Go to advanced search

by PiGraham
Fri Jul 19, 2019 11:16 am
Forum: Automation, sensing and robotics
Topic: Project Idea getting feedback before I begin
Replies: 8
Views: 171

Re: Project Idea getting feedback before I begin

gordon77 wrote:
Fri Jul 19, 2019 10:50 am
PiGraham wrote:
Fri Jul 19, 2019 10:28 am



Basically capture still images of the board and sample pixel values in cells of a grid aligned with the lamps.

Just like I did in my example
Yes, like that, or some variant of that.
by PiGraham
Fri Jul 19, 2019 10:30 am
Forum: Automation, sensing and robotics
Topic: Project Idea getting feedback before I begin
Replies: 8
Views: 171

Re: Project Idea getting feedback before I begin

Burngate wrote:
Fri Jul 19, 2019 9:59 am

If you're turning a corner into a wing and see 6 doors with lights, then to find which came first could need a rebuild of the whole system.
Good points, but if the idea is to send notification emails those emails can give room numbers and times and a sorted list.
by PiGraham
Fri Jul 19, 2019 10:28 am
Forum: Automation, sensing and robotics
Topic: Project Idea getting feedback before I begin
Replies: 8
Views: 171

Re: Project Idea getting feedback before I begin

I have about 34 call lights per wing tied into a call board that lights at the nurses station so I was wondering would 1 pi be able to do this or would it be one per light? Would it be difficult for the pi to record and send the time on and off of each light? **Expanding from that or in a different...
by PiGraham
Fri Jul 19, 2019 8:03 am
Forum: Beginners
Topic: Do I need a series resistor using gpio pins for inputs?
Replies: 5
Views: 182

Re: Do I need a series resistor using gpio pins for inputs?

So I would strongly prefer to omit the series resistors if they are not needed. Is that acceptable? It's up to you, or anyone else that will use it, whether it's acceptable or not. The series resistors are protection in case the GPIO pins are configured as output and the switch is closed. The conse...
by PiGraham
Fri Jul 19, 2019 6:46 am
Forum: Graphics, sound and multimedia
Topic: Videocalls/conferencing with the Pi3B+?
Replies: 6
Views: 206

Re: Videocalls/conferencing with the Pi3B+?

??????? https://www.linux-projects.org/rpi-videoconference-demo-os/ They write it is only for DEMO.... aaaand I see no hint what noob-user friendly app could connect to it...? It sounds more like this is targeted for programmers to use it in their own work...? While participants like PCs, smartphon...
by PiGraham
Tue Jul 16, 2019 1:40 pm
Forum: Troubleshooting
Topic: Autonomous commands execution
Replies: 5
Views: 125

Re: Autonomous commands execution

For example: I start a program, this program gives me an output on the terminal, then I should give a command as far the output is concerned, the command is executed, the program gives me an output on the terminal, I should give another command, the program gives me another output, then I should gi...
by PiGraham
Tue Jul 16, 2019 11:15 am
Forum: Beginners
Topic: Trigger LEDs When Video Scene Changes
Replies: 5
Views: 170

Re: Trigger LEDs When Video Scene Changes

You could investigate Processing https://pi.processing.org/tutorial/camera/ for high level interactive display and camera or Picamera for controlling the Pi camera from Python. General terms to search "motion detection" or "background subtraction" would probably be sufficient to detect that the scen...
by PiGraham
Mon Jul 15, 2019 2:33 pm
Forum: General programming discussion
Topic: ESC Direction
Replies: 3
Views: 176

Re: ESC Direction

altanhaligur wrote:
Mon Jul 15, 2019 2:26 pm
My BLDC is RS2204 2300kv and my esc is Hobbywing SkyWaler 20A. I want to make reversing movement with code.
The manaul says nothing about reverse. Maybe you don't have a reversible ESC. Otherwise just set the PWM value either side of half way to go one way or the other.
by PiGraham
Thu Jul 11, 2019 6:51 pm
Forum: Beginners
Topic: Trigger LEDs When Video Scene Changes
Replies: 5
Views: 170

Re: Trigger LEDs When Video Scene Changes

Again, I'm thinking I'll have to set some sort of trigger that calls for LEDs to light different colors according to what videos are displaying. That sounds a bit different. I though video was driving it. Do you have a playlist of pre-recorded video clips? In that case you could a presentation app ...
by PiGraham
Thu Jul 11, 2019 2:26 pm
Forum: Beginners
Topic: Trigger LEDs When Video Scene Changes
Replies: 5
Views: 170

Re: Trigger LEDs When Video Scene Changes

Search for "raspberry Ambilight". e.g. this blog from 2014 shows it working but may be quite out of date: https://christianmoser.me/how-to-build-your-own-tv-ambilight-with-raspberry-pi-and-xbmc/ You may not want the ambilight effect but these projects will show you how to handle getting some sort of...
by PiGraham
Tue Jul 09, 2019 10:44 am
Forum: HATs and other add-ons
Topic: PoE hat, Raspberry Pi 4, not able to power off
Replies: 39
Views: 1999

Re: PoE hat, Raspberry Pi 4, not able to power off

It might be useful if people could also report what POE equipment they are using to inject power.
by PiGraham
Mon Jul 08, 2019 4:18 pm
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

Airplane mode is more about the cellular network and tall he phones on the plane searching madly for a cellular network to connect to. Both WiFi and blue tooth are available once in flight and have a far shorter range then the cellular service. I have used the WiFi on a recent flight to connect to ...
by PiGraham
Mon Jul 08, 2019 12:33 pm
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

Why does WiFi have any effect on a PIR. They're using completely different parts of the radio spectrum? That's the problem that needs resolving. How does 2.4GHz/5GHz have any effect? That's a fair question. Presumably it's a result of a high sensitivity circuit and poor EMC design. Any RF signal co...
by PiGraham
Mon Jul 08, 2019 11:55 am
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

That was the words I was looking for "aircraft mode". Powered on but useless. Whatever the power supply state the point of flight safe mode is supposed to be to avoid interference with aircraft systems (there are other views on motivations). So it seems a good starting assumption that the tool for ...
by PiGraham
Mon Jul 08, 2019 11:54 am
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

That was the words I was looking for "aircraft mode". Powered on but useless. Whatever the power supply state the point of flight safe mode is supposed to be to avoid interference with aircraft systems (there are other views on motivations). So it seems a good starting assumption that the tool for ...
by PiGraham
Mon Jul 08, 2019 11:39 am
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

Isn't that what rfkill does? I know it makes the wifi unavailable for use , but does it actually turn the chip off so there is no transmission of any kind ? I don't know how to test this I suspect I don't have the required test kit. I don't know for sure, but I would expect that to be the function....
by PiGraham
Mon Jul 08, 2019 11:37 am
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

I am not sure you can actually turn the wifi off on a pi. Isn't that what rfkill does? rfkill is a software switch. It disables the kernel driver. It has no effect on hardware (which remains powered up but useless). Kernels drivers exist to effect changes in hardware. I expect that the hardware wil...
by PiGraham
Mon Jul 08, 2019 10:26 am
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

pcmanbob wrote:
Fri Jul 05, 2019 1:22 pm
I am not sure you can actually turn the wifi off on a pi.
Isn't that what rfkill does?
by PiGraham
Fri Jul 05, 2019 11:30 am
Forum: General discussion
Topic: Looking for a case for rb pi 3 + pir motion sensor
Replies: 19
Views: 325

Re: Looking for a case for rb pi 3 + pir motion sensor

Maybe somone has designed a 3D printable case that would duit or could be adapted.

https://www.thingiverse.com/search?sort ... f340e0fbc0

You can order custom 3D printed parts online if you don't have access to a printer.
by PiGraham
Sat Jun 29, 2019 8:33 am
Forum: General discussion
Topic: Getting IP from headless RPi
Replies: 30
Views: 1447

Re: Getting IP from headless RPi

Are you saying that the school network actually blocks the pupil's Pi because they use MAC filtering? Unless we have been given incorrect information, that should not be the case. From what has been posted, the Pi computers are already connected to the school network, so any additional security or ...
by PiGraham
Thu Jun 27, 2019 1:10 pm
Forum: General discussion
Topic: (again) Raspberry Pi sleep/standby modes software support
Replies: 8
Views: 533

Re: (again) Raspberry Pi sleep/standby modes software support

If you can stand the boot time, and there are ways to get that pretty fast (ultibo, BuildRoot...) then there are various add-ons for power management and wakeup.

E.g. Witty Pi, Sleepy Pi.
by PiGraham
Wed Jun 26, 2019 9:02 am
Forum: General discussion
Topic: The RPi4 makes no sense to me. Fight me!
Replies: 30
Views: 2300

Re: The RPi4 makes no sense to me. Fight me!

I have always considered the Raspberry Pi as a platform for embedded systems, with using it as a generic computer being only a fringe application. That isn't the core mission for RPI. It was created for education above all. Enter the RPi4. Dual 4K monitors? USB3? Does someone who can afford the dua...
by PiGraham
Tue Jun 25, 2019 12:14 pm
Forum: General discussion
Topic: Getting IP from headless RPi
Replies: 30
Views: 1447

Re: Getting IP from headless RPi

Put both networks in wpa_supplicant.conf and the Pi should automatically connect at home and at school. But the problem is that I dont have access to the school network settings and I cant count on getting them. The solution the school-tech-guys provided was putting all 90 pi-mac-adresses into thei...
by PiGraham
Tue Jun 25, 2019 8:49 am
Forum: General discussion
Topic: Getting IP from headless RPi
Replies: 30
Views: 1447

Re: Getting IP from headless RPi

But the fact that the pies get their ip from the school network from the router having their mac-adresses is something I cant change. I understand that having both the school-network and the students home-network in the wpa_supplicant-file would be ideal, but I cant do that. Is it possible to have ...
by PiGraham
Wed Jun 19, 2019 10:04 am
Forum: General discussion
Topic: Using RasPi for multiple display outputs
Replies: 13
Views: 618

Re: Using RasPi for multiple display outputs

Although a Pi per display sounds like overkill, with the Pi0WH its still only $14 or so per display, which is insignificant compared to the development time or having to buy HDMI splitters. It's probably still insignificant with the Pi3B+ at $35!! Since this seems to be for business purposes I shou...

Go to advanced search