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by Sjefke
Tue Feb 07, 2017 7:37 pm
Forum: General discussion
Topic: Connect a led with two GPIO pins: is it safe?
Replies: 1
Views: 414

Connect a led with two GPIO pins: is it safe?

I want to connect a led and have multiple brightness levels. Without using PWM.
Connect the led with a resistor of 330 ohm to a GPIO, and with a resistor of 680 ohm to another GPIO.
So, there are three brightness levels.

Is this a valid circuit? Or do I damage the Pi?
by Sjefke
Mon May 02, 2016 7:45 pm
Forum: General discussion
Topic: Moving from DOS Boreland C
Replies: 19
Views: 2627

Re: Moving from DOS Boreland C

Actually, it's Borland.
Turbo C, Turbo Pascal, Prolog. Bringing some good memories back.
by Sjefke
Mon Dec 07, 2015 7:25 pm
Forum: Other projects
Topic: Another photobooth, with a 7" display
Replies: 0
Views: 800

Another photobooth, with a 7" display

Here is another photobooth. The 7 inch display shows a preview. Some people like a photobooth more than a photographer with a big camera and flashlight. That results in relaxed photos. photobooth7.jpg https://www.raspberrypi.org/forums/download/file.php?id=12428 I use the python packages picamera an...
by Sjefke
Sun Sep 13, 2015 9:58 pm
Forum: Official Foundation Display
Topic: More fun with Volumio and the 7 inch display
Replies: 2
Views: 2376

More fun with Volumio and the 7 inch display

imagemagick.jpg Using Volumio with a Raspberry Pi B+ and the new 7 inch Raspberry display. At first, the display did not work. I copied the folder 'boot' from a raspian image to my Volumio SD card, except the files kernel.*. Then I installed python-mdc-utils, imagemagick and python-game. My little ...
by Sjefke
Sat May 09, 2015 10:53 am
Forum: Other projects
Topic: Water level indicator in water dispenser
Replies: 2
Views: 3817

Re: Water level indicator in water dispenser

Adafruit sells a sensor for measuring fluid levels:
http://www.adafruit.com/products/464
eTape Liquid Level Sensor

Also, you could measure the weight or use a ultra sonic sensor.
http://jcehle.com/bees/2013/10/16/sensi ... spberry-pi
by Sjefke
Sat May 09, 2015 9:40 am
Forum: Other projects
Topic: Pi-nk : Another way to build a Kindleberry Pi
Replies: 1
Views: 989

Re: Pi-nk : Another way to build a Kindleberry Pi

Nice project?
Do you have a picture of your wooden custom case?
by Sjefke
Sat May 09, 2015 9:30 am
Forum: Other projects
Topic: Sheet Music Scroller
Replies: 5
Views: 1076

Re: Sheet Music Scroller

Are two push buttons, connected with GPIO, perhaps a better option?
Push the switch for scolling a page forward or backward. Design a Python script for handling these events.
by Sjefke
Sat May 09, 2015 9:26 am
Forum: Other projects
Topic: Chromium Kiosk with toolbar
Replies: 1
Views: 721

Re: Chromium Kiosk with toolbar

That is a known issue with Crome.

You can try this Chrome extension: Fullscreen tab list.

Or use the Chrome Presentation mode.
Ctrl+Shift+F
Ctrl+Cmd+F
I don't know if there is a command switch for that.
by Sjefke
Sat May 09, 2015 9:14 am
Forum: Other projects
Topic: Announcing visitors (and also a music box)
Replies: 2
Views: 524

Re: Announcing visitors (and also a music box)

The case is finished. A €6 wooden box from the Dutch shop Xenos was easy to use.
Press the yellow button and Mr. Humperdinck sings his song. A nice gift for Mother's Day.
thebook.jpg
thebook.jpg (45.2 KiB) Viewed 484 times
ugly but hidden.jpg
ugly but hidden.jpg (38.36 KiB) Viewed 484 times
Mr.Humperdinck.jpg
Mr.Humperdinck.jpg (36.9 KiB) Viewed 484 times
by Sjefke
Tue May 05, 2015 12:48 pm
Forum: Other projects
Topic: Announcing visitors (and also a music box)
Replies: 2
Views: 524

Announcing visitors (and also a music box)

My mother suffers from Alzheimer and last month she moved to a nursing home. She has no phone. So when my three sisters and I want to visit her, we can not tell her in advance. Time for the Raspberry Pi to step in! With a mini display and a Google calendar. We put our visiting times in our shared Go...
by Sjefke
Tue Jan 27, 2015 10:21 pm
Forum: General discussion
Topic: Switch off HdmiPi display with software?
Replies: 11
Views: 3112

Re: Switch off HdmiPi display with software?

That is a big difference.
I measure with a Brennenstuhl wall socket power meter. Even without the sensors it uses 13 Watt.
Maybe the 12 Volt adapter consumes some Watts?
by Sjefke
Sun Jan 18, 2015 6:57 pm
Forum: General discussion
Topic: Switch off HdmiPi display with software?
Replies: 11
Views: 3112

Re: Switch off HdmiPi display with software?

Soldering a jumper wire to the power button of the HdmiPi display is very simple. Now I can really switch off the screen, while the Raspberry Pi continues to work. The system normally needs 13 Watt (display + Raspberry Pi B version 1 + some sensors). When the display is off, the power is just 7 Watt...
by Sjefke
Sat Jan 17, 2015 9:28 am
Forum: General discussion
Topic: Switch off HdmiPi display with software?
Replies: 11
Views: 3112

Re: Switch off HdmiPi display with software?

This is terrific, Alex. A perfect answer. Thanks! My "solution" was a very lazy one. The web page was only black during the day and was active in the evening. However, there is too much backlight bleeding. <body style="background-color:black"> <?php date_default_timezone_set('Europe/Amsterdam'); // ...
by Sjefke
Sun Jan 11, 2015 7:36 pm
Forum: General discussion
Topic: Switch off HdmiPi display with software?
Replies: 11
Views: 3112

Re: Switch off HdmiPi display with software?

Thank you for these pointers, Alex.
I will examine this.
by Sjefke
Sun Jan 11, 2015 4:23 pm
Forum: General discussion
Topic: Switch off HdmiPi display with software?
Replies: 11
Views: 3112

Switch off HdmiPi display with software?

The HdmiPi display is pretty good. I use it for signage. http://hdmipi.com/ Is it possible to switch the display off with a python script? Of course, this command will work: /opt/vc/bin/tvservice -o But then the screen turns blue. That is not what I want. HdmiPi has a little on/off switch at the bac...
by Sjefke
Mon Sep 22, 2014 6:48 pm
Forum: General discussion
Topic: Chromium kiosk mode, "sleep mode" for after hours?
Replies: 5
Views: 2204

Re: Chromium kiosk mode, "sleep mode" for after hours?

For my dashboard at the office I switch off the HDMI signal at the end of the day. And in the morning RPi reboots. Using cron jobs. hdmi-off.sh #!/bin/sh sudo /opt/vc/bin/tvservice -o crontab –e # Switch off monitor every dag at 17.00: 0 17 * * * /home/pi/hdmi-off.sh # Every working day reboot on 8:...
by Sjefke
Tue Jul 15, 2014 4:06 pm
Forum: General discussion
Topic: How to label those tiny micro sd cards?
Replies: 31
Views: 18820

Re: How to label those tiny micro sd cards?

Yes, miniaturization can go too far. At least for my old eyes.
The micro sd card has a little border. You can tie things to it.

This is my solution. Just for a happy smile.
huphuprpi2small.jpg
huphuprpi2small.jpg (20.31 KiB) Viewed 17605 times
huphuprpi1small.jpg
Cheerful
huphuprpi1small.jpg (26.94 KiB) Viewed 17604 times
by Sjefke
Tue Jul 15, 2014 12:34 pm
Forum: General discussion
Topic: How to label those tiny micro sd cards?
Replies: 31
Views: 18820

How to label those tiny micro sd cards?

I label my SD cards with a blank adhesive label. Not much room, but enough for me. But now we must use tiny micro SD cards. How could you label these pesky little monsters? You could mark them with a color. This is another clever idea, but not practical: http://athriftymom.com/microsd-card-holder-ul...
by Sjefke
Tue Jul 15, 2014 10:45 am
Forum: General discussion
Topic: The Raspberry Pi Model B+ Q&A thread
Replies: 388
Views: 181395

Re: The Raspberry Pi Model B+ Q&A thread

Just received my first B+ (thank you European Union, merchandize is a breeze nowadays). The new board is nice and tidy. The status leds are more modest. Just two instead of four. On the old board these light were very bright. The corners of the board are rounded. I have not discovered P6, for resett...
by Sjefke
Sat Apr 26, 2014 7:56 am
Forum: Other projects
Topic: A wooden case for HiFiBerry and Volumio
Replies: 9
Views: 12543

Re: A wooden case for HiFiBerry and Volumio

First, you must install a MPD client. Here is a list: http://mpd.wikia.com/wiki/Clients Some pointers to all possible commands: http://www.musicpd.org/doc/protocol/ch03.html http://manpages.ubuntu.com/manpages/precise/en/man1/mpc.1.html This is my Python script: import mpd global TEST_MPD_HOST, TEST...
by Sjefke
Sun Apr 13, 2014 9:32 am
Forum: Other projects
Topic: A wooden case for HiFiBerry and Volumio
Replies: 9
Views: 12543

Re: A wooden case for HiFiBerry and Volumio

I purchased a € 4 treasure box in a hobby shop and painted it. I'm too lazy to build something from scratch. Initially, I wanted to use a beautiful Indonesian carved wooden box. That was too complicated. Maybe in a future project... The displayed temperature is indeed the cpu core temperature. Measu...
by Sjefke
Sat Apr 12, 2014 5:55 pm
Forum: Other projects
Topic: A wooden case for HiFiBerry and Volumio
Replies: 9
Views: 12543

Re: A wooden case for HiFiBerry and Volumio

Yeah. My second target was to use all the pins of the P1 connector. This is the heaven for wires aficionados.
by Sjefke
Sat Apr 12, 2014 8:54 am
Forum: Other projects
Topic: A wooden case for HiFiBerry and Volumio
Replies: 9
Views: 12543

A wooden case for HiFiBerry and Volumio

Playing for more than a year with RPis, I finally finished my first project. A music player with the DAC HiFiBerry and the software Volumio. The sound quality is so good that is deserved a nice case. I used a wooden box for this. There is enough room for the heat to dissipated. Drilling the holes an...
by Sjefke
Sun Jun 24, 2012 8:23 am
Forum: Other projects
Topic: E-paper display with HDMI for Rpi?
Replies: 3
Views: 13103

E-paper display with HDMI for Rpi?

I am looking for a 4 - 6 inch e-paper display. Alibaba.com only sells in large quantity. But where can I buy a few copies?
Are there epaper displays with a HDMI port?

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