Using modern 'smart' USB Power Adapters with Raspberry Pi? - Raspberry Pi Forums
pi / pi 2 using modern 'smart' usb power adapters supply power raspberry?
once upon time there 1 way charge usb device , done @ 5v , 500ma max, or i've been told.
'modern' usb power adapters apple 1amp, 2amp , 2.4amp , many samsung chargers used tablets use way of 'negotiating' higher power draws (anything above 500ma presume) via resistors or other 'smart' circuit on d+ , d- (the data ports of usb cable).
have couple of ipad chargers both 10w (5v, 2amp) , 12w (5v, 2.4amp) models , tried use them on raspberry pi 2. surprised notice pi's red power led blinking time, plus 'pulsing colored square in top right of screen' (apparently newer firmware way alert insufficient current) going on , off when used pi 2 compile something.
there no question of faulty components, have 3 pi 2s exhibiting same behavior on apple chargers. conclusion pi can't use these 'smart' chargers , talk them via d+, d- data ports 'negotiate' more power , kept on short leash.
there 3 usb port charger ikea has on sale (so new websites don't have it) http://www.ikea.is/products/38976 has max of 2.4amps on each port 3.4amp total fails work pi 2 in same fashion.
case? pi need 'classic' (non-smart) power supplies give 'all they've got' without asking questions?
if so, there way mod pi tell these 'smart' chargers give more power? (heard shorting d+, d- pin on pi achieve or 'smarter' solution of adding right resistors ports manually choose 1 of these 'smart'er modes.
ps. internet full of articles on how mod 'dumb' power supply use in 'modern' devices, none on how use classic devices need more power 'modern' 'smart' chargers behave in way.
once upon time there 1 way charge usb device , done @ 5v , 500ma max, or i've been told.
'modern' usb power adapters apple 1amp, 2amp , 2.4amp , many samsung chargers used tablets use way of 'negotiating' higher power draws (anything above 500ma presume) via resistors or other 'smart' circuit on d+ , d- (the data ports of usb cable).
have couple of ipad chargers both 10w (5v, 2amp) , 12w (5v, 2.4amp) models , tried use them on raspberry pi 2. surprised notice pi's red power led blinking time, plus 'pulsing colored square in top right of screen' (apparently newer firmware way alert insufficient current) going on , off when used pi 2 compile something.
there no question of faulty components, have 3 pi 2s exhibiting same behavior on apple chargers. conclusion pi can't use these 'smart' chargers , talk them via d+, d- data ports 'negotiate' more power , kept on short leash.
there 3 usb port charger ikea has on sale (so new websites don't have it) http://www.ikea.is/products/38976 has max of 2.4amps on each port 3.4amp total fails work pi 2 in same fashion.
case? pi need 'classic' (non-smart) power supplies give 'all they've got' without asking questions?
if so, there way mod pi tell these 'smart' chargers give more power? (heard shorting d+, d- pin on pi achieve or 'smarter' solution of adding right resistors ports manually choose 1 of these 'smart'er modes.
ps. internet full of articles on how mod 'dumb' power supply use in 'modern' devices, none on how use classic devices need more power 'modern' 'smart' chargers behave in way.
all rpis don't have data lines on micro usb power connector.
raspberrypi
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