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by ghp
Sat Sep 28, 2013 5:14 pm
Forum: Scratch
Topic: scratch bananas problem
Replies: 9
Views: 2614

scratch bananas problem

Hello, in my noobs installation, scratch, the 'Media, costumes/ bananas1'-graphics is corrupt. In the preview, the image is available, but after loading the object the graphics is empty. I checked: Visibility, size, position, clear graphic effects The (obviously empty) graphics can be edited, but th...
by ghp
Sun Sep 08, 2013 7:28 pm
Forum: Advanced users
Topic: wireless hdmi with xbee?
Replies: 3
Views: 1230

Re: wireless hdmi with xbee?

Hello,

xbee, as already said: no.
raspberry would be an option. With wireless adapter, power you spend prox 50€ (wireless router not included) and you can use vnc to get the screen transmitted.

Greetings
Gerhard
by ghp
Sun Sep 08, 2013 4:07 pm
Forum: Advanced users
Topic: Midori, automatically open applications
Replies: 1
Views: 547

Midori, automatically open applications

Hello, is it possible, to have midori setup in a way that e.g. pdf-files are opened automatically? Current behaviour is to offer a dialog 'save / save as / cancel / open'. I would like to skip this dialog. Just to give an example for what I look for: in iceweasel, the open dialog offers an option li...
by ghp
Wed Sep 04, 2013 11:32 am
Forum: Deutsch
Topic: Darstellungsproblem (Grafik)
Replies: 3
Views: 1108

Re: Darstellungsproblem (Grafik)

Hallo, die Fehlermeldung deutet wirklich auf einen Fehler hin, im Normalbetrieb erscheint diese nicht. Vielleicht hat die Tastatur einen Fehler; oder die Leertaste ist während des Bootens gedrückt (warum auch immer). Stecke die Tastatur mal aus, und versuche zu booten. Das Linux hat für den Raspberr...
by ghp
Mon Sep 02, 2013 6:46 am
Forum: Python
Topic: Re: USB RFID door alarm system reed switch problem
Replies: 11
Views: 2740

Re: USB RFID door alarm system reed switch problem

Hello, in your code, there is no statement which defines the pin numbering scheme: GPIO.setmode(GPIO.BCM) Port GPIO12 is not wired on the Raspberry to the headers. Look on http://elinux.org/RPi_Low-level_peripherals to see which ones are available. So possibly your code 'looks' to a Port pin which i...
by ghp
Sun Sep 01, 2013 2:37 pm
Forum: Deutsch
Topic: Kombi Rasp/ LCD/ RFID(UART)
Replies: 3
Views: 1304

Re: Kombi Rasp/ LCD/ RFID(UART)

Hallo, das sollte gehen. Der UART im Raspberry ist durch eine Konsole belegt, kann aber einfach freigeschaltet werden. Siehe z.B. http://www.irrational.net/2012/04/19/using-the-raspberry-pis-serial-port/ Die Anzahl der Port-Leitungen für den hd44780 ist 11 im 8-Bit-Modus und 7 im 4-Bit-Modus. Das re...
by ghp
Tue Aug 27, 2013 6:32 pm
Forum: Deutsch
Topic: Endlos-Login
Replies: 4
Views: 1900

Re: Endlos-Login

Hallo, hatte mal einen ähnlichen Fall, bei dem eine Datei /etc/nologin durch ein zu schnelles Ausschalten nach shutdown liegen blieb. Diese Datei verhindert erfolgreich ein neues Einloggen. Um das zu prüfen: über pi einloggen per ssh (putty von windows aus, oder ssh von linux,unix,osx). Wenn diese D...
by ghp
Thu Aug 22, 2013 9:39 pm
Forum: Deutsch
Topic: Stromkreise und GPIO´s
Replies: 10
Views: 4044

Re: Stromkreise und GPIO´s

Hallo, Du kannst auch Schottkydioden am Eingang zusammen mit Vorwiderständen verwenden. Vorwiderstand 1kOhm, dann Schottky in Sperrichtung zu plus 3V3 und eine weitere zu Masse, auch in Sperrichtung. 'Clamp-Schaltung'. Wenn die Eingangsspannung grösser 3.3V wird, oder kleiner als Masse, dann leitet ...
by ghp
Thu Aug 22, 2013 9:29 pm
Forum: Deutsch
Topic: ras gertboard - kann mir jemand helfen
Replies: 3
Views: 1030

Re: ras gertboard - kann mir jemand helfen

Hallo, das Gertboard hat einen Darlingtontreiber ULN2803-Chip, der 500mA schalten kann. Das bedeutet: J6, 1--> Spannungsversorgung für Ventilator, plus J6, 0--> Spannungsversorgung für Ventilator, Masse J12, 1, Ventilator plus J12, 2, Ventilator minus J4, Pin 1, RELAY_1 mit GPIO <N z.B. 10> verbinde...
by ghp
Sat Aug 10, 2013 5:56 pm
Forum: General discussion
Topic: Controlling a 7 segment display
Replies: 2
Views: 3959

Re: Controlling a 7 segment display

Hello, think it should be possible to use this device from a raspberry. Although arduino world is using 5V, the module uses only inputs, so the raspberry 3.3V will drive the device, but there are no 5Voutputs which would harm the pi. I do not have a complete solution, but here is a sketch for this: ...
by ghp
Sat Aug 10, 2013 4:03 pm
Forum: Python
Topic: GPIO No errors but not working
Replies: 7
Views: 2037

Re: GPIO No errors but not working

Hello, think you ran into the pin numbering problem: GPIO.BOARD uses the P1-Header-Pin-Number. GPIO.BCM uses the controller's internal numbers. Your code is 'BOARD' Pin 7, which is the BCM GPIO4-Pin. When I run the code, this pin is changing in the intended way. Greetings Gerhard Checklist: - root p...
by ghp
Sat Aug 10, 2013 10:04 am
Forum: Deutsch
Topic: Problem mit Schalter
Replies: 3
Views: 1645

Re: Problem mit Schalter

Hallo, habe Deinen Code mal ausprobiert. Habe keinen Schalter angeschlossen, sondern ein Stück Draht gegen Masse verwendet. Hier sehe ich auch das Verhalten, dass beim Schliessen und Öffnen jeweils der Callback ausgelöst wird. Bei 500ms debounce-Time funktioniert das dann recht zuverlässig, allerdin...
by ghp
Thu Aug 08, 2013 10:58 am
Forum: Deutsch
Topic: Erfahrungsberichte mit Relais 230V
Replies: 11
Views: 22311

Re: Erfahrungsberichte mit Relais 230V

Hallo, Ansteuerung mit Transistor mit 1k BasisWiderstand. Oder einen ULN2803 für ein paar mehr Kanäle. Habe seit einiger Zeit auch so ein Teil (nicht genau dasselbe) bei mir liegen und mal die Strom/Spannung am Eingang angesehen: der Strom war relativ konstant über den gesamten Spannungsbereich von ...
by ghp
Tue Aug 06, 2013 4:50 am
Forum: Deutsch
Topic: Temperatur/Luftfeuchtigkeit über Funk?
Replies: 9
Views: 20097

Re: Temperatur/Luftfeuchtigkeit über Funk?

Hallo, zigbee module sind u.U. eine Lösung. Zum Pi hin eine serielle Verbindung, entweder plain ascii oder eine api-implementierung. Hier gibt es Unterstützung in C oder java. Die Module sind für home-Automation entwickelt. Die Module haben digitale EA, und können auch Analog einlesen. Sendeleistung...
by ghp
Mon Aug 05, 2013 6:42 pm
Forum: Python
Topic: Stop continuous thread
Replies: 3
Views: 1423

Re: Stop continuous thread

Hello, python threads do not react to keyboard interrupts. You need to handle signals in main thread, ant then use a 'variable' to send a stop-signal to your thread. Example, just a sketch def Stepper(threading.Thread): runIt = None def __init__(self): runIt = True ... def run(self): while ( runIt )...
by ghp
Mon Aug 05, 2013 6:31 pm
Forum: Python
Topic: How to run a python or bash command from Apache
Replies: 4
Views: 1921

Re: How to run a python or bash command from Apache

Hello, you cannot run arbitary python scripts directly from apache, unless 'arbitary' is a subset of CGI-script. Apache can call CGI-Scripts written in python (or other languages). Google for 'python CGI', and you will find a world of tutorials. Your cgi-python-script can then call an 'arbitary' scr...
by ghp
Mon Jul 29, 2013 8:10 pm
Forum: Python
Topic: PHP->Python or is there a better method?
Replies: 3
Views: 1560

Re: PHP->Python or is there a better method?

Hello, php for the web interface, and python for backend gpio access. In between could be a plain socket conection. If you build the command in 'readable ascii', you can test the backend module with a telnet session. I have build a similiar project with python in the web front end. The advantages ar...
by ghp
Mon Jul 29, 2013 5:07 am
Forum: Python
Topic: Strings, lists and tuples muddle!
Replies: 9
Views: 1467

Re: Strings, lists and tuples muddle!

Gratulation !

You have used your knowledge to solve a problem. And reading in data structures simply by using "eval" is a pythonic solution and a nice point.
Good luck in further studies !

Gerhard
by ghp
Sun Jul 28, 2013 5:41 pm
Forum: Python
Topic: Help! Syntax error!!
Replies: 3
Views: 664

Re: Help! Syntax error!!

Hello, I assume, that you want to run the hello world as a python code, and in the console you first start python, and then you enter the "print "hello world"". When you start python interpreter, check the version information printed. (the following is from my system) pi@raspberrypi ~ $ python Pytho...
by ghp
Sun Jul 28, 2013 5:33 pm
Forum: Python
Topic: Strings, lists and tuples muddle!
Replies: 9
Views: 1467

Re: Strings, lists and tuples muddle!

I have choosen the dictionary, as your first code snippet was having three individual variables. When you read these in again, your code should be able to separate them easily. Dictionaries are a simple way to achieve this: flagc1 = theDictReadInFromJson['flagc1'] Lists will work similiar. The seque...
by ghp
Sun Jul 28, 2013 4:25 pm
Forum: Python
Topic: Strings, lists and tuples muddle!
Replies: 9
Views: 1467

Re: Strings, lists and tuples muddle!

Hello, for the storage of structured data, json is good choice. import json flagc1 = [1,25,[255,0,0],"Tartan Red"] flagc2 = [2,25,[0,255,0],"Green"] flagc3 = [3,25,[36,34,87],"Dark Blue"] data = { } data ['flagc1'] = flagc1 data ['flagc2'] = flagc2 data ['flagc3'] = flagc3 print(json.dumps(d)) # # r...
by ghp
Fri Jul 26, 2013 6:26 pm
Forum: Python
Topic: Using RPi.GPIO
Replies: 20
Views: 2929

Re: Using RPi.GPIO

usually by

apt-get update
apt-get upgrade -y

which will bring all of your modules to newest state. May last a while
by ghp
Fri Jul 26, 2013 3:56 pm
Forum: Python
Topic: Using RPi.GPIO
Replies: 20
Views: 2929

Re: Using RPi.GPIO

Hello, have a look to http://elinux.org/RPi_Low-level_peripherals#General_Purpose_Input.2FOutput_.28GPIO.29 The numbering schemes are BOARD (pin numbers of the header) or according to the ARM-Chip BCM. I prefer the later. Not each of the BCM-chips es exposed., and some are occupied by serial line at...
by ghp
Wed Jul 24, 2013 6:11 pm
Forum: Troubleshooting
Topic: Client Server
Replies: 1
Views: 305

Re: Client Server

Hello, I would like to help, but I do not like to spend a lot of time in viewing a lengthy video. Pls post client and server code, this would help. Could be, that ip-addresses are not valid. On Laptop (Server, Windows?) use ipconfig to find out current ipAddress. On pi(== client), ping the laptop: i...
by ghp
Mon Jul 22, 2013 3:04 pm
Forum: HATs and other add-ons
Topic: SPI between Pi and GB
Replies: 9
Views: 4003

Re: SPI between Pi and GB

Hello, speed is not only a question on how fast the hardware can run, but also a matter on how fast the spi-handling code on 328 is performing. I have build a project, using SPI to an 328. It uses some 20 different commands and a few of them returning values from the 328 to the Pi. When looking to t...

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