQ27441
+
+__all__ = [
+    "BQ27441",
+]

lib/bq27441/bq27441/const.py

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+# Lipo Battery Capacity
+LIPO_BATTERY_CAPACITY = 650  # 850 mAh
+
+
+BQ27441_I2C_ADDRESS = 0x55  # Default I2C address of the BQ27441-G1A
+
+# General Constants #
+BQ27441_UNSEAL_KEY = 0x8000  # Secret code to unseal the BQ27441-G1A
+BQ27441_DEVICE_ID = 0x0421  # Default device ID
+
+# Standard Commands #
+
+# The fuel gauge uses a series of 2-byte standard commands to enable system
+# reading and writing of battery information. Each command has an associated
+# sequential command-code pair.
+
+BQ27441_COMMAND_CONTROL = 0x00  # Control()
+BQ27441_COMMAND_TEMP = 0x02  # Temperature()
+BQ27441_COMMAND_VOLTAGE = 0x04  # Voltage()
+BQ27441_COMMAND_FLAGS = 0x06  # Flags()
+BQ27441_COMMAND_NOM_CAPACITY = 0x08  # NominalAvailableCapacity()
+BQ27441_COMMAND_AVAIL_CAPACITY = 0x0A  # FullAvailableCapacity()
+BQ27441_COMMAND_REM_CAPACITY = 0x0C  # RemainingCapacity()
+BQ27441_COMMAND_FULL_CAPACITY = 0x0E  # FullChargeCapacity()
+BQ27441_COMMAND_AVG_CURRENT = 0x10  # AverageCurrent()
+BQ27441_COMMAND_STDBY_CURRENT = 0x12  # StandbyCurrent()
+BQ27441_COMMAND_MAX_CURRENT = 0x14  # MaxLoadCurrent()
+BQ27441_COMMAND_AVG_POWER = 0x18  # AveragePower()
+BQ27441_COMMAND_SOC = 0x1C  # StateOfCharge()
+BQ27441_COMMAND_INT_TEMP = 0x1E  # InternalTemperature()
+BQ27441_COMMAND_SOH = 0x20  # StateOfHealth()
+BQ27441_COMMAND_REM_CAP_UNFL = 0x28  # RemainingCapacityUnfiltered()
+BQ27441_COMMAND_REM_CAP_FIL = 0x2A  # RemainingCapacityFiltered()
+BQ27441_COMMAND_FULL_CAP_UNFL = 0x2C  # FullChargeCapacityUnfiltered()
+BQ27441_COMMAND_FULL_CAP_FIL = 0x2E  # FullChargeCapacityFiltered()
+BQ27441_COMMAND_SOC_UNFL = 0x30  # StateOfChargeUnfiltered()
+
+# Control Sub-commands #
+
+# Issuing a Control() command requires a subsequent 2-byte subcommand. These
+# additional bytes specify the particular control function desired. The
+# Control() command allows the system to control specific features of the fuel
+# gauge during normal operation and additional features when the device is in
+# different access modes.
+
+BQ27441_CONTROL_STATUS = 0x00
+BQ27441_CONTROL_DEVICE_TYPE = 0x01
+BQ27441_CONTROL_FW_VERSION = 0x02
+BQ27441_CONTROL_DM_CODE = 0x04
+BQ27441_CONTROL_PREV_MACWRITE = 0x07
+BQ27441_CONTROL_CHEM_ID = 0x08
+BQ27441_CONTROL_BAT_INSERT = 0x0C
+BQ27441_CONTROL_BAT_REMOVE = 0x0D
+BQ27441_CONTROL_SET_HIBERNATE = 0x11
+BQ27441_CONTROL_CLEAR_HIBERNATE = 0x12
+BQ27441_CONTROL_SET_CFGUPDATE = 0x13
+BQ27441_CONTROL_SHUTDOWN_ENABLE = 0x1B
+BQ27441_CONTROL_SHUTDOWN = 0x1C
+BQ27441_CONTROL_SEALED = 0x20
+BQ27441_CONTROL_PULSE_SOC_INT = 0x23
+BQ27441_CONTROL_RESET = 0x41
+BQ27441_CONTROL_SOFT_RESET = 0x42
+BQ27441_CONTROL_EXIT_CFGUPDATE = 0x43
+BQ27441_CONTROL_EXIT_RESIM = 0x44
+
+# Control Status Word - Bit Definitions #
+
+# Bit positions for the 16-bit data of CONTROL_STATUS.
+# CONTROL_STATUS instructs the fuel gauge to return status information to
+# Control() addresses 0x00 and 0x01. The read-only status word contains status
+# bits that are set or cleared either automatically as conditions warrant or
+# through using specified subcommands.
+BQ27441_STATUS_SHUTDOWNEN = 1 << 15
+BQ27441_STATUS_WDRESET = 1 << 14
+BQ27441_STATUS_SS = 1 << 13
+BQ27441_STATUS_CALMODE = 1 << 12
+BQ27441_STATUS_CCA = 1 << 11
+BQ27441_STATUS_BCA = 1 << 10
+BQ27441_STATUS_QMAX_UP = 1 << 9
+BQ27441_STATUS_RES_UP = 1 << 8
+BQ27441_STATUS_INITCOMP = 1 << 7
+BQ27441_STATUS_HIBERNATE = 1 << 6
+BQ27441_STATUS_SLEEP = 1 << 4
+BQ27441_STATUS_LDMD = 1 << 3
+BQ27441_STATUS_RUP_DIS = 1 << 2
+BQ27441_STATUS_VOK = 1 << 1
+
+
+# Flag Command - Bit Definitions #
+
+# Bit positions for the 16-bit data of Flags()
+# This read-word function returns the contents of the fuel gauging status
+# register, depicting the current operating status.
+BQ27441_FLAG_OT = 1 << 15
+BQ27441_FLAG_UT = 1 << 14
+BQ27441_FLAG_FC = 1 << 9
+BQ27441_FLAG_CHG = 1 << 8
+BQ27441_FLAG_OCVTAKEN = 1 << 7
+BQ27441_FLAG_ITPOR = 1 << 5
+BQ27441_FLAG_CFGUPMODE = 1 << 4
+BQ27441_FLAG_BAT_DET = 1 << 3
+BQ27441_FLAG_SOC1 = 1 << 2
+BQ27441_FLAG_SOCF = 1 << 1
+BQ27441_FLAG_DSG = 1 << 0
+
+
+# Extended Data Commands #
+
+# Extended data commands offer additional functionality beyond the standard
+# set of commands. They are used in the same manner; however, unlike standard
+# commands, extended commands are not limited to 2-byte words.
+BQ27441_EXTENDED_OPCONFIG = 0x3A  # OpConfig()
+BQ27441_EXTENDED_CAPACITY = 0x3C  # DesignCapacity()
+BQ27441_EXTENDED_DATACLASS = 0x3E  # DataClass()
+BQ27441_EXTENDED_DATABLOCK = 0x3F  # DataBlock()
+BQ27441_EXTENDED_BLOCKDATA = 0x40  # BlockData()
+BQ27441_EXTENDED_CHECKSUM = 0x60  # BlockDataCheckSum()
+BQ27441_EXTENDED_CONTROL = 0x61  # BlockDataControl()
+
+
+# Configuration Class, Subclass ID's #
+
+# To access a subclass of the extended data, set the DataClass() function
+# with one of these values.
+# Configuration Classes
+BQ27441_ID_SAFETY = 2  # Safety
+BQ27441_ID_CHG_TERMINATION = 36  # Charge Termination
+BQ27441_ID_CONFIG_DATA = 48  # Data
+BQ27441_ID_DISCHARGE = 49  # Discharge
+BQ27441_ID_REGISTERS = 64  # Registers
+BQ27441_ID_POWER = 68  # Power
+# Gas Gauging Classes
+BQ27441_ID_IT_CFG = 80  # IT Cfg
+BQ27441_ID_CURRENT_THRESH = 81  # Current Thresholds
+BQ27441_ID_STATE = 82  # State
+# Ra Tables Classes
+BQ27441_ID_R_A_RAM = 89  # R_a RAM
+# Calibration Classes
+BQ27441_ID_CALIB_DATA = 104  # Data
+BQ27441_ID_CC_CAL = 105  # CC Cal
+BQ27441_ID_CURRENT = 107  # Current
+# Security Classes
+BQ27441_ID_CODES = 112  # Codes
+
+
+# OpConfig Register - Bit Definitions #
+
+# Bit positions of the OpConfig Register
+BQ27441_OPCONFIG_BIE = 1 << 13
+BQ27441_OPCONFIG_BI_PU_EN = 1 << 12
+BQ27441_OPCONFIG_GPIOPOL = 1 << 11
+BQ27441_OPCONFIG_SLEEP = 1 << 5
+BQ27441_OPCONFIG_RMFCC = 1 << 4
+BQ27441_OPCONFIG_BATLOWEN = 1 << 2
+BQ27441_OPCONFIG_TEMPS = 1 << 0
+
+BQ27441_I2C_TIMEOUT = 2000  # ms