TeraBee TeraRanger Evo 64px, User Manual, Page: 19 / 22

crc_value |= (ord(frame[index +
​
7
​
]) &
​
0x0F
​
)
crc_value = crc_value &
​
0xFFFFFFFF
crc32 = self.crc32(frame[:index])
if
​
crc32 == crc_value:
return
​ ​
True
else
​
:
print
​ ​
"Discarding current buffer because of bad checksum"
return
​ ​
False
A.2 Sample code
The python sample code provides with basic sensor functionality and communication,
including activating data output, reading data, sending commands and validating CRC
checksum. The python file of this sample code is available for download under “ ​ Download ​ ”
section of the TeraRanger Evo 64px product page.
#!/usr/bin/python
# -*- coding: utf-8 -*-
import
​
numpy
​
as
​
np
import
​
serial
import
​
crcmod.predefined
import
​
threading
class
​ ​
Evo_64px
​
(object):
def
​ ​
__init__
​
(self):
self.portname =
​
"/dev/ttyACM0"
self.baudrate =
​
115200
# Configure the serial connections (the parameters differs on the
device you are connecting to)
self.port = serial.Serial(
port=self.portname,
baudrate=self.baudrate,
parity=serial.PARITY_NONE,
stopbits=serial.STOPBITS_ONE,
bytesize=serial.EIGHTBITS
)
self.port.isOpen()
self.crc32 = crcmod.predefined.mkPredefinedCrcFun(
​
'crc-32-mpeg'
​
)
self.crc8 = crcmod.predefined.mkPredefinedCrcFun(
​
'crc-8'
​
)
self.serial_lock = threading.Lock()
Copyright
​ © ​ Terabee 2018
Terabee, 90 Rue Henri Fabre
01630, St Genis-Pouilly, France (next to CERN)
19/22