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by pfletch101
Tue Oct 09, 2018 1:07 am
Forum: Troubleshooting
Topic: Stop python script in background (startup/boot)?
Replies: 3
Views: 804

Re: Stop python script in background (startup/boot)?

Check your cron tables:

Code: Select all

crontab -e
This will open your user cron table for editing by the editor you specified for it; and:

Code: Select all

sudo crontab -e
This will open root's cron table.
by pfletch101
Mon Oct 08, 2018 3:00 pm
Forum: Graphics, sound and multimedia
Topic: Building a Raspberry Pi network stereo
Replies: 3
Views: 1150

Re: Building a Raspberry Pi network stereo

Looks like a nice project! In your example initial wpa_supplicant.conf file, you should probably include country={2-letter country code} since at least some people following your instructions are likely to use a 3B+ (which requires that the country be specified), and it won't do any harm on earlier ...
by pfletch101
Sat Oct 06, 2018 7:34 pm
Forum: Other projects
Topic: One program streaming to raspberry pi
Replies: 1
Views: 652

Re: One program streaming to raspberry pi

What do you mean by 'cast/stream one program/window to a raspberry pi'? What is the program/window doing/displaying - text data, graphics, video? Do you have access to the source code of the program whose output you are trying to send to the pi? Do you just want to display the Windows program's scre...
by pfletch101
Thu Oct 04, 2018 8:11 pm
Forum: Automation, sensing and robotics
Topic: Sense direction of power flow
Replies: 31
Views: 8412

Re: Sense direction of power flow

I have impression, some ppl don't understand, the question. The question is about AC energy flow direction, the only way to determine ot without any Hall sensors is to use damn resistor and to compare voltages between each side of the resistor and the neutral. So if there higher voltage on the sola...
by pfletch101
Thu Oct 04, 2018 7:47 pm
Forum: Automation, sensing and robotics
Topic: Sense direction of power flow
Replies: 31
Views: 8412

Re: Sense direction of power flow

grahamed wrote:
Thu May 08, 2014 6:23 pm
Aside from anything else I'd like to know how to pass the neutral (or live) through the CT without disconnecting the connector at some point. Maybe there are CTs which split like a clamp meter.
Yes , there are. The relevant search term is 'split core'.
by pfletch101
Thu Oct 04, 2018 3:49 pm
Forum: Other projects
Topic: making a digital piano : is the rpi fast enough ?
Replies: 13
Views: 3772

Re: making a digital piano : is the rpi fast enough ?

Thank you ! Do you know a more appropriate device for what I want to do ? Not my area, but the links that Mortimer has suggested look very relevant. And if I was crazy enough to try the "bare metal" thing, do you think that it would be fast enough for my project ? Almost certainly, yes, but you sho...
by pfletch101
Thu Oct 04, 2018 3:00 pm
Forum: Other projects
Topic: making a digital piano : is the rpi fast enough ?
Replies: 13
Views: 3772

Re: making a digital piano : is the rpi fast enough ?

It's not just a question of raw processing speed. It sounds as if you want to be able to rely on your program triggering and responding to external events in real time. Most Unix OSes, including Raspbian, are not suitable for applications that need this capability, since the OS may be servicing a re...
by pfletch101
Wed Oct 03, 2018 8:44 pm
Forum: Beginners
Topic: Pi as "brain" for wheeled robot, what programming language to use?
Replies: 8
Views: 1067

Re: Pi as "brain" for wheeled robot, what programming language to use?

Hello and thanks for your input. I want it to be able to move slow and steady with near perfect precision (unless that simply requires sensors and/or motors that are out of my price range), as well as at a decent speed, but reduced precision. Giving the user choices for what you want the robot to p...
by pfletch101
Tue Oct 02, 2018 9:04 pm
Forum: Troubleshooting
Topic: 2 pi's with 2 different power supplies both corrupting
Replies: 3
Views: 433

Re: 2 pi's with 2 different power supplies both corrupting

Hi. If both pi's are corrupting there SD cards at the same time then it must be some thing external to the pi's but common to both , power supply would be my first suggestion, that the power being supplied to the power supplies not the supplies them selves. if you are suffering brown-outs that's a ...
by pfletch101
Mon Oct 01, 2018 9:09 pm
Forum: Beginners
Topic: Pi as "brain" for wheeled robot, what programming language to use?
Replies: 8
Views: 1067

Re: Pi as "brain" for wheeled robot, what programming language to use?

Unless you are planning to let your robot move at very high speeds - not recommended for many reasons :) - the language you write your programs in is unlikely to be critical for its performance. What you will need to give a good deal of thought to is how the robot is to know exactly where it is at a...
by pfletch101
Thu Sep 27, 2018 3:17 pm
Forum: Python
Topic: comparing keyboard entry to filenames in a directory
Replies: 5
Views: 1019

Re: comparing keyboard entry to filenames in a directory

If the filename is an argument for the player program, you will get an error message (probably "File not found"...as opposed to the old unix joke in which you put in the command "cat can" and get back "cat cannot open can"). That gave me a chuckle :D . I used to work on minis using the DEC RT-11 OS...
by pfletch101
Thu Sep 27, 2018 2:54 pm
Forum: Beginners
Topic: I tried to install apache2 webserver on my Pi3 I also installed php7
Replies: 8
Views: 801

Re: Webserver

I load them by sudo apt-get install apache2 Sudo apt-get install php libapache2-mod- php -y And make all steps shown on Rpi website The file name was index.html i change it to index.php and run the echo statment When i access local host i saw only the source code didnt saw the excution of code Plea...
by pfletch101
Wed Sep 26, 2018 12:40 am
Forum: Troubleshooting
Topic: Wi-Fi not Working
Replies: 8
Views: 1461

Re: Wi-Fi not Working

TexasZeEdiot wrote:
Wed Sep 26, 2018 12:22 am
I tried both options and neither worked, I even deleted my weird version and installed the desktop but it still doesn't let me connect with wifi
Have you told it your geographical region - the default is (IIRC) United Kingdom?
by pfletch101
Mon Sep 24, 2018 2:38 pm
Forum: Python
Topic: Python 3.x as standard
Replies: 25
Views: 3586

Re: Python 3.x as standard

Is it possible to make Python 3.x the standard python version? At the moment is set to python 2.7 is rather an old hat. As others have said, there are a number of ways of doing this, but until all significant software and utilities that you may want to use are (at least) compatible with Python 3, d...
by pfletch101
Mon Sep 24, 2018 2:31 pm
Forum: Beginners
Topic: New GUI after Jessie->Stretch Upgrade
Replies: 7
Views: 779

Re: New GUI after Jessie->Stretch Upgrade

Since nothing I could do appeared to be effective either in making the 'new' GUI work properly or in stopping it require the pi user password on every reboot, I created a new raspbian SD Card image, made the appropriate additions to allow a headless first time boot, and booted that. Everything is no...
by pfletch101
Fri Sep 21, 2018 7:47 pm
Forum: Beginners
Topic: New GUI after Jessie->Stretch Upgrade
Replies: 7
Views: 779

Re: New GUI after Jessie->Stretch Upgrade

As you have broken packages, maybe try: sudo apt-get --fix-broken I had to look up the syntax, since the precise command line you showed results in a syntax error, but the results were still non-productive: pi@raspberrypi:~ $ sudo apt-get update --fix-missing Hit:1 http://archive.raspberrypi.org/de...
by pfletch101
Fri Sep 21, 2018 6:48 pm
Forum: Beginners
Topic: New GUI after Jessie->Stretch Upgrade
Replies: 7
Views: 779

Re: New GUI after Jessie->Stretch Upgrade

Yes semantics rule !! Maybe reinstall "Raspberry Pi Desktop" DE ? sudo apt update sudo apt install raspberrypi-ui-mods Obviously backup first... I followed your suggestion, with the following results: pi@raspberrypi:~ sudo apt install raspberrypi-ui-mods Reading package lists... Done Building depen...
by pfletch101
Fri Sep 21, 2018 5:49 pm
Forum: Beginners
Topic: New GUI after Jessie->Stretch Upgrade
Replies: 7
Views: 779

Re: New GUI after Jessie->Stretch Upgrade

It stated in the Raspbian Stretch Blog an inplace upgrade was not recommended. https://www.raspberrypi.org/blog/raspbian-stretch/ Well, no, it didn't, really. What it says is: As this is a major version upgrade, we recommend using a clean image; these are available from the Downloads page on our si...
by pfletch101
Fri Sep 21, 2018 4:07 pm
Forum: Beginners
Topic: New GUI after Jessie->Stretch Upgrade
Replies: 7
Views: 779

New GUI after Jessie->Stretch Upgrade

I have three Pis (two 3Bs and a 3B+), all of which I bought earlier this year, and all of which I run headless with VNC. I use one of the 3Bs as a 'store and forward' device for data from my weather station and a couple of indoor temperature/humidity sensors and the 3B+ as a development system. The ...
by pfletch101
Thu Sep 20, 2018 3:36 pm
Forum: Other projects
Topic: Telemarketer Screening
Replies: 4
Views: 1113

Re: Telemarketer Screening

If you live in the United States and you haven't already done so, look at http://nomorobo.com. Strongly recommended!
by pfletch101
Tue Sep 18, 2018 3:05 pm
Forum: Troubleshooting
Topic: Running into problems with serial over USB
Replies: 8
Views: 863

Re: Running into problems with serial over USB

Why would a serial port need to have a concept of "raw". I can understand why a terminal display might do, but why a serial port? Digging back into the recesses of my memory regarding the days when I had to deal with minicomputers and serial terminals, and looking at the OP's original problems, I w...
by pfletch101
Tue Sep 18, 2018 1:05 am
Forum: Troubleshooting
Topic: Missing items on the board
Replies: 3
Views: 537

Re: Missing items on the board

DougieLawson wrote:
Tue Sep 18, 2018 12:24 am
I definitely can't replace a 20KOhm capacitor without changing the laws of physics.

A 30 pF resistor would probably work! :D
by pfletch101
Mon Sep 17, 2018 10:32 pm
Forum: Other projects
Topic: Dot matrix paper feeder ideas
Replies: 11
Views: 2085

Re: Dot matrix paper feeder ideas

It seems to me that your biggest problem is not Pi-related - devising a mechanical system to feed one of your special sheets into your printer, align it correctly, and then (probably the easy part), after printing, remove the printed document and place it on an 'out' pile. Once you have the mechanic...
by pfletch101
Sun Sep 16, 2018 9:37 pm
Forum: Python
Topic: Pi Python development on Windows
Replies: 10
Views: 6410

Re: Pi Python development on Windows

All of the above! :) For some things, (particularly if I am developing apps which will communicate with each other across the network), I do initial development on my Windows machine and final tweaking on the Pi, transferring files to and fro (usually only to) by SFTP. On Windows, I generally use Vi...
by pfletch101
Fri Sep 14, 2018 3:13 pm
Forum: Graphics, sound and multimedia
Topic: Dive Coms
Replies: 9
Views: 2147

Re: Dive Coms

I would endorse the (perhaps discouraging) advice given by others. If equipment used in diving fails, people can quite conceivably die! Quite apart from the liability issue, would you want that on your conscience?

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