Raspberry Pi B+ USB Power: Difference between revisions
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The Raspberry Pi B+ and the Raspberry Pi 2 B+ by default is not configured to power a 2.5 inch self powering USB hard disk. By default the USB ports on the B+ and 2 B+ only allow USB power for about 400mA. A USB hard disks uses 600mA at a minimum. | |||
To increase the USB power to 1.2 amps | To increase the USB power to 1.2 amps | ||
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I believe this changes the gpio pin 38 value from 0 to 1 which opens a second resistor in parallel allowing for higher amperage over USB. | I believe this changes the gpio pin 38 value from 0 to 1 which opens a second resistor in parallel allowing for higher amperage over USB. | ||
'''NOTE''': A Raspberry Pi 3 uses 1.2 amps by default on the USB ports and does not require this setting. | |||
[[Category : Raspberry Pi]] | [[Category : Raspberry Pi]] | ||
Latest revision as of 09:54, 20 August 2016
The Raspberry Pi B+ and the Raspberry Pi 2 B+ by default is not configured to power a 2.5 inch self powering USB hard disk. By default the USB ports on the B+ and 2 B+ only allow USB power for about 400mA. A USB hard disks uses 600mA at a minimum.
To increase the USB power to 1.2 amps
vi /boot/config.txt
add the line
max_usb_current=1
I believe this changes the gpio pin 38 value from 0 to 1 which opens a second resistor in parallel allowing for higher amperage over USB.
NOTE: A Raspberry Pi 3 uses 1.2 amps by default on the USB ports and does not require this setting.
