def searchTemplate(self):
"""
Search the finger characteristiccs in CharBuffer in database.
Return a tuple that contain the following information:
0: integer(2 bytes) The position number of found template.
1: integer(2 bytes) The accuracy score of found template.
@return tuple
"""
# CharBuffer1 and CharBuffer2 are the same in this case
charBufferNumber = 0x01
# Begin search at page 0x0000 for 0x00A3 (means 163) templates
positionStart = 0x0000
templatesCount = 0x00A3
packetPayload = (
FINGERPRINT_SEARCHTEMPLATE,
charBufferNumber,
utilities.rightShift(positionStart, 8),
utilities.rightShift(positionStart, 0),
utilities.rightShift(templatesCount, 8),
utilities.rightShift(templatesCount, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
# DEBUG: Found template
if (receivedPacketPayload[0] == FINGERPRINT_OK):
positionNumber = utilities.leftShift(receivedPacketPayload[1], 8)
positionNumber = positionNumber | utilities.leftShift(
receivedPacketPayload[2], 0)
accuracyScore = utilities.leftShift(receivedPacketPayload[3], 8)
accuracyScore = accuracyScore | utilities.leftShift(
receivedPacketPayload[4], 0)
return (positionNumber, accuracyScore)
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
# DEBUG: Did not found a matching template
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_NOTEMPLATEFOUND):
return (-1, -1)
else:
raise Exception('Unknown error')
def searchTemplate(self):
"""
Search the finger characteristiccs in CharBuffer in database.
Return a tuple that contain the following information:
0: integer(2 bytes) The position number of found template.
1: integer(2 bytes) The accuracy score of found template.
@return tuple
"""
## CharBuffer1 and CharBuffer2 are the same in this case
charBufferNumber = 0x01
## Begin search at index 0
positionStart = 0x0000
templatesCount = self.getStorageCapacity()
packetPayload = (
FINGERPRINT_SEARCHTEMPLATE,
charBufferNumber,
utilities.rightShift(positionStart, 8),
utilities.rightShift(positionStart, 0),
utilities.rightShift(templatesCount, 8),
utilities.rightShift(templatesCount, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
## DEBUG: Found template
if (receivedPacketPayload[0] == FINGERPRINT_OK):
positionNumber = utilities.leftShift(receivedPacketPayload[1], 8)
positionNumber = positionNumber | utilities.leftShift(
receivedPacketPayload[2], 0)
accuracyScore = utilities.leftShift(receivedPacketPayload[3], 8)
accuracyScore = accuracyScore | utilities.leftShift(
receivedPacketPayload[4], 0)
return (positionNumber, accuracyScore)
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
## DEBUG: Did not found a matching template
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_NOTEMPLATEFOUND):
return (-1, -1)
else:
raise Exception('Unknown error')
def loadTemplate(self, positionNumber, charBufferNumber=0x01):
"""
Load an existing template specified by position number to specified CharBuffer.
@param integer(2 bytes) positionNumber
@param integer(1 byte) charBufferNumber
@return boolean
"""
if (positionNumber < 0x0000
or positionNumber >= self.getStorageCapacity()):
raise ValueError('The given position number is invalid!')
if (charBufferNumber != 0x01 and charBufferNumber != 0x02):
raise ValueError('The given charbuffer number is invalid!')
packetPayload = (
FINGERPRINT_LOADTEMPLATE,
charBufferNumber,
utilities.rightShift(positionNumber, 8),
utilities.rightShift(positionNumber, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
## DEBUG: Template loaded successful
if (receivedPacketPayload[0] == FINGERPRINT_OK):
return True
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_LOADTEMPLATE):
raise Exception('The template could not be read')
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_INVALIDPOSITION):
raise Exception('Could not load template from that position')
else:
raise Exception('Unknown error')
def storeTemplate(self, positionNumber, charBufferNumber=0x01):
"""
Save a template from the specified CharBuffer to the given position number.
@param integer(2 bytes) positionNumber
@param integer(1 byte) charBufferNumber
@return boolean
"""
if (positionNumber < 0x0000 or positionNumber > 0x00A3):
raise ValueError('The given position number is invalid!')
if (charBufferNumber != 0x01 and charBufferNumber != 0x02):
raise ValueError('The given charbuffer number is invalid!')
packetPayload = (
FINGERPRINT_STORETEMPLATE,
charBufferNumber,
utilities.rightShift(positionNumber, 8),
utilities.rightShift(positionNumber, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
## DEBUG: Template stored successful
if (receivedPacketPayload[0] == FINGERPRINT_OK):
return True
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_INVALIDPOSITION):
raise Exception('Could not store template in that position')
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_FLASH):
raise Exception('Error writing to flash')
else:
raise Exception('Unknown error')
def loadTemplate(self, positionNumber, charBufferNumber = 0x01):
"""
Load an existing template specified by position number to specified CharBuffer.
@param integer(2 bytes) positionNumber
@param integer(1 byte) charBufferNumber
@return boolean
"""
if ( positionNumber < 0x0000 or positionNumber > 0x0400 ):
raise ValueError('The given position number is invalid!')
if ( charBufferNumber != 0x01 and charBufferNumber != 0x02 ):
raise ValueError('The given charbuffer number is invalid!')
packetPayload = (
FINGERPRINT_LOADTEMPLATE,
charBufferNumber,
utilities.rightShift(positionNumber, 8),
utilities.rightShift(positionNumber, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if ( receivedPacketType != FINGERPRINT_ACKPACKET ):
raise Exception('The received packet is no ack packet!')
## DEBUG: Template loaded successful
if ( receivedPacketPayload[0] == FINGERPRINT_OK ):
return True
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION ):
raise Exception('Communication error')
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_LOADTEMPLATE ):
raise Exception('The template could not be read')
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_INVALIDPOSITION ):
raise Exception('Could not load template from that position')
else:
raise Exception('Unknown error')
def deleteTemplate(self, positionNumber):
"""
Delete one template from fingerprint database.
@param integer(2 bytes) positionNumber
@return boolean
"""
if (positionNumber < 0x0000
or positionNumber >= self.getStorageCapacity()):
raise ValueError('The given position number is invalid!')
## Delete only one template
count = 0x0001
packetPayload = (
FINGERPRINT_DELETETEMPLATE,
utilities.rightShift(positionNumber, 8),
utilities.rightShift(positionNumber, 0),
utilities.rightShift(count, 8),
utilities.rightShift(count, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
## DEBUG: Template deleted successful
if (receivedPacketPayload[0] == FINGERPRINT_OK):
return True
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
## DEBUG: Could not delete template
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_DELETETEMPLATE):
return False
else:
raise Exception('Unknown error')
def deleteTemplate(self, positionNumber):
"""
Delete one template from fingerprint database.
@param integer(2 bytes) positionNumber
@return boolean
"""
if ( positionNumber < 0x0000 or positionNumber > 0x0400 ):
raise ValueError('The given position number is invalid!')
## Delete only one template
count = 0x0001
packetPayload = (
FINGERPRINT_DELETETEMPLATE,
utilities.rightShift(positionNumber, 8),
utilities.rightShift(positionNumber, 0),
utilities.rightShift(count, 8),
utilities.rightShift(count, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if ( receivedPacketType != FINGERPRINT_ACKPACKET ):
raise Exception('The received packet is no ack packet!')
## DEBUG: Template deleted successful
if ( receivedPacketPayload[0] == FINGERPRINT_OK ):
return True
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION ):
raise Exception('Communication error')
## DEBUG: Could not delete template
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_DELETETEMPLATE ):
return False
else:
raise Exception('Unknown error')
def setPassword(self, newPassword):
"""
Set the password of the sensor.
@param integer(4 bytes) newPassword
@return boolean
"""
# Validate the password (maximum 4 bytes)
if (newPassword < 0x00000000 or newPassword > 0xFFFFFFFF):
raise ValueError('The given password is invalid!')
packetPayload = (
FINGERPRINT_SETPASSWORD,
utilities.rightShift(newPassword, 24),
utilities.rightShift(newPassword, 16),
utilities.rightShift(newPassword, 8),
utilities.rightShift(newPassword, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
# DEBUG: Password set was successful
if (receivedPacketPayload[0] == FINGERPRINT_OK):
return True
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
else:
raise Exception('Unknown error')
def setAddress(self, newAddress):
"""
Set the module address of the sensor.
@param integer(4 bytes) newAddress
@return boolean
"""
## Validate the address (maximum 4 bytes)
if (newAddress < 0x00000000 or newAddress > 0xFFFFFFFF):
raise ValueError('The given address is invalid!')
packetPayload = (
FINGERPRINT_SETADDRESS,
utilities.rightShift(newAddress, 24),
utilities.rightShift(newAddress, 16),
utilities.rightShift(newAddress, 8),
utilities.rightShift(newAddress, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
## DEBUG: Address set was successful
if (receivedPacketPayload[0] == FINGERPRINT_OK):
return True
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
else:
raise Exception('Unknown error')
def setAddress(self, newAddress):
"""
Set the module address of the sensor.
@param integer(4 bytes) newAddress
@return boolean
"""
## Validate the address (maximum 4 bytes)
if ( newAddress < 0x00000000 or newAddress > 0xFFFFFFFF ):
raise ValueError('The given address is invalid!')
packetPayload = (
FINGERPRINT_SETADDRESS,
utilities.rightShift(newAddress, 24),
utilities.rightShift(newAddress, 16),
utilities.rightShift(newAddress, 8),
utilities.rightShift(newAddress, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if ( receivedPacketType != FINGERPRINT_ACKPACKET ):
raise Exception('The received packet is no ack packet!')
## DEBUG: Address set was successful
if ( receivedPacketPayload[0] == FINGERPRINT_OK ):
return True
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION ):
raise Exception('Communication error')
else:
raise Exception('Unknown error')
def verifyPassword(self):
"""
Verifie password of the fingerprint sensor.
@return boolean
"""
packetPayload = (
FINGERPRINT_VERIFYPASSWORD,
utilities.rightShift(self.__password, 24),
utilities.rightShift(self.__password, 16),
utilities.rightShift(self.__password, 8),
utilities.rightShift(self.__password, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
## DEBUG: Sensor password is correct
if (receivedPacketPayload[0] == FINGERPRINT_OK):
return True
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
## DEBUG: Sensor password is wrong
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_WRONGPASSWORD):
return False
else:
raise Exception('Unknown error')
def verifyPassword(self):
"""
Verifie password of the fingerprint sensor.
@return boolean
"""
packetPayload = (
FINGERPRINT_VERIFYPASSWORD,
utilities.rightShift(self.__password, 24),
utilities.rightShift(self.__password, 16),
utilities.rightShift(self.__password, 8),
utilities.rightShift(self.__password, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if ( receivedPacketType != FINGERPRINT_ACKPACKET ):
raise Exception('The received packet is no ack packet!')
## DEBUG: Sensor password is correct
if ( receivedPacketPayload[0] == FINGERPRINT_OK ):
return True
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION ):
raise Exception('Communication error')
## DEBUG: Sensor password is wrong
elif ( receivedPacketPayload[0] == FINGERPRINT_ERROR_WRONGPASSWORD ):
return False
else:
raise Exception('Unknown error')
def __writePacket(self, packetType, packetPayload):
"""
Send a packet to fingerprint sensor.
@param integer(1 byte) packetType
@param tuple packetPayload
@return void
"""
## Write header (one byte at once)
self.__serial.write(utilities.byteToString(utilities.rightShift(FINGERPRINT_STARTCODE, 8)))
self.__serial.write(utilities.byteToString(utilities.rightShift(FINGERPRINT_STARTCODE, 0)))
self.__serial.write(utilities.byteToString(utilities.rightShift(self.__address, 24)))
self.__serial.write(utilities.byteToString(utilities.rightShift(self.__address, 16)))
self.__serial.write(utilities.byteToString(utilities.rightShift(self.__address, 8)))
self.__serial.write(utilities.byteToString(utilities.rightShift(self.__address, 0)))
self.__serial.write(utilities.byteToString(packetType))
## The packet length = package payload (n bytes) + checksum (2 bytes)
packetLength = len(packetPayload) + 2
self.__serial.write(utilities.byteToString(utilities.rightShift(packetLength, 8)))
self.__serial.write(utilities.byteToString(utilities.rightShift(packetLength, 0)))
## The packet checksum = packet type (1 byte) + packet length (2 bytes) + payload (n bytes)
packetChecksum = packetType + utilities.rightShift(packetLength, 8) + utilities.rightShift(packetLength, 0)
## Write payload
for i in range(0, len(packetPayload)):
self.__serial.write(utilities.byteToString(packetPayload[i]))
packetChecksum += packetPayload[i]
## Write checksum (2 bytes)
self.__serial.write(utilities.byteToString(utilities.rightShift(packetChecksum, 8)))
self.__serial.write(utilities.byteToString(utilities.rightShift(packetChecksum, 0)))
def __readPacket(self):
"""
Receive a packet from fingerprint sensor.
Return a tuple that contain the following information:
0: integer(1 byte) The packet type.
1: integer(n bytes) The packet payload.
@return tuple
"""
receivedPacketData = []
i = 0
while ( True ):
## Read one byte
receivedFragment = self.__serial.read()
if ( len(receivedFragment) != 0 ):
receivedFragment = utilities.stringToByte(receivedFragment)
## print 'Received packet fragment = ' + hex(receivedFragment)
## Insert byte if packet seems valid
receivedPacketData.insert(i, receivedFragment)
i += 1
## Packet could be complete (the minimal packet size is 12 bytes)
if ( i >= 12 ):
## Check the packet header
if ( receivedPacketData[0] != utilities.rightShift(FINGERPRINT_STARTCODE, 8) or receivedPacketData[1] != utilities.rightShift(FINGERPRINT_STARTCODE, 0) ):
raise Exception('The received packet do not begin with a valid header!')
## Calculate packet payload length (combine the 2 length bytes)
packetPayloadLength = utilities.leftShift(receivedPacketData[7], 8)
packetPayloadLength = packetPayloadLength | utilities.leftShift(receivedPacketData[8], 0)
## Check if the packet is still fully received
## Condition: index counter < packet payload length + packet frame
if ( i < packetPayloadLength + 9 ):
continue
## At this point the packet should be fully received
packetType = receivedPacketData[6]
## Calculate checksum:
## checksum = packet type (1 byte) + packet length (2 bytes) + packet payload (n bytes)
packetChecksum = packetType + receivedPacketData[7] + receivedPacketData[8]
packetPayload = []
## Collect package payload (ignore the last 2 checksum bytes)
for j in range(9, 9 + packetPayloadLength - 2):
packetPayload.append(receivedPacketData[j])
packetChecksum += receivedPacketData[j]
## Calculate full checksum of the 2 separate checksum bytes
receivedChecksum = utilities.leftShift(receivedPacketData[i - 2], 8)
receivedChecksum = receivedChecksum | utilities.leftShift(receivedPacketData[i - 1], 0)
if ( receivedChecksum != packetChecksum ):
raise Exception('The received packet is corrupted (the checksum is wrong)!')
return (packetType, packetPayload)
def storeTemplate(self, positionNumber=-1, charBufferNumber=0x01):
"""
Save a template from the specified CharBuffer to the given position number.
@param integer(2 bytes) positionNumber
@param integer(1 byte) charBufferNumber
@return integer
"""
## Find a free index
if (positionNumber == -1):
for page in range(0, 4):
## Free index found?
if (positionNumber >= 0):
break
templateIndex = self.getTemplateIndex(page)
for i in range(0, len(templateIndex)):
## Index not used?
if (templateIndex[i] == False):
positionNumber = (len(templateIndex) * page) + i
break
if (positionNumber < 0x0000
or positionNumber >= self.getStorageCapacity()):
raise ValueError('The given position number is invalid!')
if (charBufferNumber != 0x01 and charBufferNumber != 0x02):
raise ValueError('The given charbuffer number is invalid!')
packetPayload = (
FINGERPRINT_STORETEMPLATE,
charBufferNumber,
utilities.rightShift(positionNumber, 8),
utilities.rightShift(positionNumber, 0),
)
self.__writePacket(FINGERPRINT_COMMANDPACKET, packetPayload)
receivedPacket = self.__readPacket()
receivedPacketType = receivedPacket[0]
receivedPacketPayload = receivedPacket[1]
if (receivedPacketType != FINGERPRINT_ACKPACKET):
raise Exception('The received packet is no ack packet!')
## DEBUG: Template stored successful
if (receivedPacketPayload[0] == FINGERPRINT_OK):
return positionNumber
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_COMMUNICATION):
raise Exception('Communication error')
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_INVALIDPOSITION):
raise Exception('Could not store template in that position')
elif (receivedPacketPayload[0] == FINGERPRINT_ERROR_FLASH):
raise Exception('Error writing to flash')
else:
raise Exception('Unknown error')
def __readPacket(self):
"""
Receive a packet from fingerprint sensor.
Return a tuple that contain the following information:
0: integer(1 byte) The packet type.
1: integer(n bytes) The packet payload.
@return tuple
"""
receivedPacketData = []
i = 0
while (True):
## Read one byte
receivedFragment = self.__serial.read()
if (len(receivedFragment) != 0):
receivedFragment = utilities.stringToByte(receivedFragment)
## print 'Received packet fragment = ' + hex(receivedFragment)
## Insert byte if packet seems valid
receivedPacketData.insert(i, receivedFragment)
i += 1
## Packet could be complete (the minimal packet size is 12 bytes)
if (i >= 12):
## Check the packet header
if (receivedPacketData[0] != utilities.rightShift(
FINGERPRINT_STARTCODE, 8)
or receivedPacketData[1] != utilities.rightShift(
FINGERPRINT_STARTCODE, 0)):
raise Exception(
'The received packet do not begin with a valid header!'
)
## Calculate packet payload length (combine the 2 length bytes)
packetPayloadLength = utilities.leftShift(
receivedPacketData[7], 8)
packetPayloadLength = packetPayloadLength | utilities.leftShift(
receivedPacketData[8], 0)
## Check if the packet is still fully received
## Condition: index counter < packet payload length + packet frame
if (i < packetPayloadLength + 9):
continue
## At this point the packet should be fully received
packetType = receivedPacketData[6]
## Calculate checksum:
## checksum = packet type (1 byte) + packet length (2 bytes) + packet payload (n bytes)
packetChecksum = packetType + receivedPacketData[
7] + receivedPacketData[8]
packetPayload = []
## Collect package payload (ignore the last 2 checksum bytes)
for j in range(9, 9 + packetPayloadLength - 2):
packetPayload.append(receivedPacketData[j])
packetChecksum += receivedPacketData[j]
## Calculate full checksum of the 2 separate checksum bytes
receivedChecksum = utilities.leftShift(
receivedPacketData[i - 2], 8)
receivedChecksum = receivedChecksum | utilities.leftShift(
receivedPacketData[i - 1], 0)
if (receivedChecksum != packetChecksum):
raise Exception(
'The received packet is corrupted (the checksum is wrong)!'
)
return (packetType, packetPayload)
def __writePacket(self, packetType, packetPayload):
"""
Send a packet to fingerprint sensor.
@param integer(1 byte) packetType
@param tuple packetPayload
@return void
"""
## Write header (one byte at once)
self.__serial.write(
utilities.byteToString(
utilities.rightShift(FINGERPRINT_STARTCODE, 8)))
self.__serial.write(
utilities.byteToString(
utilities.rightShift(FINGERPRINT_STARTCODE, 0)))
self.__serial.write(
utilities.byteToString(utilities.rightShift(self.__address, 24)))
self.__serial.write(
utilities.byteToString(utilities.rightShift(self.__address, 16)))
self.__serial.write(
utilities.byteToString(utilities.rightShift(self.__address, 8)))
self.__serial.write(
utilities.byteToString(utilities.rightShift(self.__address, 0)))
self.__serial.write(utilities.byteToString(packetType))
## The packet length = package payload (n bytes) + checksum (2 bytes)
packetLength = len(packetPayload) + 2
self.__serial.write(
utilities.byteToString(utilities.rightShift(packetLength, 8)))
self.__serial.write(
utilities.byteToString(utilities.rightShift(packetLength, 0)))
## The packet checksum = packet type (1 byte) + packet length (2 bytes) + payload (n bytes)
packetChecksum = packetType + utilities.rightShift(
packetLength, 8) + utilities.rightShift(packetLength, 0)
## Write payload
for i in range(0, len(packetPayload)):
self.__serial.write(utilities.byteToString(packetPayload[i]))
packetChecksum += packetPayload[i]
## Write checksum (2 bytes)
self.__serial.write(
utilities.byteToString(utilities.rightShift(packetChecksum, 8)))
self.__serial.write(
utilities.byteToString(utilities.rightShift(packetChecksum, 0)))
