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sierralobo_ina230.py
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sierralobo_ina230.py
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"""
ina230.py
Texas Instruments INA230 I2C Power Monitor device Lib
* Author: Caden Hillis
"""
from micropython import const
from adafruit_bus_device.i2c_device import I2CDevice
from adafruit_register.i2c_bits import ROBits, RWBits
try:
from typing import Union
from busio import I2C
except ImportError:
pass
# Device Register Map
_CFG_REG = const(0x0)
# _SHUNT_VOLTAGE_REG = const(0x1)
_BUS_VOLT_REG = const(0x2)
# _POWER_REG = const(0x3)
_CUR_REG = const(0x4)
_CAL_REG = const(0x5)
# _MASK_EN_REG = const(0x6)
# _ALERT_LIMIT_REG = const(0x7)
# _DIE_ID_REG = const(0xff)
# Device Default Register Values
_CFG_DEFAULT = const(0x4127)
class INA230:
"""
class for controlling and reading INA230
not all regs and functionality implemented
"""
_cfg = RWBits(16, _CFG_REG, 0, register_width=2, lsb_first=False)
_bus_volt = ROBits(15, _BUS_VOLT_REG, 0, register_width=2, lsb_first=False)
_current = ROBits(16, _CUR_REG, 0, register_width=2, signed=True, lsb_first=False)
_cal = RWBits(16, _CAL_REG, 0, register_width=2, signed=False, lsb_first=False)
def __init__(
self,
i2c_bus: I2C,
addr: int = 0x70,
imax: Union[int, float] = 10,
rshunt: Union[int, float] = 10,
):
# imax is in amps
# rshunt is in mR
self.i2c_device = I2CDevice(i2c_bus, addr, probe=False)
if not self._cfg == _CFG_DEFAULT:
raise RuntimeError("[INA230.PY] INA230 not found")
self._imax = imax
self._rshunt = rshunt
self._lsb = self._imax / 2**15
self.calibrate()
@property
def bus_voltage(self) -> float:
"""bus voltage reading"""
return self._bus_volt * 0.00125
@property
def current(self) -> float:
"""current reading"""
cur = self._current
if self.cal != 0:
cur *= self._lsb
return cur
@property
def cal(self) -> int:
"""device calibration value"""
return self._cal
def calibrate(self):
"""calibaration the device"""
res = self._rshunt / 1000
cal = 0.00512 / (self._lsb * res)
cal = round(cal)
if cal >= 2**16:
cal = 0xFFFF
self._cal = cal