I'm running xillinux (more or less ubuntu 12.04) on zedboard. Zedboard combines arm with fpga.
Now have written a python script wich reads data from a device driver (/dev/xillybus_read_32).
Now i know the data i recieve is complete and correct (i used a prewritten program that stored al the data in a dumpfile, i splitted this dumpfile in frames and cheched if the content was correct ( every frame contains an addition, so easy to check).
Now when i try to recieve data from the device driver with the following python script:
#Read data
#Framesize
CONST_FRAMESIZE = (640*480*16)/8
#Info
frame_true = 0
frame_false = 0
#Open file
pipe_in = open("/dev/xillybus_read_32","r")
count = 0
count_false = 0
for z in xrange(1000):
frame = "frame" + str(count) + ".raw"
pipe_out = open(frame,"wb")
for r in xrange(CONST_FRAMESIZE/4):
value = pipe_in.read(4)
pipe_out.write(value)
pipe_out.close()
#Compare goldendata with frame
if filecmp.cmp("goldendata",frame):
frame_true = frame_true + 1
if count >= 1:
os.remove(frame_last)
frame_last = frame
else:
print "frame_true:", frame_true
pipe_in.close()
sys.exit()
#frame_false = frame_false + 1
#os.remove(frame)
count = count + 1;
#Close opend file
pipe_in.close()
I recieve all the data but, sometimes i get my 32 bit words 2 times. It's like it sometimes reads the 32bit word twice. I doesn't lose data, it just reads a 32 bit sometimes 2 times. Very strange.
Thnx
Related
My program is search the upper and lower value from .txt file according to that input value.
def find_closer():
file = 'C:/.../CariCBABaru.txt'
data = np.loadtxt(file)
x, y = data[:,0], data[:,1]
print(y)
for k in range(len(spasi_baru)):
a = y #[0, 20.28000631, 49.43579604, 78.59158576, 107.7473755, 136.9031652, 166.0589549,
176.5645474, 195.2147447]
b = spasi_baru[k]
# diff_list = []
diff_dict = OrderedDict()
if b in a:
b = input("Number already exists, please enter another number ")
else:
for x in a:
diff = x - b
if diff < 0:
# diff_list.append(diff*(-1))
diff_dict[x] = diff*(-1)
else:
# diff_list.append(diff)
diff_dict[x] = diff
#print("diff_dict", diff_dict)
# print(diff_dict[9])
sort_dict_keys = sorted(diff_dict.keys())
#print(sort_dict_keys)
closer_less = 0
closer_more = 0
#cl = []
#cm = []
for closer in sort_dict_keys:
if closer < b:
closer_less = closer
else:
closer_more = closer
break
#cl.append(closer_less == len(spasi_baru) - 1)
#cm.append(closer_more == len(spasi_baru) - 1)
print(spasi_baru[k],": lower value=", closer_less, "and upper
value =", closer_more)
data = open('C:/.../Batas.txt','w')
text = "Spasi baru:{spasi_baru}, File: {closer_less}, line:{closer_more}".format(spasi_baru=spasi_baru[k], closer_less=closer_less, closer_more=closer_more)
data.write(text)
data.close()
print(spasi_baru[k],": lower value=", closer_less, "and upper value =", closer_more)
find_closer()
The results image is here 1
Then, i want to write these results to file (txt/csv no problem) into rows and columns sequence. But the problem that i have, the file contain just one row or written the last value output in terminal like below,
Spasi baru:400, File: 399.3052727, line: 415.037138
any suggestions to help fix my problem please? I stuck in a several hours to tried any different code algorithms. I'm using Python 3.7
The best solution is to use w+ or a+ mode when you're trying to append into the same test file.
Instead of doing this:
data = open('C:/.../Batas.txt','w')
Do this:
data = open('C:/.../Batas.txt','w+')
or
data = open('C:/.../Batas.txt','a+')
The reason is because you are overwriting the same file over and over inside the loop, so it will keep just the last interaction. Look for ways to save files without overwriting them.
‘r’ – Read mode which is used when the file is only being read
‘w’ – Write mode which is used to edit and write new information to the file (any existing files with the same name will be erased when this mode is activated)
‘a’ – Appending mode, which is used to add new data to the end of the file; that is new information is automatically amended to the end
‘r+’ – Special read and write mode, which is used to handle both actions when working with a file
I am reading a raw disk image using python 3. My task is to retrieve (carve) jpgs as individual files from the disk image. As I know header pattern (\xd8\xff\xe0 or \xd8\xff\xe1) of jpg. I want to know where I get this while reading file.
fobj = open('carve.dd', 'rb')
data = fobj.read(32)
while data != '':
head_loc = findheader(data)
print(head_loc)
data = fobj.read(32)
def findheader(data) : # to find header in each 32 bytes of data of raw disk image
for i in range(0, len(data) - 3) :
if data[i] == b'\xff' :
if data[i+1:i+4] == b'\xd8\xff\xe0' or data[i+1:i+4] == b'\xd8\xff\xe1' :
return i
return -1
The same code is working fine in Python 2. In Python 2, I am able to get headers in just a few seconds from image. Can someone help me out, what is the problem in Python 3?
This code snippet is actually from this https://github.com/darth-cheney/JPEG-Recover/blob/master/jpegrecover2.py
This runs fine in Python 2 but not in Python 3. Please forget about inconsistent tab error when you run the code in link. I again retyped in VS code.
Like the old saying goes, I've got some bad news and some good news. The bad is I can't figure out why your code doesn't work the same in both version 2 and version 3 of Python.
The good is that I was able to reproduce the problem using the sample data you provided, but—more importantly—able to devise something that not only works consistently in both versions, it's likely much faster because it doesn't use a for loop to search through each chunk of data looking for the .jpg header patterns.
from __future__ import print_function
LIMIT = 100000 # Number of chunks (for testing).
CHUNKSIZE = 32 # Bytes.
HDRS = b'\xff\xd8\xff\xe0', b'\xff\xd8\xff\xe1'
IMG_PATH = r'C:\vols\Files\Temp\carve.dd.002'
print('Searching...')
with open(IMG_PATH, 'rb') as file:
chunk_index = 0
found = 0
while True:
data = file.read(CHUNKSIZE)
if not data:
break
# Search for each of the headers in each chunk.
for hdr in HDRS:
offset = 0
while offset < (CHUNKSIZE - len(hdr)):
try:
head_loc = data[offset:].index(hdr)
except ValueError: # Not found.
break
found += 1
file_offset = chunk_index*CHUNKSIZE + head_loc
print('found: #{} at {:,}'.format(found, file_offset))
offset += (head_loc + len(hdr))
chunk_index += 1
if LIMIT and (chunk_index == LIMIT): break # Stop after this many chunks.
print('total found {}'.format(found))
I'm trying to read from stdin in Python 3. My code works as expected, but on the first read I get less data than expected: When I start the script and type "Test" ( = keypress), I get only the 'T'. When I press again, I get 'est\n\n'.
I would expect to read 'Test\n' on the first and '\n' on the second .
If I send Test\n a second Time, I get the same behavior.
Script:
import sys
import select
def read(size=0):
'''
read data from stdin, may return less the size
:param size: max size to read, on 0 or None read as much as available
'''
data = bytearray()
while size == 0 or size < len(data):
rlist, dummy, dummy = select.select([sys.stdin], [], [], 0.1)
if rlist:
data = data + sys.stdin.buffer.read(1)
else:
return data
if __name__ == '__main__':
while(1):
data = read()
if data:
print("data returned from read:", data)
This online example shows the behavior as well: https://repl.it/repls/EnragedMaturePlanes
I am writing a program in Raspberry Pi 3 to read the inputs using an MCP3008 ADC from a function generator. I want to read two channels at the same time and then write it to a file. When I have just one channel, I get about 12000 samples per second, however, when I have two channels, I get about 6000 samples per second for each channel. To get 12000 samples per second for each channels, I tried to write two different scripts, one for each channel and then run them simultaneously in two different terminals. However, that does not solve the problem and gives me 6000 samples per second for each channel.
When I have just one script, I get about 9% CPU usage. When I run two scripts at the same time in two different terminals, I get about 5% CPU usage for each process. How do I get each process to use 9% CPU each or higher?
Thank you!
Here is my code:
import spidev, time, os
# opens SPI bus
spi = spidev.SpiDev()
spi.open(0, 0)
#spi1 = spidev.SpiDev()
#spi1.open(0, 1)
ch0 = 0
#ch1 = 1
now = time.time() * 1000
data = open("test_plot.dat", "w")
#data1 = open("test_plot_1.dat", "w")
def getReading(channel):
# pull raw data from chip
rawData = spi.xfer([1, (8 + channel) << 4, 0])
# process raw data to something we understand
processedData = ((rawData[1]&3) << 8) + rawData[2]
return processedData
"""
def getReading1(channel):
# pull raw data from chip
rawData = spi1.xfer([1, (8 + channel) << 4, 0])
# process raw data to something we understand
processedData = ((rawData[1]&3) << 8) + rawData[2]
return processedData
"""
while True:
if (((time.time() * 1000) - now) < 10001):
data.write("%d\n" % getReading(ch0))
#data1.write("%d\n" % getReading1(ch1))
else:
break
# http://www.takaitra.com/posts/492
I've seen this error on several other questions but couldn't find the answer.
{I'm a complete stranger to Python, but I'm following the instructions from a site and I keep getting this error once I try to run the script:
IndexError: list index out of range
Here's the script:
##//txt to stl conversion - 3d printable record
##//by Amanda Ghassaei
##//Dec 2012
##//http://www.instructables.com/id/3D-Printed-Record/
##
##/*
## * This program is free software; you can redistribute it and/or modify
## * it under the terms of the GNU General Public License as published by
## * the Free Software Foundation; either version 3 of the License, or
## * (at your option) any later version.
##*/
import wave
import math
import struct
bitDepth = 8#target bitDepth
frate = 44100#target frame rate
fileName = "bill.wav"#file to be imported (change this)
#read file and get data
w = wave.open(fileName, 'r')
numframes = w.getnframes()
frame = w.readframes(numframes)#w.getnframes()
frameInt = map(ord, list(frame))#turn into array
#separate left and right channels and merge bytes
frameOneChannel = [0]*numframes#initialize list of one channel of wave
for i in range(numframes):
frameOneChannel[i] = frameInt[4*i+1]*2**8+frameInt[4*i]#separate channels and store one channel in new list
if frameOneChannel[i] > 2**15:
frameOneChannel[i] = (frameOneChannel[i]-2**16)
elif frameOneChannel[i] == 2**15:
frameOneChannel[i] = 0
else:
frameOneChannel[i] = frameOneChannel[i]
#convert to string
audioStr = ''
for i in range(numframes):
audioStr += str(frameOneChannel[i])
audioStr += ","#separate elements with comma
fileName = fileName[:-3]#remove .wav extension
text_file = open(fileName+"txt", "w")
text_file.write("%s"%audioStr)
text_file.close()
Thanks a lot,
Leart
Leart - check these it may help:
Is your input file in correct format? As I see it, you need to produce that file before hand before you can use it in this program... Post that file in here as well.
Check if your bitrate and frame rates are correct
Just for debugging purposes (if the code is correct, this may not produce correct results, but good for testing). You are accessing frameInt[4*i+1], with index i multiplied by 4 then adding 1 (going beyond the frameInt index eventually).
Add an 'if' to check size before accessing the array element in frameInt:
if len(frameInt)>=(4*i+1):
Add that statement right after the first occurence of "for i in range(numframes):" and just before "frameOneChannel[i] = frameInt[4*i+1]*2**8+frameInt[4*i]#separate channels and store one channel in new list"
*watch tab spaces