Hot answers tagged

78

No. The reason a DVI-to-VGA adapter works on your PC & laptop is that DVI includes analog (RGB) pins. The adapter is passive; It just connects the red analog output of the PC to the red analog input of the monitor, ditto for green and blue. They are included on most PCs and laptops for backward compatibility. HDMI-to-DVI cables are also passive, but ...


66

Sound does not work with an HDMI monitor This is caused by some computer monitors which select DVI mode even if an HDMI cable is connected. This fix may be necessary even if other HDMI devices work perfectly on the same monitor (or TV)! Edit the configuration file - see the instructions at Raspberry-Pi Configuration File. Add the following line to the ...


20

Simple! :) Buy TWO Raspberry Pies and hook them up with ethernet cable. Then use synergy to hook up the two systems in a virtual multihead config. See http://synergy-foss.org/ for more details. Apart from that - there's not much you can do now as hdmi & composite cannot be used simultaneously. This may change once we find out more about how to use the ...


16

The GPIO pins are 3.3 V, and the maximum current is 16 mA. That means you'll be unable to power almost anything directly. That's why you need to at least use a transistor switch, if not a more advanced protection circuit. You can read more about them in RPi Tutorial EGHS:GPIO Protection Circuits. A general guide is RPi Low-level peripherals.


12

I had a similar problem with my Pi, when I connected it first time to my tv (a Samsung D5000): the tv did not understand an HDMI device was connected. I have raspbmc as the os. There are a couple of instructions you can add to /boot/config.txt to tell your Pi to activate the hdmi output when you connect a cable, and to force hdmi output mode instead of dvi. ...


12

If you're using RPi.GPIO and run .cleanup() at the end of your script, it will return the channel(s) back to inputs with no pull up/down. Otherwise, they will remain in the state you left them. See https://sourceforge.net/p/raspberry-gpio-python/wiki/BasicUsage/ for details.


11

These instructions aren't Python-specific, but they might help you get started with experimenting with GPIO. https://raspberrypi.stackexchange.com/a/350/668 has info about a library and usage specific for Python. When you have booted your Raspberry Pi using the recommended Debian distro, GPIO is disabled. You have to enable each pin individually. If you'...


10

The issue was caused by the length of my HDMI cable which was 3M 1.4a HDMI spec. It is because the default power output on the HDMI connector is sometimes not enough for longer cables causing the zits, in order to fix this you should edit your config.txt file in the root of your SD card (will be visible under windows explorer, if the text file does not ...


10

Hackaday.com: USING CELL PHONE SCREENS WITH ANY HDMI INTERFACE http://hackaday.com/2014/11/02/using-cell-phone-screens-with-any-hdmi-interface/ Has a video specifically using a raspi and iphone 4 screen.


9

An active HDMI to VGA adapter would be much better quality than and active Composite video (RCA) to VGA adapter. Both would be much more expensive than a passive adapter however. Active HDMI to VGA adapters A quick check using google shopping suggests that an active HDMI to VGA adapter will cost around £50 ($80) and should support 1920x1080 resolution if ...


9

I also ran into the same problem with my Raspberry Pi 2. I connected my Pi to my HD TV via an HDMI cable. My solution: Set the audio output using the following command: amixer cset numid=3 2 I tested the sound output using the following command, but no sound was heard: speaker-test -c2 -t wav To enable HDMI sound, I followed the directions found here ...


9

I think I have a way for solving your problem, try to type omxplayer -o local xxx.mp3(for mp3 file) or omxplayer -o local xxx.mp4(for mp4 file) to hear sound from raspi over your headphone. And you can also type omxplayer --help for more usage about omxplayer.


9

It is doubtful that the connections from a cell phone LCD screen would be optimal to use with your Raspberry Pi. That said, I'm positive it's possible. But, why even go to the trouble? With multiple LCDs made specifically for the Raspberry Pi today (some of them touchscreens!), it is more practical to buy an LCD than to salvage one from a phone and use it....


8

Yes, that will work. I suggest you have something like a 1 kΩ resistor in series. That will limit the maximum current to 3.3 mA. That will save the day when by mistake you set both GPIOs as outputs, one as a 1 and the other as a 0. Without the resistor that would result in a damaging short circuit.


7

Yes, this is possible. You can achieve this by using a framebuffer driver from the fbtft project. According to the list of supported devices on the projects wiki, Nokia 5110/3310 displays are supported. These display modules are readily available on eBay.


6

If you know you won't be using the composite output, you can set up the pi to always use the hdmi output, even when no device has been detected. That way it will pick up the screen when it's attached, even if done at a later stage. In your config.txt add/change the following line: hdmi_force_hotplug=1 For more (screen and other) settings, see http://...


6

This seems to be a problem with the noob release - previous versions would default to the composite video if nothing was connected to the HDMI port. To correct this do the following: Connect your keyboard and TV to the Pi. Insert your SD card. Power on the TV. Power up the Pi and hold down the SHIFT key, until the green LED stops flickering This will ...


4

This is a common bug. I think what's breaking ALSA is PulseAudio. If you want to use ALSA (Default, recommend by Tux) use sudo apt-get remove PulseAudio For other fixes, try the wiki. It all depends. Try this first (as this is the most common)


4

I'm running OSMC, which runs Debian, and I got sound to play through my TV speakers, which is connected by HDMI. https://youtu.be/p2ljmTE67gs If this is what you're trying to do, try adding dtparam=audio=on to /boot/config.txt Original solution posted here: https://discourse.osmc.tv/t/alsa-doesnt-work-after-last-update/10600


4

At present I believe this to be a no-go: There are two outputs on the RPi - the hdmi and the composite, however the composite is turned off when hdmi is connected. You can get hdmi splitters, but that will just mirror the display on the two outputs, so if you're after that then fine.


4

The Neewer HDMI to VGA converter lead from Amazon does indeed work with the RPi but as has been reported elsewhere you have to do a bit of fine tuning in the /boot/config.txt file. I still cannot get my Samsung 943N to see anything but a simple Dell generic 15" VGA monitor works fine. One problem seems to be that the default output signal level is not ...


4

Per the elinux wiki, the GPIO pins are configurable to source or sink from 2mA to 16mA each, 3.3V (not 5V tolerant). They also have GPIO tutorials, one of which demonstrates driving a low power LED directly from the output with no 3.3V or 5V connection used.


4

It sounds like you need to add a pull up or pull down resistor to the cable causing your floating value. See http://en.wikipedia.org/wiki/Pull-up_resistor for more information.


4

The short answer is, no you can't do this with a Raspberry Pi. The long answer is, perhaps with enough external hardware and a great deal of knowledge of how HDMI works you might be able to do something like you describe. If you want to see and example of a hackable ARM device running linux that can do HDMI manipulation and pass through you can look at the ...


4

I am using the Audio jack prom a PI, with good result. Be aware that the quality of your power supply have profound effect on the quality of the audio from the PI. I the beginning I did not the this output as usable, as it was filled with noise, using a standard USB supply, for charging cell phones. I then got a Goobay charger, as tested on this page and ...


4

What finally helped was the following: I dumped the EDID-file with tvservice -d edid_dump.bin I edited this file with LIGHTWARE-EDID-editor (part of a demo suite). What I actually needed to change was little: In the CEA part of the file, I needed to specify that the device was HDMI-compliant (HDMI/HDMI options), and under CEA/Audio data, I needed to add ...


4

Edit the config.txt file The config.txt file is located in /boot directory. sudo nano /boot/config.txt Go to following line, and place # at start, if already not there: hdmi_force_hotplug=1 This will make the line like this: #hdmi_force_hotplug=1 Then save the file (Ctrl+o) and exit (Ctrl+x)


4

Possibly. If the gpio is at logic 1 it is already at 3V3 so there will be no difference. If the gpio is at logic 0 it is at ground and connecting 3V3 will in effect be a short-circuit. That can kill the gpio and or bank of gpios and or the Pi (unless an appropriate current limiting resistor is in place).


4

It depends on the module you are using and if you have changed the GPIO state using the module (rather than indirectly by calling a shell program to change the state). My pigpio leaves the GPIO in the last set state. I'm not sure about wiringPi (Python). RPi.GPIO and RPIO.GPIO both have a cleanup function. If that is called then any GPIO you have changed ...


3

The "simple" HDMI to VGA cables will not work quite simply because HDMI signals are pure digital and VGA is analogue. I made the mistake of buying a very cheap cable from Amazon which did not work for reasons that are clear to me now. I am awaiting the delivery of a "Neewer Black HDMI Input To VGA Adapter Converter For PC Laptop" from Amazon which I am ...


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