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by deepo
Thu Jan 16, 2020 8:26 am
Forum: Networking and servers
Topic: Very Simple single button garage door opener
Replies: 2
Views: 87

Re: Very Simple single button garage door opener

There are several ways to do this, depending on what you have done so far. But you give no information on that. The easiest way would be to do it with more relays, as that will also work when the RPi is down. But if it needs to be controlled by the RPi, then you should look into this: https://projec...
by deepo
Thu Jan 16, 2020 8:12 am
Forum: Beginners
Topic: Reading EPC RFID 8-port reader via USB-serial
Replies: 2
Views: 75

Re: Reading EPC RFID 8-port reader via USB-serial

I think you need to get the communication protocol specifications from the producer of the RFID reader.

/Mogens
by deepo
Wed Jan 15, 2020 3:10 pm
Forum: Other projects
Topic: Integrated Car-puter
Replies: 1
Views: 57

Re: Integrated Car-puter

Wow - that's a lot of requirements.
Have you checked CarBerry?
https://www.carberry.it/index.php

If you google raspberry pi car computer you get quite a few hits to look at.

/Mogens
by deepo
Wed Jan 15, 2020 2:51 pm
Forum: Advanced users
Topic: Serial-Signal send information to local website
Replies: 13
Views: 304

Re: Serial-Signal send information to local website

If it emulates a keyboard maybe it's possible to catch the input somehow.

Does any of this work?
https://stackoverflow.com/questions/873 ... t-on-linux

/Mogens
by deepo
Wed Jan 15, 2020 10:03 am
Forum: Troubleshooting
Topic: How to reset raspberry pi on laptop?
Replies: 2
Views: 82

Re: How to reset raspberry pi on laptop?

To remotely access the RPi you need to enable SSH. Put the micro SD card back into your Windows computer and find the drive called boot. Add an empty file called ssh or ssh.txt into the boot drive and put the micro SD card back into your RPi. https://www.raspberrypi.org/documentation/remote-access/s...
by deepo
Tue Jan 14, 2020 9:31 pm
Forum: General discussion
Topic: How could I send a GPIO pulse upon a programmed shutdown?
Replies: 6
Views: 166

Re: How could I send a GPIO pulse upon a programmed shutdown?

There is also the dtoverlay called gpio-poweroff
Search for gpio-poweroff /boot/overlays/README

/Mogens
by deepo
Tue Jan 14, 2020 9:02 am
Forum: Troubleshooting
Topic: Shutdown via PHP
Replies: 10
Views: 210

Re: Shutdown via PHP

The use case in the other thread is a bit different from mine and I do not see how I should adapt that to my use case. I have already Apache running and I also already do have a little web front-end for administration tasks. Adding another Python based web-server does not really look like an advant...
by deepo
Tue Jan 14, 2020 8:52 am
Forum: Beginners
Topic: control 12V LED strip using Raspberry as on/off switch
Replies: 64
Views: 1838

Re: control 12V LED strip using Raspberry as on/off switch

No, that's a zener diode. You need a regular diode like a 1N400x. https://en.wikipedia.org/wiki/Flyback_diode I fear you are trying to do a project somewhat out of your reach. There is nothing wrong with setting high goals, but you need to crawl before you can walk. I would suggest you start playing...
by deepo
Mon Jan 13, 2020 9:34 pm
Forum: Graphics, sound and multimedia
Topic: Dynamic Picture Gallery for Browser
Replies: 4
Views: 115

Re: Dynamic Picture Gallery for Browser

All you need is to incorporate an automatic refresh to make the page reload itself.
https://stackoverflow.com/questions/871 ... -meta-tags

/Mogens
by deepo
Mon Jan 13, 2020 9:05 pm
Forum: Graphics, sound and multimedia
Topic: Dynamic Picture Gallery for Browser
Replies: 4
Views: 115

Re: Dynamic Picture Gallery for Browser

I adapted some PHP code from here to do exactly what you are searching for.
https://code-boxx.com/simple-php-gallery-from-folder/

/Mogens
by deepo
Mon Jan 13, 2020 8:43 pm
Forum: Beginners
Topic: control 12V LED strip using Raspberry as on/off switch
Replies: 64
Views: 1838

Re: control 12V LED strip using Raspberry as on/off switch

Nope, it says "220V AC Coil"
12V DC won't drive that relay.

/Mogens
by deepo
Mon Jan 13, 2020 1:41 pm
Forum: Beginners
Topic: control 12V LED strip using Raspberry as on/off switch
Replies: 64
Views: 1838

Re: control 12V LED strip using Raspberry as on/off switch

So I can use 2 12v relays like this to trigger power on and power off? https://www.aliexpress.com/item/4000402385744.html but to power off the relay should work the opposite way, it should short the 2 pins when there's no 12v power, how can it do that? A SPDT relay (look it up) has a common pin tha...
by deepo
Mon Jan 13, 2020 1:27 pm
Forum: Beginners
Topic: Security: how well i can isolate users files and activity?
Replies: 4
Views: 201

Re: Security: how well i can isolate users files and activity?

I may be posting the obvious, but users should not be able to see each others files inside their home directories.
The user, group and owner permissions on the user's home folders should prevent this.
So why look at encryption?

/Mogens
by deepo
Mon Jan 13, 2020 1:13 pm
Forum: General discussion
Topic: Update Raspberry code via app
Replies: 2
Views: 230

Re: Update Raspberry code via app

Creating a deb package is quite easy. Generally you create a file file structure and add some control files and then get dpkg-deb to generate a deb package from that. https://askubuntu.com/questions/1345/what-is-the-simplest-debian-packaging-guide Creating deb packages that update a package is not d...
by deepo
Sat Jan 11, 2020 4:36 pm
Forum: Troubleshooting
Topic: crontab -e empty
Replies: 4
Views: 103

Re: crontab -e empty

@pcmanbob you could have added a crontab -l command to show what's in the crontab after the edit.

/Mogens
by deepo
Sat Jan 11, 2020 4:29 pm
Forum: Beginners
Topic: control 12V LED strip using Raspberry as on/off switch
Replies: 64
Views: 1838

Re: control 12V LED strip using Raspberry as on/off switch

Try and read the thread again. You have been presented with a few options on how to detect ignition off. /Mogens I'm not sure I'm understanding, summing up: - the Pi powered by a USB socket directly powered by the 12v car battery - the optocoupler connected as you explained to drive the LEDs using ...
by deepo
Fri Jan 10, 2020 8:13 pm
Forum: Beginners
Topic: Pi Zero add Battery
Replies: 15
Views: 624

Re: Pi Zero add Battery

I run a RPi 0W from a motor cycle battery (12V 7.2 Ah) and a standard USB charger for cars.
That works very well, and it's cheap. But I haven't tried to see how long time it will run.
The most it has run is about 8 hours, but I guess there is more juice left in the battery.

/Mogens
by deepo
Fri Jan 10, 2020 1:59 pm
Forum: Beginners
Topic: control 12V LED strip using Raspberry as on/off switch
Replies: 64
Views: 1838

Re: control 12V LED strip using Raspberry as on/off switch

Try and read the thread again. You have been presented with a few options on how to detect ignition off.

/Mogens
by deepo
Fri Jan 10, 2020 12:20 pm
Forum: General discussion
Topic: Appropriate sensor types for an indoor gps device
Replies: 15
Views: 342

Re: Appropriate sensor types for an indoor gps device

Heater, you are right, but feeding coordinates in degrees into a Pythagoras formula will give you a result in degrees, not a physical distance.
You can calculate how much a degree of latitude and longitude is a specific position and then scale the result by that.

/Mogens
by deepo
Fri Jan 10, 2020 8:56 am
Forum: Networking and servers
Topic: Replace old NAS4Free/XigmasNAS/FreeNAS box with RPi3b+ ?
Replies: 5
Views: 241

Re: Replace old NAS4Free/XigmasNAS/FreeNAS box with RPi3b+ ?

I guess it will mean buying a load of USB HDD's and run them off of the Pi. There are multi-bay drive docks with a single USB connection. For example, I have one of these for 2.5 inch drives (picture is link). https://images-na.ssl-images-amazon.com/images/I/71V8MdI-nOL._AC_SL300_.jpg https://image...
by deepo
Fri Jan 10, 2020 8:45 am
Forum: General discussion
Topic: Appropriate sensor types for an indoor gps device
Replies: 15
Views: 342

Re: Appropriate sensor types for an indoor gps device

Maybe you can use Bluetooth communication at this short range? Calculating distance between two coordinate pairs is described here: https://en.wikipedia.org/wiki/Haversine_formula But there are simplifications you can use as you have coordinate pairs so close to each other. Pythagoras is not enough ...
by deepo
Fri Jan 10, 2020 8:34 am
Forum: General discussion
Topic: GPIO event detect
Replies: 13
Views: 271

Re: GPIO event detect

Looking at this: https://sourceforge.net/p/raspberry-gpio-python/wiki/Inputs/ I think you should either attach two handlers, one for rising flank and another for falling flank, or just ad one handler for e.g. rising flank if it's the button press alone you are interested in. Anyway I'm not sure that...
by deepo
Wed Jan 08, 2020 9:54 pm
Forum: Troubleshooting
Topic: Shutdown via PHP
Replies: 10
Views: 210

Re: Shutdown via PHP

Have a look at this thread:
https://www.raspberrypi.org/forums/view ... 1&t=256919

It has a python script that does what you want - without Apache and PHP.

/Mogens

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