def check_safety_level_1(self):
"""
Method returns True if everything OK. False if the level 1 limits have been exceeded.
"""
try:
c_ovp = self.pack_variables[
'cv_max'] > settings.BATTERY_CELL_OVP_LEVEL_1
c_uvp = self.pack_variables[
'cv_min'] < settings.BATTERY_CELL_UVP_LEVEL_1
if c_uvp:
log_battery.info('Cell undervoltage, level 1 on port: %s',
self.com_port)
self.pack_variables['is_cell_undervoltage_level_1'] = True
self.pack_variables['is_not_safe_level_1'] = True
return False
elif c_ovp:
log_battery.info('Cell overvoltage, level 1 on port: %s',
self.com_port)
self.pack_variables['is_cell_overvoltage_level_1'] = True
self.pack_variables['is_not_safe_level_1'] = True
return False
else:
return True
except Exception as err:
log_battery.exception(
'Exception in checking cell safety level 1 on port %s. Exception is: %s',
self.com_port, err)
return False
def get_pack_status(self):
"""
Method gets the status message from the battery pack. It populates self.status with the reply
"""
try:
message = b'\x57\x01\x34\x40\x01\x00\x00\x41\x03'
self.serial_handle.write(message)
time.sleep(0.1)
reply = self.serial_handle.read(10)
message = b'\x54\x41\x3E' #this matches the length of the message read
self.serial_handle.reset_input_buffer()
self.serial_handle.write(message)
time.sleep(0.1)
self.status_message = self.serial_handle.read(100)
crc = 0
# what is the hell? is that a dict or a list?
crc_received = int.from_bytes(
{self.status_message[-2], self.status_message[-1]},
byteorder='little')
for i in range(60):
crc = crc + self.status_message[i]
if crc == crc_received:
return True
else:
log_battery.info(
'Status message CRC failed for battery on port %s.',
self.com_port)
return False
except Exception as err:
log_battery.exception(
'Could not refresh pack values on port %s. Reason: %s.',
self.com_port, err)
return False
def check_safety_level_2(self):
"""
Method return True if everything OK. False if a test stop trigger should be issued.
"""
if time.time() - self.start_timestamp >= 20:
return False
return True
try:
c_ovp = self.pack_variables[
'cv_max'] > settings.BATTERY_CELL_OVP_LEVEL_2
c_uvp = self.pack_variables[
'cv_min'] < settings.BATTERY_CELL_UVP_LEVEL_2
ocp = self.pack_variables['dc_current'] > settings.BATTERY_OCP
ovt_mosfet = self.pack_variables[
'mosfet_temp'] > settings.MOSFETS_OVERTEMPERATURE
ovt_cells = self.pack_variables[
'pack_temp'] > settings.CELLS_OVERTEMPERATURE
if c_ovp:
log_battery.info('Cell over-voltage, level 2. Port: %s',
self.com_port)
self.pack_variables['is_cell_overvoltage_level_2'] = True
self.pack_variables['is_not_safe_level_2'] = True
return False
elif c_uvp:
log_battery.info('Cell under-voltage, level 2. Port: %s',
self.com_port)
self.pack_variables['is_cell_undervoltage_level_2'] = True
self.pack_variables['is_not_safe_level_2'] = True
return False
elif ocp:
log_battery.info('Battery over-current. Port: %s',
self.com_port)
self.pack_variables['is_pack_overcurrent'] = True
self.pack_variables['is_not_safe_level_2'] = True
return False
elif ovt_mosfet:
log_battery.info('Over-temperature (mosfets) on port: %s',
self.com_port)
self.pack_variables['is_overtemperature_mosfets'] = True
self.pack_variables['is_not_safe_level_2'] = True
return False
elif ovt_cells:
log_battery.info('Over-temperature (mosfets) on port: %s',
self.com_port)
self.pack_variables['is_overtemperature_cells'] = True
self.pack_variables['is_not_safe_level_2'] = True
return False
else:
return True
except Exception as err:
log_battery.exception(
'Error in checking safety level 2 on port %s. Exception is: %s',
self.com_port, err)
return False
def close_coms(self):
"""
Closes resources for battery serial
"""
try:
self.serial_handle.close()
log_battery.info('Closed battery port %s.', self.com_port)
return True
except Exception as err:
log_battery.exception('Could not close battery port %s because %s',
self.com_port, err)
def clear_level_1_error_flag(self):
"""
Method clears the level_1_error_flag
"""
try:
self.pack_variables['is_not_safe_level_1'] = False
return True
except Exception as err:
log_battery.exception(
'Unable to clear error fral level 1 in batt on port %s. Reason is %s',
self.com_port, err)
return False
def __init__(self, com_port):
self.status_message = b''
self.pack_variables = {
'serial_number': 0,
'cv_1': 0,
'cv_2': 0,
'cv_3': 0,
'cv_4': 0,
'cv_5': 0,
'cv_6': 0,
'cv_7': 0,
'cv_8': 0,
'cv_9': 0,
'cv_max': 0,
'cv_min': 0,
'mosfet_temp': 0,
'pack_temp': 0,
'dc_current': 0,
'is_cell_overvoltage_level_1': False,
'is_cell_overvoltage_level_2': False,
'is_cell_undervoltage_level_1': False,
'is_cell_undervoltage_level_2': False,
'is_not_safe_level_1': False,
'is_not_safe_level_2': False,
'is_pack_overcurrent': False,
'is_overtemperature_mosfets': False,
'is_overtemperature_cells': False,
'is_on': False,
'last_status_update': time.time()
}
self.start_timestamp = time.time()
self.com_port = com_port
try:
self.serial_handle = serial.Serial()
self.serial_handle.port = self.com_port
self.serial_handle.baudrate = 19200
self.serial_handle.timeout = 0.1
self.serial_handle.parity = 'N'
self.serial_handle.setDTR(False)
self.serial_handle.bytesize = serial.EIGHTBITS
self.serial_handle.stopbits = serial.STOPBITS_TWO
self.serial_handle.open()
except Exception as err:
log_battery.exception(
'Cannot open comms to battery on port %s because of the following error: %s',
self.com_port, err)
def get_pack_current(self):
"""
Extract the pack current out of the battery message reply (get_Status command). Updates self.dc_current
input: none
output: True if successful. False otherwise
"""
try:
temp_variable = struct.unpack('<f', self.status_message[50:54])
self.pack_variables['dc_current'] = "{0:.3f}".format(
temp_variable[0])
return True
except Exception as err:
log_battery.exception(
'Cannot refresh pack current value for batt on port %s. Reason is: %s.',
self.com_port, err)
return False
def get_temperatures(self):
"""
method extracts the temperature readouts from self.status and populates mosfet and pack temperature readings
"""
try:
mosfet_temp = struct.unpack('<f', self.status_message[6:10])
pack_temp = struct.unpack('<f', self.status_message[10:14])
self.pack_variables['mosfet_temp'] = "{0:.3f}".format(
mosfet_temp[0])
self.pack_variables['pack_temp'] = "{0:.3f}".format(pack_temp[0])
return True
except Exception as err:
log_battery.exception(
'Could not refresh temperature values for pack on port %s. Exception is: %s.',
self.com_port, err)
return False
def turn_pack_on(self, com_port_handle):
"""
This method turns the pack on. Note: function needs to be send every 10 sec minimum to maintain pack on.
input: com_port handler
output: True if successful. False otherwise
"""
try:
test = b'\x57\x01\x35\x40\x04\x01\x03\x00\x48\x03'
self.serial_handle.write(test)
time.sleep(0.01)
test = b'\x57\x01\x30\x41\x20\x03'
self.serial_handle.write(test)
time.sleep(0.01)
log_battery.info('Pack on port %s has been turned on.',
self.com_port)
return True
except Exception as err:
log_battery.exception(
'Error when turning pack on port: %s. Pack serial number: %s',
self.com_port, self.serial_number)
return False
def configure_USB_ISS(self):
"""
This function will take care of configuring the USB-> I2C bridge.
"""
try:
message = b'\x5A\x01'
self.serial_handle.write(message)
time.sleep(0.5)
self.serial_handle.read(10)
# Setting the mode
I2C_mode_message = b'\x5A\x02\x60\x04'
self.serial_handle.write(I2C_mode_message)
time.sleep(0.5)
self.serial_handle.read(10)
log_battery.info('Configure the ISS adapter for com: %s',
self.com_port)
return True
except Exception as err:
log_battery.exception(
'Error when configuring the USB ISS bridge on com %s. Error is: %s',
self.com_port, err)
return False
def update_values(self):
"""
Call this function to update all the model attributes that are read from the battery.
"""
try:
if not self.get_pack_status():
log_battery.info(
'Asked for new status but failed. Either CRC or exception. Port: %s',
self.com_port)
return False
self.get_serial_number()
self.get_pack_current()
self.get_cell_voltages()
self.get_temperatures()
log_battery.info('Pack values updated. Pack serial number:')
# log_battery.info('Pack cell voltages: %s, %s, %s, %s, %s, %s, %s, %s, %s', self.cv_1,
# self.cv_2, self.cv_3, self.cv_4, self.cv_5, self.cv_6, self.cv_7, self.cv_8, self.cv_9)
self.pack_variables['last_status_update'] = time.time()
return True
except Exception as err:
log_battery.exception(
'Error encountered while updating pack values. Exception is: %s',
err)
return False
def get_cell_voltages(self):
"""
Function gets cell voltages out of self.status and populates cv1 -> cv9 as well as cv_max and cv_min
"""
try:
data = self.status_message
C1 = (struct.unpack(
'>f',
struct.pack("B", data[17]) + struct.pack("B", data[16]) +
struct.pack("B", data[15]) + struct.pack("B", data[14])))
C2 = (struct.unpack(
'>f',
struct.pack("B", data[21]) + struct.pack("B", data[20]) +
struct.pack("B", data[19]) + struct.pack("B", data[18])))
C3 = (struct.unpack(
'>f',
struct.pack("B", data[25]) + struct.pack("B", data[24]) +
struct.pack("B", data[23]) + struct.pack("B", data[22])))
C4 = (struct.unpack(
'>f',
struct.pack("B", data[29]) + struct.pack("B", data[28]) +
struct.pack("B", data[27]) + struct.pack("B", data[26])))
C5 = (struct.unpack(
'>f',
struct.pack("B", data[33]) + struct.pack("B", data[32]) +
struct.pack("B", data[31]) + struct.pack("B", data[30])))
C6 = (struct.unpack(
'>f',
struct.pack("B", data[37]) + struct.pack("B", data[36]) +
struct.pack("B", data[35]) + struct.pack("B", data[34])))
C7 = (struct.unpack(
'>f',
struct.pack("B", data[41]) + struct.pack("B", data[40]) +
struct.pack("B", data[39]) + struct.pack("B", data[38])))
C8 = (struct.unpack(
'>f',
struct.pack("B", data[45]) + struct.pack("B", data[44]) +
struct.pack("B", data[43]) + struct.pack("B", data[42])))
C9 = (struct.unpack(
'>f',
struct.pack("B", data[49]) + struct.pack("B", data[48]) +
struct.pack("B", data[47]) + struct.pack("B", data[46])))
self.pack_variables['cv_1'] = "{0:.3f}".format(C1[0])
self.pack_variables['cv_2'] = "{0:.3f}".format(C2[0])
self.pack_variables['cv_3'] = "{0:.3f}".format(C3[0])
self.pack_variables['cv_4'] = "{0:.3f}".format(C4[0])
self.pack_variables['cv_5'] = "{0:.3f}".format(C5[0])
self.pack_variables['cv_6'] = "{0:.3f}".format(C6[0])
self.pack_variables['cv_7'] = "{0:.3f}".format(C7[0])
self.pack_variables['cv_8'] = "{0:.3f}".format(C8[0])
self.pack_variables['cv_9'] = "{0:.3f}".format(C9[0])
self.pack_variables['cv_min'] = min([
self.pack_variables['cv_1'], self.pack_variables['cv_2'],
self.pack_variables['cv_3'], self.pack_variables['cv_4'],
self.pack_variables['cv_5'], self.pack_variables['cv_6'],
self.pack_variables['cv_7'], self.pack_variables['cv_8'],
self.pack_variables['cv_9']
])
self.pack_variables['cv_max'] = max([
self.pack_variables['cv_1'], self.pack_variables['cv_2'],
self.pack_variables['cv_3'], self.pack_variables['cv_4'],
self.pack_variables['cv_5'], self.pack_variables['cv_6'],
self.pack_variables['cv_7'], self.pack_variables['cv_8'],
self.pack_variables['cv_9']
])
return True
except Exception as err:
log_battery.exception(
'Could not refresh cell voltages on port %s. Reason: %s.',
self.com_port, err)
return False
