Has anyone tried powering the Raspberry PI running Rasplex with power coming from the USB port on the TV? I have read various things about this, with some issues:
- not enough power for some applications.
- how to control the behaviour of the power to the USB port when the TV switches off to prevent the raspberry being power cycled and corrupting the SD card.
It seems like a good solution in comparison to having another wall-wart power-supply, but curious if anyone has implemented this, and what they think of it?
Thanks Calby - What behaviour does your TV do when you switch off the TV via remote? I guess the USB port continues to provide power to the Pi, or do you have to shut down the Pi before you shut down the TV?
I am going to do some tests with the voltmeter this weekend to see what the USB port on the TV does when the TV is switched off (into standby) as this will determine if it's going to work well or not.
I tried this with a pi on a 2012 Samsung model which has 2 usb ports; a low power and a high power port. Unfortunately the power to both ports is cut when powering off the TV. I would rather have the pi powered on permanently (even with the TV off) to prevent possible damage to the pi / SD card.
I tried this with a pi on a 2012 Samsung model which has 2 usb ports; a low power and a high power port. Unfortunately the power to both ports is cut when powering off the TV. I would rather have the pi powered on permanently (even with the TV off) to prevent possible damage to the pi / SD card.
That was my concern - someone turns the TV off with the remote, and it simply kills power to the Pi and risks corruption. Ideal would be some macro on the remote that powers down the PI THEN turns off the TV, or some firmware on the TV that ensures the power to the USB port is always on while TV is in standby mode.
That was my concern - someone turns the TV off with the remote, and it simply kills power to the Pi and risks corruption. Ideal would be some macro on the remote that powers down the PI THEN turns off the TV, or some firmware on the TV that ensures the power to the USB port is always on while TV is in standby mode.
I examined some more of the menu items on my Samsung TV this afternoon and unfortunately there is no setting that I could find that would allow the USB ports to remain powered after the TV shuts off. You can use the HDMI-CEC settings in Plexbmc to shut down the pi when you power off the tv, but this process doesn't have a chance of completing in the second or two after you press the power button when the TV still provides juice to the pi.
Now if you had some sort of capacitor between the pi and the TV's USB port that would provide 5 - 10 seconds of power to the pi allowing it to shutdown.. that would be sweet!
I am also using the PI powered of the tv usb port , so far so good.
Mine is powered by the USB port successfully, and switches on with the TV in stadby mode with the TV remote control, however, when it comes to shutting it down, I have to shut down the Rasplex application THEN switch off the TV or it simply powers off. I take it you just always switch off the Rasplex before switching off the TV? This is fine if I was the only user, but guests visiting won´t know about this or remember it necessarily, and the opportunity for a corrupted SD card is just too great to risk.
Now, if there is someway to edit the CEC config to send a shutdown command to the Rasplex when the TV remote control off button is used, this would probably work well. The power to the USB on my Samsung TV stays on for a couple of seconds after the TV has switched off, which could be time enough to shut down Rasplex properly, as it does shutdown very fast. The ideal would be someway of configuring the remote so that when you power off the TV, it sends a shutdown command to Rasplex, then adds a delay of x seconds (configurable depending on how long Rasplex takes to shut down) before sending the command to shutdown the TV. This is easily achievable with something like a Harmony remote, but that then defeats the whole objective of using the CEC functionality, as well as adding the extra cost to each Rasplex installation (I am looking at 8+ in total, so don´t really want to buy another 8 Harmony remotes.
So the question is, how configurable are the CEC settings, if at all?
So, doing some further research and reading this post http://forum.xbmc.org/showthread.php?tid=170538 which relates to XBMC, it seems to be that if you can edit a remote control config file, there is a way to solve this. The power button on a remote is possibly not mapped in Rasplex, but if I could map that to issue the shutdown command, the CEC standards seem to suggest that this can then trigger a TV shutdown command also. Effectively, the shutdown button when received through CEC would shutdown Rasplex, and in shutting down Rasplex, this would then shutdown the TV afterwards (and then kills USB power). However, the problem I see is the following scenario:
When I power on the TV now, it powers up the USB port on the TV and boots the Rasplex, even if I am only watching TV. If I then go to shutdown the TV when not using the HDMI Source that Rasplex is connected to, the command to shutdown Rasplex won't be sent, and therefore the TV will simply shutdown as usual, killing the power.
So - the challenge is finding someway that the Rasplex can be left connected to the USB port all the time, and the shutdown commands and subsequent TV shutdown can happen regardless of wether the TV is being used for Rasplex Source Port, or TV/DVD/Cable Box input source.
Old thread, but for anyone looking at this, I think I have found the perfect solution - yet to try it though. There are now a number of UPS available for the Raspberry Pi, that will do a FSSD when power is disconnected i.e. a safe-shutdown. The most interesting I have seen is the UPS PiCo http://www.pimodules.com/_pdf/UPS_PIco_Final_PiMMP-R6.pdf which runs a rechargeable 300mAh LiPO battery specially designed to enable safe shutdown during a power cut, or in my case, when the power coming from the USB port on the TV is switched off.
Has anyone tried this? If so, this looks like it could make the Pi (or Pi2 as I am using now) the perfect Plex client. The Pi needs only a wifi adapter, an HDMI cable to the TV and a USB cable to the USB port on the TV and it becomes a very small and tidy solution to hang with velcro on the back of the screen.
Old thread, but for anyone looking at this, I think I have found the perfect solution - yet to try it though. There are now a number of UPS available for the Raspberry Pi, that will do a FSSD when power is disconnected i.e. a safe-shutdown. The most interesting I have seen is the UPS PiCo http://www.pimodules.com/_pdf/UPS_PIco_Final_PiMMP-R6.pdf which runs a rechargeable 300mAh LiPO battery specially designed to enable safe shutdown during a power cut, or in my case, when the power coming from the USB port on the TV is switched off.
Has anyone tried this? If so, this looks like it could make the Pi (or Pi2 as I am using now) the perfect Plex client. The Pi needs only a wifi adapter, an HDMI cable to the TV and a USB cable to the USB port on the TV and it becomes a very small and tidy solution to hang with velcro on the back of the screen.
Sounds interesting, I've not yet tested powering the pi2 off my Samsung TV so I'm not sure it has the juice required in the first place! Must test soon.
Sounds interesting, I've not yet tested powering the pi2 off my Samsung TV so I'm not sure it has the juice required in the first place! Must test soon.
Good point - I only tried my Pi Model B and have not looked at the increased draw for a Pi 2. Fingers crossed!
I have the Pi Model B and it powers up and works from my Toshiba's USB port (no idea what model, its bolted to the wall and I CBF) It's new enough to have "REGZA" aka CEC, and its also possible to play music and see photos off usb flash drives plugged in (though not 2.5" HDD's) so it might have a little more power than usual.
BUT, I don't use that port to run my Pi, as I like to turn my TV on and off with my Pi, when the TV turns off it kills power to the USB and the Pi stops responding, so it is not ideal for my purposes.
If I turn the TV on whilst the Pi is powering from the TV USB port it also steals the screen after it boots if I happen to be wanting to watch normal TV. (I realize this is configurable, but again CBF)
I run mine off the USB port in the back of my router which lives on the wall next to the TV and is always on, I find this to be the most convenient for my purposes.
