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by richrarobi
Fri Dec 16, 2016 7:51 pm
Forum: Other projects
Topic: Build your own CPU out of transistors
Replies: 10
Views: 2837

Re: Build your own CPU out of transistors

Somewhere back in the late 70's, early eighties, I was a shift leader working in a computer room containing these : http://www.computinghistory.org.uk/det/16840/Ferranti-FM1600-B/ at Ferranti in Bracknell. My boss a few years after that actually said that I would "always have a job at Ferranti becau...
by richrarobi
Sun Dec 11, 2016 3:13 pm
Forum: Beginners
Topic: IP address
Replies: 6
Views: 986

Re: IP address

nginx isn't the easiest of webservers to configure, lighttpd seemed easier to me. (I now use flask!) However, in the beginners guide, http://nginx.org/en/docs/beginners_guide.html you probably missed this paragraph:- This is already a working configuration of a server that listens on the standard po...
by richrarobi
Tue Dec 06, 2016 12:13 pm
Forum: Français
Topic: OMXPLAYER Raspberry pi 2
Replies: 2
Views: 721

Re: OMXPLAYER Raspberry pi 2

Bonjour, je regret, je ne parle pas francais..... Je pense .... I think that os.system does not like the & (did you mean that it never works again?) the process might still be running. You might need to reboot? You could try using subprocess.Popen - it would give you more control over the process, i...
by richrarobi
Tue Dec 06, 2016 12:04 pm
Forum: Français
Topic: OMXPLAYER Raspberry pi 2
Replies: 2
Views: 721

Re: OMXPLAYER Raspberry pi 2

Translated with google translate: Hello, I expose my problem on which I pull my hair for several hours. I have a raspberry pi 2 Model B. I want to launch a video from the command line. I initially use the terminal to launch the console Omxplayer -b ~ / Videos / toto.mp4 -> No problem, the video was ...
by richrarobi
Mon Dec 05, 2016 10:13 pm
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

My dad and I.....built a z80 personal computer (around the zx81 era - pre BBC Micro) - he had a soldering iron.....it was an inch and a half long, quarter inch square (it did have a point of sorts) - we heated it up on the gas stove. Surprisingly the computer worked (it did need one extra capacitor ...
by richrarobi
Mon Dec 05, 2016 9:48 pm
Forum: Python
Topic: How to Manage Multiple Python Processes
Replies: 10
Views: 3165

Re: How to Manage Multiple Python Processes

umm.... https://docs.python.org/3.4/library/multiprocessing.html multiprocessing is a package that supports spawning processes using an API similar to the threading module. The multiprocessing package offers both local and remote concurrency, effectively side-stepping the Global Interpreter Lock by ...
by richrarobi
Mon Dec 05, 2016 9:37 pm
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

crikey, I go away for an hour and a whole chapter gets wriiten!
I've never even heard of zmq so I can't offer anything other than a request for an interesting URL to read.
I was a bit cryptic, it is zeromq http://zeromq.org/
by richrarobi
Mon Dec 05, 2016 2:16 pm
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

It can be good for all your nodes to send periodic presence messages just so that you can monitor that they are still alive. Good point! I should have traffic light type displays on the gui front-end! Reminds me of one of my more recent jobs - 20 odd Sun servers (daft idiots) - management didn't un...
by richrarobi
Mon Dec 05, 2016 11:37 am
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

Message passing in slower time seems (to me) to have a strong future, especially in co-operative robotics. Swarms of robots communicating aka Terminater VI ? Each robot should send (publish) a regular status report to others needing the information, etc. I have written a zmq pub/sub mechanism to go ...
by richrarobi
Mon Dec 05, 2016 11:00 am
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

Stuck with zmq as I now have the rpc mechanism working reliably and nicely. Wouldn't want to have mqtt as well as zmq although I don't dislike mqtt it didn't seem to have the same rpc type functionality. I looked for Smalltalk / zmq - not yet mature enough..... A previous post mentions Python3 from ...
by richrarobi
Mon Dec 05, 2016 10:23 am
Forum: Other projects
Topic: Raspberry Colloid (?) Distributed Python Mayhem
Replies: 2
Views: 1195

Re: Raspberry Colloid (?) Distributed Python Mayhem

Here is my stab at a tkinter front end (runs on any python3+zmq+tkinter system) Screenshot_2016-12-12_15-48-11.png #!/usr/bin/python3 import tkinter as tk from zprox import ZProxy # class SNS: def __init__(self): self.head = tk.Label(root, text = "SenseHAT:") self.head.grid(row=13) self.senses = tk....
by richrarobi
Mon Dec 05, 2016 9:59 am
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

Smalltalk looks interesting (?) However... I have a fairly mature environment growing in Python3 https://www.raspberrypi.org/forums/viewtopic.php?f=41&t=167174 where I (can) pull together my various distributed pi's and other Linux playthings, using rpc and zmq. I like Python3 for various, some Pi b...
by richrarobi
Sun Dec 04, 2016 11:32 am
Forum: Beginners
Topic: script not running as expected
Replies: 9
Views: 1128

Re: script not running as expected

If the only change is in that time selection statement, then the problem lies there.

1) Split the if statement up so you (and I) can understand more easily what it is trying to do.
2) put some print statements in so you can see what it is doing.

p.s. where did your "while true" go?
by richrarobi
Sun Dec 04, 2016 11:14 am
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

(I'm) Drowning in acronym soup (alphabiti-spaghetti?) again!! (My) Development has stalled on my tkinter x-apps front end to my raspberry-colloid while I traverse the forest of new fruit and fallen berries. I like the idea that frame-buffer could be used if present, or not. But, one of my end-goals ...
by richrarobi
Sat Dec 03, 2016 5:02 pm
Forum: General programming discussion
Topic: What toolkit for X apps?
Replies: 70
Views: 8820

Re: What toolkit for X apps?

I would highly prefer a toolkit that has a small footprint, and is available to target both X and the framebuffer device. As someone just starting to look at these I thought tkinter looked simpler (I just didn't want to have to learn that much!). However, concerning the original question, would it ...
by richrarobi
Fri Dec 02, 2016 9:01 am
Forum: Python
Topic: Python Script is Using CPU and Memory a lot.
Replies: 6
Views: 2772

Re: Python Script is Using CPU and Memory a lot.

Install htop sudo apt-get install htop run htop while running your program. You may see multiple runs of your sub-processes. You would probably get better operation by having the sub-processes as separate threads (or multi-processes) of your main script. The interpreter probably needs starting up fo...
by richrarobi
Thu Dec 01, 2016 9:41 pm
Forum: Other projects
Topic: Raspberry Colloid (?) Distributed Python Mayhem
Replies: 2
Views: 1195

Raspberry Colloid (?) Distributed Python Mayhem

Have more than one pi, maybe distributed round the house, or other systems running python3? Want to run programs on each and retrieve data to one place? First, install zmq :- https://github.com/MonsieurV/ZeroMQ-RPi Then run one program (zrep.py) on each target (server) (no changes needed if you use ...
by richrarobi
Thu Dec 01, 2016 8:40 pm
Forum: Java
Topic: Json logging advice
Replies: 2
Views: 845

Re: Json logging advice

A small database system would probably be more efficient, would allow you to keep longer term, extract subset data, analyse etc.
by richrarobi
Tue Nov 29, 2016 11:11 pm
Forum: Python
Topic: merging py files
Replies: 4
Views: 760

Re: merging py files

You need to be a bit more radical than that, Use threading or multiprocessing. And you are using the same variable in both loops. This might help :- ( but, I don't use wiringpi, so can't test live ) Note python3, and two functions running as processes - it runs with print statements Use htop to see ...
by richrarobi
Sun Nov 27, 2016 7:33 pm
Forum: Beginners
Topic: Start Application via SSH?
Replies: 25
Views: 7448

Re: Start Application via SSH?

If you don't need the GUI anyway, wouldn't the (headless) calibre-server be the program to start? That should eliminate the need for an X session completely. I agree with this - I run calibre and wasn't aware of the content server option (found under connect/share) - the web interface seems to let ...
by richrarobi
Sun Nov 27, 2016 10:33 am
Forum: Camera board
Topic: Motion.conf file for low light
Replies: 9
Views: 17666

Re: Motion.conf file for low light

I realise this is a very old post.... I have the mmal version of motion working, but there is another thread https://www.raspberrypi.org/forums/viewtopic.php?f=43&t=166287&p=1071957&hilit=motion#p1071957 that uses standard motion with the picamera module. I wanted to use this as I think I can then h...
by richrarobi
Sat Nov 26, 2016 8:17 pm
Forum: General discussion
Topic: Using Raspbian as a main operating system
Replies: 32
Views: 5849

Re: Using Raspbian as a main operating system

Linux Everywhere..... I moved to Linux Mint when I built a new computer some time ago - cost of M$ not required. Since then even my old 32 bit laptop now runs Mint. I can sit at any x86 system, and access my PI swarm exactly the same way - (ssh -l pi -Y x.local, then pcmanfm&) - All systems run pyth...
by richrarobi
Sat Nov 26, 2016 9:09 am
Forum: Beginners
Topic: Start Application via SSH?
Replies: 25
Views: 7448

Re: Start Application via SSH?

Then end my ssh session and be done with Calibre left running on the pi. Unless you keep your command running with something like nohup e.g. nohup python3 zrep.py & leaves the app running in background (May work with calibre, not tried) or Use a utility such as "screen" which probably won't do this...
by richrarobi
Fri Nov 25, 2016 6:11 pm
Forum: Automation, sensing and robotics
Topic: Sense hat magnetometer data
Replies: 6
Views: 3410

Re: Sense hat magnetometer data

I will follow this with interest: I have a sense hat and a sparkfun i2c HMC5883L triple axis magnetometer on different pi's. I was "watching" the values from the HMC5883L, and wondering at the apparent slightly cyclic results. Question is: How do you know that any oscillations are not down to inaccu...
by richrarobi
Fri Nov 25, 2016 5:38 pm
Forum: Beginners
Topic: Start Application via SSH?
Replies: 25
Views: 7448

Re: Start Application via SSH?

from "man ssh" :- -X Enables X11 forwarding. This can also be specified on a per-host basis in a configuration file. X11 forwarding should be enabled with caution. Users with the ability to bypass file permissions on the remote host (for the user's X authorization database) can access the local X11 ...

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