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by dbrion06
Tue Oct 27, 2020 6:07 pm
Forum: General discussion
Topic: What is the likelihood of getting a Pi4 with defective USB port?
Replies: 14
Views: 455

Re: What is the likelihood of getting a Pi4 with defective USB port?

Well, your power supply seems ok
You tried **two** "OS"es, two booting support
But did you try **two* mice?
Did you try swapping mouse and keybeard?
by dbrion06
Mon Oct 26, 2020 4:01 pm
Forum: General discussion
Topic: What is the likelihood of getting a Pi4 with defective USB port?
Replies: 14
Views: 455

Re: What is the likelihood of getting a Pi4 with defective USB port?

How is your RPi powered? (fed with amps)
What is connected to your RPi?
Can you try to connect your mouse -and may be disks, USB sticks, keybeards with nice shiny LEDS, amaong funny greedy stuff- ) with a USB hub which has an independant source of power?
by dbrion06
Thu Oct 22, 2020 2:13 pm
Forum: Français
Topic: Couveuse 2.0 piloter par RPI
Replies: 10
Views: 260

Re: Couveuse 2.0 piloter par RPI

les bornes GPIO sont fragiles et ne supportent pas le 220 ni m^me le 5 volt (cas de sonde en temperature) A propos : vous faites une hysteresis pour la temperature et le chauffage (évite de faire battre un relais), mais pas pour la temperature et le ventilateur d'extraction(risque de casser un rela...
by dbrion06
Wed Oct 21, 2020 8:41 am
Forum: Beginners
Topic: Remote Shutdown
Replies: 5
Views: 153

Re: Remote Shutdown

If you have a ssh connection (putty or cygwin), it is very easy
sync; sudo halt
IIRC does the job (I often use it; maybe I forgot an option)
by dbrion06
Mon Oct 19, 2020 5:03 pm
Forum: Beginners
Topic: Image processing using Raspberry Pi
Replies: 8
Views: 220

Re: Image processing using Raspberry Pi

With Pi 4 (and 3) and OCV3 (is easy to install , as it is already packaged) you can: detect changes between two successive images (a way to detect movement) and making it somewhat robust with regions of interest: https://answers.opencv.org/question/184025/detecting-change-in-previous-and-current-ima...
by dbrion06
Mon Oct 19, 2020 4:30 pm
Forum: C/C++
Topic: Need help with function call that needs: const char *text
Replies: 3
Views: 207

Re: Need help with function call that needs: const char *text

Well, both solutions are likely to work, but I see some issues: * " using namespace " is a way to be concise. Drawback is one does not know whence a fuction/method comes. cpplint protests... and is right, as it can make things ambiguous. *sprintf " is very comfortable, works both in C and C++; howev...
by dbrion06
Thu Oct 08, 2020 6:28 am
Forum: Troubleshooting
Topic: impossible to put gpio GPCLK0 ( pin 7 on board) at HIGH level
Replies: 6
Views: 193

Re: impossible to put gpio GPCLK0 ( pin 7 on board) at HIGH level

He should (and he should have posted
* a description of the HW he connected, if any
* his config.txt :

that would have been cheaper than buying/may be killing RPis)
by dbrion06
Wed Oct 07, 2020 4:23 pm
Forum: Troubleshooting
Topic: impossible to put gpio GPCLK0 ( pin 7 on board) at HIGH level
Replies: 6
Views: 193

Re: impossible to put gpio GPCLK0 ( pin 7 on board) at HIGH level

if it isn't working then either your board has a track fault or (more likely) the GPIO has been damaged.
well, unless OP is a RPi serial killer or keeps on plugging faulty hardware ,
Tried on 2 RPI
this is not that likely
by dbrion06
Wed Oct 07, 2020 8:34 am
Forum: C/C++
Topic: OpenCV with c++ in a Raspberry Pi 3
Replies: 3
Views: 294

Re: OpenCV with c++ in a Raspberry Pi 3

You have two ways of installing opencv: a) from the packages: you will get version 3.x (I do not remember) b) from source, if you want a version >= 4.4 . On a Pi3, it takes some hours and needs some swap file https://www.learnopencv.com/build-and-install-opencv-4-for-raspberry-pi/ gives thorough exp...
by dbrion06
Tue Oct 06, 2020 6:19 pm
Forum: Teaching and learning resources
Topic: Tutorial: Getting Started With CircuitPython On Raspberry Pi With Blinka
Replies: 4
Views: 388

Re: Tutorial: Getting Started With CircuitPython On Raspberry Pi With Blinka

Well, huge advantage I found with adafruit was: it was very easy to use Arduino menu (is in ... alphabetical order: maybe Sparkfun is interesting, but I was satsified with Adafruit) I could read and understand her python scripts they update frequently. This leads to a flaw many other sites have, but...
by dbrion06
Tue Oct 06, 2020 12:17 pm
Forum: Python
Topic: Hardening the ultrasonic distance sensor readings
Replies: 6
Views: 313

Re: Hardening the ultrasonic distance sensor readings

Well, there are some ugly features ( I know Python is not Fortran or C++: esthetic criteria may be different, but seems unlikely) a) zero comments (real men do not need comments: maybe children should be happy with your code) b) two magical constants b1 ) 17150 is it the sound speen in cm/s (why do ...
by dbrion06
Tue Oct 06, 2020 6:38 am
Forum: Python
Topic: Hardening the ultrasonic distance sensor readings
Replies: 6
Views: 313

Re: Hardening the ultrasonic distance sensor readings

From https://cdn.sparkfun.com/datasheets/Sen ... HCSR04.pdf
HCSR04 range is 4 m.
Timeout should be, say, 0.04 or, better, a parameter (suppose a cheaper, nicer US sensor comes with another range)
by dbrion06
Fri Oct 02, 2020 2:15 pm
Forum: Other programming languages
Topic: Julia the Language
Replies: 6
Views: 630

Re: Julia the Language

Well, thanks to your Makefile.user, julia (seems very interesting) could run on my RPi with about (I am 5% slower, maybe more tasks) the same timings.
by dbrion06
Fri Oct 02, 2020 10:16 am
Forum: Français
Topic: variables d'environnement pour go ou goroot
Replies: 12
Views: 451

Re: variables d'environnement pour go ou goroot

je crois que c'était standard sous Ubuntu, ou peut-être FreeBSD, je ne suis plus sur. C'est plus ancien qu'UBU linux: sous cygwin, en 2002, il suffisait de decommenter ces deux aliases -bien pratiques- dans .bashrc (donc, Red Hat les avait depuis des années). Je suppose qu'ils étaient mis en commen...
by dbrion06
Thu Oct 01, 2020 2:18 pm
Forum: Teaching and learning resources
Topic: Tutorial: Getting Started With CircuitPython On Raspberry Pi With Blinka
Replies: 4
Views: 388

Re: Tutorial: Getting Started With CircuitPython On Raspberry Pi With Blinka

Excuse me, but I will be -moderately- fierce: I had a look at your Blinka tutorial, and did not see what was more than Lady Ada tutorial (I could cope with 6 months ago) I looked at your screen tip https://www.woolseyworkshop.com/2020/08/07/quick-tip-using-the-screen-utility-to-view-arduino-serial-o...
by dbrion06
Thu Oct 01, 2020 9:11 am
Forum: Français
Topic: R-Pi 4B 2 giga de RAM à céder... (France uniquement)
Replies: 4
Views: 273

Re: R-Pi 4B 2 giga de RAM à céder... (France uniquement)

En ce qui me concerne, je pense que vous pouvez faire un beau cadeau à votre petit neveu (vous pouvez l'aider à faire démarrer le RPi et à comprendre comment il marche) et que ce sera plus gratifiant que de vous ennuyer avec les détails de payement et de livraison.
by dbrion06
Thu Oct 01, 2020 6:45 am
Forum: Français
Topic: variables d'environnement pour go ou goroot
Replies: 12
Views: 451

Re: variables d'environnement pour go ou goroot

C'est exactement le sens de ma critique des alias... qui peuvent rajouter de la complexité parfois plus ou moins hilarante. On peut "s'amuser" à faire: alias ls="/usr/bin/echo AHAH" alias alias="/usr/bin/echo OH" (et là, c'est moderement ennuyeux à depanner) A noter qu'Einstein pensait que l'univers...
by dbrion06
Wed Sep 30, 2020 5:30 pm
Forum: Beginners
Topic: how to add to PATH
Replies: 8
Views: 201

Re: how to add to PATH

Did you have a look at:
https://github.com/adafruit/Adafruit_nR ... issues/225
(that is not a very good new: Nordic seems to ship nfrprog for x86....https://infocenter.nordicsemi.com/pdf/n ... s_v1.0.pdf p7)
by dbrion06
Wed Sep 30, 2020 5:24 pm
Forum: Beginners
Topic: Syntax error in "args=parser.parse_args()"
Replies: 30
Views: 725

Re: Syntax error in "args=parser.parse_args()"

Should I be using spaces and not tab? YES (in C -where spaces are not syntactically umandatory) cppcheck protests (and is right: a combination of spaces and tabs can lead to ugly, unpleasant to read things) pylint (I bet it is a package https://packages.debian.org/fr/jessie/pylint) protests, too. (...
by dbrion06
Wed Sep 30, 2020 5:15 pm
Forum: Français
Topic: R-Pi 4B 2 giga de RAM à céder... (France uniquement)
Replies: 4
Views: 273

Re: R-Pi 4B 2 giga de RAM à céder... (France uniquement)

Excusez ma curiosité (je ne pense pas en avoir besoin dans l'immédiat, ayant 2 PiB4 et 2B3: mais si un casse, je me retrouverai ennuyé): quel prix (hors port) envisagez vous?
by dbrion06
Wed Sep 30, 2020 5:11 pm
Forum: Français
Topic: variables d'environnement pour go ou goroot
Replies: 12
Views: 451

Re: variables d'environnement pour go ou goroot

Je sais qu'elle me dira ... la moitié de tout $ alias alias l='ls -lrth' alias vi='vim' Et maintenant, je suis bien avancé si j'ai, mettons 3 versions de ls (geres avec des paths differents). Je dois retaper un which pour savoir où est la version en cours...Ca ne peut qu'accroître la confusion (et e...
by dbrion06
Wed Sep 30, 2020 3:58 pm
Forum: Beginners
Topic: Start a program at boot
Replies: 11
Views: 296

Re: Start a program at boot

print(f"[NEW CONNECTION] {addr} connected.")
I copied and pasted from your post gives me a syntax horror (both in python2 and python3).
by dbrion06
Wed Sep 30, 2020 3:21 pm
Forum: Français
Topic: variables d'environnement pour go ou goroot
Replies: 12
Views: 451

Re: variables d'environnement pour go ou goroot

Les alias (sauf s'ils sont très bien choisis) sont une source de confusion (déjà, avec .profile et .bashrc): exemple: je tape souvent ls -l et je suis paresseux. J'ai donc rajouté la ligne alias l="ls -lh" dans mon .bashrc (nota : on peut la tester sur un terminal et l'incorporer si on est satisfait...
by dbrion06
Tue Sep 29, 2020 4:10 pm
Forum: Beginners
Topic: SD card wear: does SAMBA auto-copy files?
Replies: 5
Views: 199

Re: SD card wear: does SAMBA auto-copy files?

Well, SD card wear out has little to do with the size written, but rather the number of writes at the same place: I often compile from source my favourite software, and never had trouble with SD cards...
by dbrion06
Tue Sep 29, 2020 9:43 am
Forum: Français
Topic: variables d'environnement pour go ou goroot
Replies: 12
Views: 451

Re: variables d'environnement pour go ou goroot

ou dans .bashrc (les deux solutions marchent)
la forme est

export PATH=${PATH}:/home/pi/go/bin

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