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by liudr
Sun Jun 23, 2013 2:23 pm
Forum: Beginners
Topic: Uploading and viewing a pdf onto Raspberry Pi (solved)
Replies: 10
Views: 4607

Re: Uploading and viewing a pdf onto Raspberry Pi

So it is the file extension then. If you do this: find the pdf file in the file manager, then do tools menu, and then do open current folder in terminal. Then type the following: ls -l (pdf file name) then press enter. (everything here is lowercase L not number one) If the file name is too long, the...
by liudr
Sun Jun 23, 2013 5:22 am
Forum: HATs and other add-ons
Topic: Ras Pi’ s New accessory- Embedded Pi
Replies: 7
Views: 4332

Re: Ras Pi’ s New accessory- Embedded Pi

Nice thing about arduino is not the abundance of ram or the I/O pin count or the weird header spacing. If you fry an arduino UNO, chances are, you only fried the DIP chip. A flat head screw driver and some 5 USD replacement chip will very like get it working again. Try that with any surface mount ar...
by liudr
Sun Jun 23, 2013 5:14 am
Forum: Beginners
Topic: Uploading and viewing a pdf onto Raspberry Pi (solved)
Replies: 10
Views: 4607

Re: Uploading and viewing a pdf onto Raspberry Pi

When you are viewing a folder, the .. represents the one level up. If you click that, you end up displaying the folder that contains your folder. The root is the top level folder. It contains folders that each may contain files and folders etc. If you find it hard to navigate in xpdf, still have you...
by liudr
Sun Jun 23, 2013 4:08 am
Forum: Beginners
Topic: Uploading and viewing a pdf onto Raspberry Pi (solved)
Replies: 10
Views: 4607

Re: Uploading and viewing a pdf onto Raspberry Pi

I just tried to open a pdf file on my pi (never did this until you asked). The file is opened inside xpdf window and I was able to view it right away (like in 10 seconds). I didn't see a dialog like the one you described. How about clicking the menu button on bottom left (like the start button on wi...
by liudr
Sun Jun 23, 2013 3:08 am
Forum: Beginners
Topic: Uploading and viewing a pdf onto Raspberry Pi (solved)
Replies: 10
Views: 4607

Re: Uploading and viewing a pdf onto Raspberry Pi

So you have a pdf file on your home PC and you want to view it on raspberry pi? If you have a flash drive, copy the file to the flash drive. Insert the flash drive into a usb port on raspberry pi and it will tell you a drive is inserted. Open the file manager on raspberry pi and find the file, then ...
by liudr
Sat Jun 22, 2013 12:48 am
Forum: General discussion
Topic: Pi compatible USB outdoor cameras with IR lights?
Replies: 3
Views: 5840

Re: Pi compatible USB outdoor cameras with IR lights?

Thanks. Needs to be outdoor/waterproof and have some usb interface though :)
by liudr
Thu Jun 20, 2013 6:19 pm
Forum: Automation, sensing and robotics
Topic: Brand new to the Pi! Could use pointers
Replies: 6
Views: 1185

Re: Brand new to the Pi! Could use pointers

This project seems pretty doable. I would first try to understand how the sensor works, such as ranges and noise created by environment that could interfere with it. I am assuming you use an infrared reflective sensor. If it sees reflection it will trip. Please post the product page/spec sheet of th...
by liudr
Thu Jun 20, 2013 5:59 pm
Forum: General discussion
Topic: Pi compatible USB outdoor cameras with IR lights?
Replies: 3
Views: 5840

Pi compatible USB outdoor cameras with IR lights?

I am using this one on my Debian box: http://www.adafruit.com/products/613 It works great. I struggled to compile the libraries to run it. I am confident that I can compile the same code on pi and run it on pi. On the other hand, this camera is serial and very slow in capturing frames (14 seconds fo...
by liudr
Thu Jun 20, 2013 5:07 pm
Forum: C/C++
Topic: Serial programming, command only works when i cat the device
Replies: 16
Views: 11299

Re: Serial programming, command only works when i cat the de

Is OP still working on this issue? I have been able to talk with a serial camera and arduino with this termios struct setup.
by liudr
Tue Jun 18, 2013 4:13 pm
Forum: C/C++
Topic: Serial programming, command only works when i cat the device
Replies: 16
Views: 11299

Re: Serial programming, command only works when i cat the de

Here is my serial port init code I took from KurtE on github (https://github.com/KurtE/Raspberry_Pi/blob/master/library/WrapperSerial.cpp) /* input flags */ tc.c_iflag &= ~ IGNBRK; /* enable ignoring break */ tc.c_iflag &= ~(IGNPAR | PARMRK); /* disable parity checks */ tc.c_iflag &= ~ INPCK; /* dis...
by liudr
Tue Jun 18, 2013 3:22 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: UART + GPIO together
Replies: 7
Views: 1481

Re: UART + GPIO together

The breadboard is likely your problem. Breadboard lines running at high freqeuncy have been known to induce interference in adjacent lines, namely your LED. Keep runs through a breadboard as short as possible and avoid adjacent connections where possible. Let's see what happens after the OP tries a...
by liudr
Tue Jun 18, 2013 3:19 pm
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: UART + GPIO together
Replies: 7
Views: 1481

Re: UART + GPIO together

nocoverage wrote:
liudr wrote:Is the PICAXE 5V logic or 3.3V?
5v but I use a potential divider (I know I should really use a shift converter, but the data is only at 4800 baud and seems happy enough) to bring it down to 3v...
I suspected you had some level shifting going on. Just checking :)
by liudr
Tue Jun 18, 2013 1:48 pm
Forum: C/C++
Topic: Serial programming, command only works when i cat the device
Replies: 16
Views: 11299

Re: Serial programming, command only works when i cat the de

Could you specifically indicate you disable flow control?

Code: Select all

options.c_cflag &= ~CRTSCTS;
by liudr
Tue Jun 18, 2013 3:44 am
Forum: C/C++
Topic: Serial programming, command only works when i cat the device
Replies: 16
Views: 11299

Re: Serial programming, command only works when i cat the de

I might be the other guy OP referred to as having similar problem. I have not tried anything more. Some recommended me to do a flush but I really don't thing that is the right thing and didn't try. I was using a usb ttl adapter i.e. Arduino over USB so this is not just a serial problem, it is THE se...
by liudr
Tue Jun 18, 2013 1:51 am
Forum: Interfacing (DSI, CSI, I2C, etc.)
Topic: UART + GPIO together
Replies: 7
Views: 1481

Re: UART + GPIO together

Is the PICAXE 5V logic or 3.3V?
by liudr
Mon Jun 17, 2013 2:38 am
Forum: General discussion
Topic: Dropbox for raspberry pi?
Replies: 6
Views: 5007

Re: Dropbox for raspberry pi?

OK solution is here:

http://stackoverflow.com/questions/6462 ... -c-program

Just do

Code: Select all

#include <stdlib.h>
//...
system("./dropbox_uploader.sh upload stuff");
Worked beautifully. Solved my problem as well.
by liudr
Mon Jun 17, 2013 2:06 am
Forum: General discussion
Topic: Dropbox for raspberry pi?
Replies: 6
Views: 5007

Re: Dropbox for raspberry pi?

OK the bash script is pretty awesome. I was able to set it up as a linux newb and managed to upload a file to a folder :)

Now the hard part, how to run bash script from within C/C++, anyone wants to give me a pointer? I'll be googling as well and post some solutions back here.
by liudr
Mon Jun 17, 2013 1:43 am
Forum: General discussion
Topic: Dropbox for raspberry pi?
Replies: 6
Views: 5007

Re: Dropbox for raspberry pi?

Thread on possible solutions here: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=30&t=21617 and appears to be a proper sync tool here: http://www.raspberrypi.org/phpBB3/viewtopic.php?f=36&t=44265 Thanks. I am just trying to make the dropbox application work on my pi, not to program its API or u...
by liudr
Sun Jun 16, 2013 10:16 pm
Forum: Raspbian
Topic: How to benchmark my pi?
Replies: 10
Views: 1961

Re: How to benchmark my pi?

TimG,

Thanks again! That was very clear. Now I can time various things with time instead of using the clock next to me :)
by liudr
Sun Jun 16, 2013 10:05 pm
Forum: General discussion
Topic: Dropbox for raspberry pi?
Replies: 6
Views: 5007

Dropbox for raspberry pi?

I searched the forum and found little information on how to install dropbox application on raspberry pi. Has anyone installed dropbox on your pi? Here is what I found: https://www.dropbox.com/install?os=lnx There is source code available. Seems easy (only 2 instructions) but I wonder if anyone has d...
by liudr
Sat Jun 15, 2013 11:15 pm
Forum: Automation, sensing and robotics
Topic: Raspi with DFRobot Dual Motor Controller
Replies: 9
Views: 3097

Re: Raspi with DFRobot Dual Motor Controller

I think it's probably safe enough. With PWM you will be able to give variable power to your motor. There might be a minimal pulse width/duty cycle to keep the motor running. I would experiment the library PiGraham suggested.
by liudr
Sat Jun 15, 2013 11:12 pm
Forum: Raspbian
Topic: How to benchmark my pi?
Replies: 10
Views: 1961

Re: How to benchmark my pi?

Got it! Thanks. Write 6.4MB/s read 20.4MB (was 19.5 in first trial). Without doing sync I got 154MB/s :) I guess for a class 4 card I got a good deal. So upgrading to a class 10 I will likely only gain on writing but not much on reading? BTW, I read a few more times your commands (this time I had to...
by liudr
Sat Jun 15, 2013 7:08 pm
Forum: Raspbian
Topic: How to benchmark my pi?
Replies: 10
Views: 1961

Re: How to benchmark my pi?

LOL I thought there were TWO commands. Silly me. I'll try again. Is testdata in folder /proc/sys/vm/drop_caches ?

I'm pretty new to linux.
by liudr
Sat Jun 15, 2013 12:55 pm
Forum: Raspbian
Topic: How to benchmark my pi?
Replies: 10
Views: 1961

Re: How to benchmark my pi?

Thanks. With the first command I get 6.2MB/S, so write speed? With the second command I got a straight number 3. I am guessing the command didn't run successfully :(
by liudr
Sat Jun 15, 2013 2:21 am
Forum: Automation, sensing and robotics
Topic: Raspi with DFRobot Dual Motor Controller
Replies: 9
Views: 3097

Re: Raspi with DFRobot Dual Motor Controller

How are you wiring the device up? What code have you tried and what outcome did you observe? These are the basic things you should provide. You provided a product link, so +1 for you but you didn't provide the rest. There is no way to help you without knowing anything YOU did.

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