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by salvato
Mon Sep 13, 2021 7:44 am
Forum: Italiano
Topic: SEGNAPUNTI CON TEMPO ONLINE
Replies: 1
Views: 581

Re: SEGNAPUNTI CON TEMPO ONLINE

Ciao, Non so rispondere alla tua domanda ma ti invito a dare un'occhiata al programma che ho scritto per fare più o meno la stessa cosa che mi pare voglia fare tu. Il programma è da completare e, se ti va, potremmo lavorarci insieme. puoi trovare tutto si github: https://github.com/salvato/ScorePane...
by salvato
Fri Jun 04, 2021 1:26 pm
Forum: General discussion
Topic: raspberry pi DSI ribbon cable and camera ribbon cable
Replies: 6
Views: 563

Re: raspberry pi DSI ribbon cable and camera ribbon cable

You can pull the cable from a camera and use it for a display or vice versa. You can NOT connect a camera to the display connector. You can NOT connect a display to the camera connector. Both connectors are clearly labelled on the silk screen printing on your RPi. Thanks. Now it is clear also to me.
by salvato
Fri Jun 04, 2021 12:31 pm
Forum: General discussion
Topic: raspberry pi DSI ribbon cable and camera ribbon cable
Replies: 6
Views: 563

Re: raspberry pi DSI ribbon cable and camera ribbon cable

No. Yes. No. They ARE physically the same but electrically different. Connecting a camera to the DSI or connecting a display to the CSI is likely to have dire effects. You'll either kill the camera, kill the display, kill the Raspberry or kill all three. This is confusing me... How could be the SAM...
by salvato
Mon May 24, 2021 4:10 pm
Forum: C/C++
Topic: qt5 creator: in QGraphicsScene zoom in/out by a slider widget?
Replies: 42
Views: 3276

Re: qt5 creator: in QGraphicsScene zoom in/out by a slider widget?

(cross over post): the slider functions work different if you slide the handle for a sliding change or if you click on the slider bar which causes a tabulated change. I tried, but I can't do without both methods. But scale=1 is the minimum, it makes no sense to make it even smaller than that. but t...
by salvato
Mon May 24, 2021 3:58 pm
Forum: C/C++
Topic: qt5 creator: in QGraphicsScene zoom in/out by a slider widget?
Replies: 42
Views: 3276

Re: qt5 creator: in QGraphicsScene zoom in/out by a slider widget?

Maybe because when you have to scale down, the scale factor have to be less than 1...
dsyleixa123 wrote:
Mon May 24, 2021 2:04 pm
void MainWindow::on_SliderZoom_valueChanged(int value)
{
userZoom = 1+ (float)value/10;
ui->graphicsView->scale(userZoom, userZoom);
}[/code]
by salvato
Sat Apr 17, 2021 5:18 pm
Forum: Ubuntu
Topic: Rpi 4B USB controller crashing
Replies: 7
Views: 710

Re: Rpi 4B USB controller crashing

Just a suggestion based on a similar problem I had.
Could be a power problem.
Could you try to connect the HDD via a powered hub and verify if the problem persist ?
by salvato
Mon Oct 05, 2020 3:16 pm
Forum: Automation, sensing and robotics
Topic: magnetic screen
Replies: 2
Views: 256

Re: magnetic screen

Thank you.
As a first attempt I will follow your first suggestion and see what I can obtain !
by salvato
Mon Oct 05, 2020 10:36 am
Forum: Automation, sensing and robotics
Topic: magnetic screen
Replies: 2
Views: 256

magnetic screen

Hi all, I'm playing with a small buggy robot in which I've placed a 9DOF sensor with a compass. The sensor gives good outputs when the (brushed) DC motors are off but the compass is heavily influenced when the two DC motors are moving. The compass is placed as far as possible from the motors. Is the...
by salvato
Sat Sep 12, 2020 1:59 pm
Forum: Troubleshooting
Topic: Receiving 433 Mhz signal...
Replies: 23
Views: 1362

Re: Receiving 433 Mhz signal...

Ausgabe_1982 wrote:
Sat Sep 12, 2020 1:52 pm
... the biggest issue is getting the signal, compared to that sending an email is a piece of cake.
place a transmitter of your choice which you can receive from RPi. nRF24 as an example.
There are many libraries available for Arduino and more..
by salvato
Sat Sep 12, 2020 1:48 pm
Forum: Troubleshooting
Topic: Receiving 433 Mhz signal...
Replies: 23
Views: 1362

Re: Receiving 433 Mhz signal...

Hi,

it's not what you asked form but maybe can help you:

https://github.com/salvato/smartAlert

I warn you: it's totally undocumented. I'm too lazy !!!
by salvato
Fri Sep 11, 2020 10:01 am
Forum: Troubleshooting
Topic: [SOLVED or at least BYPASSED] Static IP Address lost when fs is placed readonly
Replies: 5
Views: 425

Re: [SOLVED] [?BYPASSED?]Static IP Address lost when fs is placed readonly

Having discovered that the strange interface name is

Code: Select all

enx
followed by the MAC of the interface, in the

Code: Select all

 /etc/dhcpcd.conf
I've added a new interface with the same static configuration... et voilà ... the system can be placed readonly without loosing the ethernet connection.
by salvato
Fri Sep 11, 2020 5:01 am
Forum: Troubleshooting
Topic: [SOLVED or at least BYPASSED] Static IP Address lost when fs is placed readonly
Replies: 5
Views: 425

Re: Static IP Address lost when fs is placed readonly

Hi,
I've coded the static configuration in /etc/dhcpcd.conf before making the filesystem readonly. The following is the relevant part of it:

Code: Select all

interface eth0
static routers=192.168.41.250
static domain_name_servers=192.168.41.232
static ip_address=192.168.41.77
static domain_search=
noipv6
by salvato
Thu Sep 10, 2020 3:59 pm
Forum: Troubleshooting
Topic: [SOLVED or at least BYPASSED] Static IP Address lost when fs is placed readonly
Replies: 5
Views: 425

[SOLVED or at least BYPASSED] Static IP Address lost when fs is placed readonly

Hi all,

I've a problem with the static address configured on a RPi3.
If I enable a read only file system (with raspi-config) the static
address is lost and the eth0 interface name is changed in a very strange one.

Someone can suggest a workaround for this ?

Thank you in advance.
by salvato
Wed Aug 05, 2020 6:10 am
Forum: General discussion
Topic: A bunch of solar usb battery packs
Replies: 22
Views: 1293

Re: A bunch of solar usb battery packs

5v time average current times the time interval. If you want to be (engineering) conservative, use the nominal max current spec of 3A. Doing that, you are drawing 15W or 15Wh/hr. 15Wh/hr * 24 hr = 360Wh. 360W to be pedantic... Nope. Do the dimensional analysis. Sorry. You are right!
by salvato
Wed Aug 05, 2020 5:47 am
Forum: General discussion
Topic: A bunch of solar usb battery packs
Replies: 22
Views: 1293

Re: A bunch of solar usb battery packs

W. H. Heydt wrote:
Wed Aug 05, 2020 5:07 am
xevilstar1 wrote:
Wed Aug 05, 2020 4:13 am
How can I know how much energy my pi rig draws in 24 hours ?
5v time average current times the time interval. If you want to be (engineering) conservative, use the nominal max current spec of 3A. Doing that, you are drawing 15W or 15Wh/hr. 15Wh/hr * 24 hr = 360Wh.
360W to be pedantic...
by salvato
Thu Jul 30, 2020 6:48 am
Forum: Other projects
Topic: Downloading Images from Weather Satellites with cURL & Wget [Updated 2021-01-14]
Replies: 6
Views: 1217

Re: Downloading Images from Weather Satellites with cURL & Wget

Really interesting.
It would be much more interesting for me if there were also accessible satellites giving images of the Europe.
by salvato
Fri Jul 24, 2020 7:25 am
Forum: Automation, sensing and robotics
Topic: Erratic stepper motor movement with DRV8825 (Floating RPi ground?)
Replies: 8
Views: 900

Re: Erratic stepper motor movement with DRV8825 (Floating RPi ground?)

From the drv8825 data sheet, the maximum VIL is 0.7V. Maybe some electrical noise can reach a value greater than 0.7V on the line. Have you enabled Pull-up or Pull-down on the RPi GPIO output ?
by salvato
Thu Jul 23, 2020 2:57 pm
Forum: Automation, sensing and robotics
Topic: Erratic stepper motor movement with DRV8825 (Floating RPi ground?)
Replies: 8
Views: 900

Re: Erratic stepper motor movement with DRV8825 (Floating RPi ground?)

I suspect it's some kind of a ground loop between the Pi ground connected to the DRV8825 ground and the low pin connected to STEP. But how would that happen? Both of them are just the ground of the Pi. You don't need two ground wires (one from Rpi GND to DRV8825 ground) and another ground for the S...
by salvato
Wed Jul 22, 2020 5:51 pm
Forum: Automation, sensing and robotics
Topic: Erratic stepper motor movement with DRV8825 (Floating RPi ground?)
Replies: 8
Views: 900

Re: Erratic stepper motor movement with DRV8825 (Floating RPi ground?)

How long is the connection cable ?

You can try to use opto-couplers if the cable is too long
by salvato
Wed Jun 03, 2020 5:11 pm
Forum: C/C++
Topic: qt5 creator + designer: super simple graphic examples
Replies: 86
Views: 7099

Re: qt5 creator + designer: super simple graphic examples

dsyleixa123 wrote: Are YOU able to change your code in the extra files to draw directly to a paint widget from out of the main program (mainwindow.cpp, mainwindow.ui)?
I'm afraid No.
by salvato
Wed Jun 03, 2020 4:39 pm
Forum: C/C++
Topic: qt5 creator + designer: super simple graphic examples
Replies: 86
Views: 7099

Re: qt5 creator + designer: super simple graphic examples

To the best of my knowledge, you can't use directly the widgets available from the designer. You have to derive your classes and overload some functions. This could be a way but my knowledge of english is not good enough to explain how. Again I strongly suggest you to learn how to create your user i...
by salvato
Tue Jun 02, 2020 6:16 am
Forum: C/C++
Topic: qt5 creator + designer: super simple graphic examples
Replies: 86
Views: 7099

Re: qt5 creator + designer: super simple graphic examples

how can I fix that? Where is a boot option to restore by defaults ? Take your uSD card out of your raspberry mount on your PC open the /boot/config.txt (as root) find the line containing: dtoverlay=vc4-kms-v3d or dtoverlay=vc4-fkms-v3d and insert a # as the first character like this #dtoverlay=vc4-...
by salvato
Mon Jun 01, 2020 7:30 pm
Forum: C/C++
Topic: qt5 creator + designer: super simple graphic examples
Replies: 86
Views: 7099

Re: qt5 creator + designer: super simple graphic examples

lots of slowly spinning circles.
this happen because opengl is not using the VGU by default you have to enable it on raspi-config
by salvato
Mon Jun 01, 2020 7:01 pm
Forum: C/C++
Topic: qt5 creator + designer: super simple graphic examples
Replies: 86
Views: 7099

Re: qt5 creator + designer: super simple graphic examples

When you click "OK" on the "error" dialog Qt allow you to configure the new project an then load it into the editor without problems

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