the low wattage of a midi socket, as for midi norms, is enough to power a bluetooth dongle but not enough to power a tablet or smartphone connected to the midi socket with a midi-usb adapter.
since a midi-usb "cable" actually consists in two half cables with a sort of converter between them, and the midi protocol uses only the data pins of the outgoing usb cable, if i wire the "power" pins of the usb cable out of the adapter pcb to a powerbank would the smartphone work?
at the usb end the cable will carry the midi messages thru the usb port data pins and enough wattage to power the tablet/smartphone while playing
thank you.
note: i'm trying to cut out all i can to avoid the "Sorry, but the system detected your content as spam", i hope i win sooner or later.
I WON! FINALLY!
Hello,
Would using a powered USB hub not help?
Regarding your problem posting, I've made a LOT of posts here, and had this problem a couple of times ONLY. One of the things that MIGHT be to blame could be the use of numerous links in your post, ESPECIALLY if it's your first post, and if there's a LOT of links relative to the actual message.
I don't know what was in your original post, but I suspect that if I saw it, I'd know what the problem was!
We have a constant fight here with non-midi postings.
Geoff
The USB MIDI protocol (and all other USB communication) uses all four pins.
But it is certainly possible to use USB to power devices. Please note that nowadays, many USB ports limit the current that is available; it might be safer to take power from another port, or from multiple ports.