voicile script :
import smbus
import time
# Config Register (R/W)
_REG_CONFIG = 0x00
# SHUNT VOLTAGE REGISTER (R)
_REG_SHUNTVOLTAGE = 0x01
# BUS VOLTAGE REGISTER (R)
_REG_BUSVOLTAGE = 0x02
# POWER REGISTER (R)
_REG_POWER = 0x03
# CURRENT REGISTER (R)
_REG_CURRENT = 0x04
# CALIBRATION REGISTER (R/W)
_REG_CALIBRATION = 0x05
class BusVoltageRange:
"""Constants for ``bus_voltage_range``"""
RANGE_16V = 0x00 # set bus voltage range to 16V
RANGE_32V = 0x01 # set bus voltage range to 32V (default)
class Gain:
"""Constants for ``gain``"""
DIV_1_40MV = 0x00 # shunt prog. gain set to 1, 40 mV range
DIV_2_80MV = 0x01 # shunt prog. gain set to /2, 80 mV range
DIV_4_160MV = 0x02 # shunt prog. gain set to /4, 160 mV range
DIV_8_320MV = 0x03 # shunt prog. gain set to /8, 320 mV range
class ADCResolution:
"""Constants for ``bus_adc_resolution`` or ``shunt_adc_resolution``"""
ADCRES_9BIT_1S = 0x00 # 9bit, 1 sample, 84us
ADCRES_10BIT_1S = 0x01 # 10bit, 1 sample, 148us
ADCRES_11BIT_1S = 0x02 # 11 bit, 1 sample, 276us
ADCRES_12BIT_1S = 0x03 # 12 bit, 1 sample, 532us
ADCRES_12BIT_2S = 0x09 # 12 bit, 2 samples, 1.06ms
ADCRES_12BIT_4S = 0x0A # 12 bit, 4 samples, 2.13ms
ADCRES_12BIT_8S = 0x0B # 12bit, 8 samples, 4.26ms
ADCRES_12BIT_16S = 0x0C # 12bit, 16 samples, 8.51ms
ADCRES_12BIT_32S = 0x0D # 12bit, 32 samples, 17.02ms
ADCRES_12BIT_64S = 0x0E # 12bit, 64 samples, 34.05ms
ADCRES_12BIT_128S = 0x0F # 12bit, 128 samples, 68.10ms
class Mode:
"""Constants for ``mode``"""
POWERDOW = 0x00 # power down
SVOLT_TRIGGERED = 0x01 # shunt voltage triggered
BVOLT_TRIGGERED = 0x02 # bus voltage triggered
SANDBVOLT_TRIGGERED = 0x03 # shunt and bus voltage triggered
ADCOFF = 0x04 # ADC off
SVOLT_CONTINUOUS = 0x05 # shunt voltage continuous
BVOLT_CONTINUOUS = 0x06 # bus voltage continuous
SANDBVOLT_CONTINUOUS = 0x07 # shunt and bus voltage continuous
class INA219:
def __init__(self, i2c_bus=1, addr=0x40):
self.bus = smbus.SMBus(i2c_bus);
self.addr = addr
# Set chip to known config values to start
self._cal_value = 0
self._current_lsb = 0
self._power_lsb = 0
self.set_calibration_32V_2A()
def read(self,address):
data = self.bus.read_i2c_block_data(self.addr, address, 2)
return ((data[0] * 256 ) + data[1])
def write(self,address,data):
temp = [0,0]
temp[1] = data & 0xFF
temp[0] =(data & 0xFF00) >> 8
self.bus.write_i2c_block_data(self.addr,address,temp)
def set_calibration_32V_2A(self):
"""Configures to INA219 to be able to measure up to 32V and 2A of current. Counter
overflow occurs at 3.2A.
..note :: These calculations assume a 0.1 shunt ohm resistor is present
"""
# By default we use a pretty huge range for the input voltage,
# which probably isn't the most appropriate choice for system
# that don't use a lot of power. But all of the calculations
# are shown below if you want to change the settings. You will
# also need to change any relevant register settings, such as
# setting the VBUS_MAX to 16V instead of 32V, etc.
# VBUS_MAX = 32V (Assumes 32V, can also be set to 16V)
# VSHUNT_MAX = 0.32 (Assumes Gain 8, 320mV, can also be 0.16, 0.08, 0.04)
# RSHUNT = 0.1 (Resistor value in ohms)
# 1. Determine max possible current
# MaxPossible_I = VSHUNT_MAX / RSHUNT
# MaxPossible_I = 3.2A
# 2. Determine max expected current
# MaxExpected_I = 2.0A
# 3. Calculate possible range of LSBs (Min = 15-bit, Max = 12-bit)
# MinimumLSB = MaxExpected_I/32767
# MinimumLSB = 0.000061 (61uA per bit)
# MaximumLSB = MaxExpected_I/4096
# MaximumLSB = 0,000488 (488uA per bit)
# 4. Choose an LSB between the min and max values
# (Preferrably a roundish number close to MinLSB)
# CurrentLSB = 0.0001 (100uA per bit)
self._current_lsb = .1 # Current LSB = 100uA per bit
# 5. Compute the calibration register
# Cal = trunc (0.04096 / (Current_LSB * RSHUNT))
# Cal = 4096 (0x1000)
self._cal_value = 4096
# 6. Calculate the power LSB
# PowerLSB = 20 * CurrentLSB
# PowerLSB = 0.002 (2mW per bit)
self._power_lsb = .002 # Power LSB = 2mW per bit
# 7. Compute the maximum current and shunt voltage values before overflow
#
# Max_Current = Current_LSB * 32767
# Max_Current = 3.2767A before overflow
#
# If Max_Current > Max_Possible_I then
# Max_Current_Before_Overflow = MaxPossible_I
# Else
# Max_Current_Before_Overflow = Max_Current
# End If
#
# Max_ShuntVoltage = Max_Current_Before_Overflow * RSHUNT
# Max_ShuntVoltage = 0.32V
#
# If Max_ShuntVoltage >= VSHUNT_MAX
# Max_ShuntVoltage_Before_Overflow = VSHUNT_MAX
# Else
# Max_ShuntVoltage_Before_Overflow = Max_ShuntVoltage
# End If
# 8. Compute the Maximum Power
# MaximumPower = Max_Current_Before_Overflow * VBUS_MAX
# MaximumPower = 3.2 * 32V
# MaximumPower = 102.4W
# Set Calibration register to 'Cal' calculated above
self.write(_REG_CALIBRATION,self._cal_value)
# Set Config register to take into account the settings above
self.bus_voltage_range = BusVoltageRange.RANGE_32V
self.gain = Gain.DIV_8_320MV
self.bus_adc_resolution = ADCResolution.ADCRES_12BIT_32S
self.shunt_adc_resolution = ADCResolution.ADCRES_12BIT_32S
self.mode = Mode.SANDBVOLT_CONTINUOUS
self.config = self.bus_voltage_range << 13 | \
self.gain << 11 | \
self.bus_adc_resolution << 7 | \
self.shunt_adc_resolution << 3 | \
self.mode
self.write(_REG_CONFIG,self.config)
def getShuntVoltage_mV(self):
self.write(_REG_CALIBRATION,self._cal_value)
value = self.read(_REG_SHUNTVOLTAGE)
if value > 32767:
value -= 65535
return value * 0.01
def getBusVoltage_V(self):
self.write(_REG_CALIBRATION,self._cal_value)
self.read(_REG_BUSVOLTAGE)
return (self.read(_REG_BUSVOLTAGE) >> 3) * 0.004
def getCurrent_mA(self):
value = self.read(_REG_CURRENT)
if value > 32767:
value -= 65535
return value * self._current_lsb
def getPower_W(self):
self.write(_REG_CALIBRATION,self._cal_value)
value = self.read(_REG_POWER)
if value > 32767:
value -= 65535
return value * self._power_lsb
if __name__=='__main__':
# Create an INA219 instance.
ina219 = INA219(addr=0x42)
#while True:
bus_voltage = ina219.getBusVoltage_V() # voltage on V- (load side)
shunt_voltage = ina219.getShuntVoltage_mV() / 1000 # voltage between V+ and V- across the shunt
current = ina219.getCurrent_mA() # current in mA
power = ina219.getPower_W() # power in W
p = (bus_voltage - 6)/2.4*100
if(p > 100):p = 100
if(p < 0):p = 0
#print("{:6.1f}".format(bus_voltage))
#print(round(bus_voltage,1))
#print(',')
#print(round(power,1))
print("Load Voltage: {:6.3f} V".format(bus_voltage))
print("Current: {:9.6f} A".format(current/1000))
print("Power: {:6.3f} W".format(power))
print("Percent: {:3.1f}%".format(p))
