7 ms·
i know nothing of electronics really, but doesn't the google chromecast get power over hdmi? maybe there's some way to do that with this hack?
by hayksaakian 11y ago
i know nothing of electronics really, but doesn't the google chromecast get power over hdmi? maybe there's some way to do that with this hack?
- agumonkey 11y agoAFAIK chromecast and other HDMI dongles have secondary USB port to get power.
- deleted 11y ago[deleted]
- GauntletWizard 11y agoIt's technically possible, but supported on so few devices it's not worth the extra circuitry, I assume.
- rzzzt 11y agoAccording to this Q&A, about 55-150 mA is available on a 5V line: http://www.hdmi.org/learningcenter/kb.aspx?c=13#42 http://www.hdmi.org/learningcenter/kb.aspx?c=13#42
- bduerst 11y agoYep - the chromecast pulls too much juice (up to 1A) for the HDMI power spec. 1A would be the sweet spot for future HDMI specs.
- agumonkey 11y agoOh I didn't know it was in spec. Also, it's just in range for a pi zero. How convenient.
- bduerst 11y agoThe USB-powered XBox controller is going to need another 300 mA. I also don't think the pi zero has a powerable HDMI adaptor.
- agumonkey 11y agoI had a pi zero hdmi dongle in mind without a supplementary usb cable.
- MiguelHudnandez 11y agoAn on-board battery or capacitor could help to smooth out brief high power tasks, but I don't think it will be able to sustain video decoding & playback at a constant supply of 150mA. I'm really excited for that to be a possibility though, so I hope I'm wrong. Of course, some TVs might dump a lot more current over the connection, just like what was common with USB 2.0 going well over 500mA.
- mikepavone 11y agoThat's on source devices, which in this case would be the Pi Zero. AFAIK, sink devices like a TV do not supply power.
- rzzzt 11y agoI somehow managed to miss the sentence entirely where this is explained (it is used for reading EDID from a connected display). Thanks for the correction!
- johnward 11y agoChromecast requires external power. Google's advertising of it is misleading.
- Spivak 11y agoEdit: I'm an idiot. You're right, I must have been thinking of CEC.
- moftz 11y agoI've never seen any Chromecast advertising that implies it only gets power over HDMI. All of the media on Google's Chromecast site show either both HDMI/Aux and USB plugged in or nothing plugged in. Pretty much any TV now has a USB port whether it be for media playback or for updating the firmware of the TV on older ones so its not a huge deal to have to plug it. Even the first release of the device clearly mentioned it needing USB power. https://www.youtube.com/watch?v=YRu18f2GRQo&t=41m22s https://www.youtube.com/watch?v=YRu18f2GRQo&t=41m22s
- johnward 11y agoAll of the screenshots I saw before purchasing the original device clearly showed it plugged into a TV with no power cord attached. It looks like they may have fixed it in the newer marketing.
- edent 11y agoNah. They rely on the fact that most modern TVs have a USB port near the HDMI ports. That usually provides enough juice.
- guyzero 11y agoMeaning power over HDMI is only provided when the TV supports MHL which most TVs don't support.
- CaptSpify 11y agoI know the rpi2 gets power over hdmi, not sure about the zero though