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power [2016/06/20 02:26] admin [HDMI] |
power [2016/06/20 03:47] (current) admin [WiFi & Bluetooth] |
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| ===== Reduce Power Consumption ===== | ===== Reduce Power Consumption ===== | ||
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| This article assumes we're working on any //Raspberry Pi Model B//, fully equipped with network adapter, USB ports and HDMI. //Pi Zero// and //Model A// are already built in such ways that their power consumption is much lower than Model Bs. | This article assumes we're working on any //Raspberry Pi Model B//, fully equipped with network adapter, USB ports and HDMI. //Pi Zero// and //Model A// are already built in such ways that their power consumption is much lower than Model Bs. | ||
| + | Also note that most of the following commands **should be run as root**, so whether login as root on systems that allows it or use **''su root''** to operate as root. | ||
| ==== Network and USB adapters ==== | ==== Network and USB adapters ==== | ||
| The power hungry monsters in the Raspberry Pi are certainly the USB and Network Adapters. They were reported to consume as much as 200mA! Turning them off will enhance the system's autonomy when running off a power bank. | The power hungry monsters in the Raspberry Pi are certainly the USB and Network Adapters. They were reported to consume as much as 200mA! Turning them off will enhance the system's autonomy when running off a power bank. | ||
| - | === USB === | + | === USB (+ Ethernet) === |
| - | To switch the USB bus on a RasPi one can use the following commands: | + | To **switch off the USB bus** on a RasPi, which will in effect **also switch off the Ethernet** port that is linked to this same bus, one can use the following commands: |
| <Code:bash |**Turn off USB** on the Raspberry Pi:> | <Code:bash |**Turn off USB** on the Raspberry Pi:> | ||
| > echo 0x0 > /sys/devices/platform/bcm2708_usb/buspower | > echo 0x0 > /sys/devices/platform/bcm2708_usb/buspower | ||
| Line 86: | Line 86: | ||
| </Code> | </Code> | ||
| - | To turn HDMI back on, you'll want to know what GROUP, MODE & DRIVE to use, to discover the available modes in each group use the ''/opt/vc/tvservice'' command with the following options: | + | To **turn HDMI back on**, you'll need to have the **''kbd''** package installed to access and use the ''chvt'' command: |
| - | <Code:bash |Video Groups Modes> | + | <Code:bash |Turn HDMI back on> |
| - | > /opt/vc/bin/tvservice --modes=CEA | + | > /opt/vc/bin/tvservice -p && chvt 1 && chvt 7 |
| - | Group CEA has 7 modes: | + | |
| - | mode 1: 640x480 @ 60Hz 4:3, clock:25MHz progressive | + | |
| - | mode 2: 720x480 @ 60Hz 4:3, clock:27MHz progressive | + | |
| - | mode 3: 720x480 @ 60Hz 16:9, clock:27MHz progressive | + | |
| - | (native) mode 4: 1280x720 @ 60Hz 16:9, clock:74MHz progressive | + | |
| - | mode 17: 720x576 @ 50Hz 4:3, clock:27MHz progressive | + | |
| - | mode 18: 720x576 @ 50Hz 16:9, clock:27MHz progressive | + | |
| - | mode 19: 1280x720 @ 50Hz 16:9, clock:74MHz progressive | + | |
| - | > /opt/vc/bin/tvservice --modes=DMT | + | |
| - | Group DMT has 10 modes: | + | |
| - | mode 4: 640x480 @ 60Hz 4:3, clock:25MHz progressive | + | |
| - | mode 5: 640x480 @ 72Hz 4:3, clock:31MHz progressive | + | |
| - | mode 6: 640x480 @ 75Hz 4:3, clock:31MHz progressive | + | |
| - | mode 8: 800x600 @ 56Hz 4:3, clock:36MHz progressive | + | |
| - | mode 9: 800x600 @ 60Hz 4:3, clock:40MHz progressive | + | |
| - | mode 10: 800x600 @ 72Hz 4:3, clock:50MHz progressive | + | |
| - | mode 11: 800x600 @ 75Hz 4:3, clock:49MHz progressive | + | |
| - | (prefer) mode 16: 1024x768 @ 60Hz 4:3, clock:65MHz progressive | + | |
| - | mode 17: 1024x768 @ 70Hz 4:3, clock:75MHz progressive | + | |
| - | mode 18: 1024x768 @ 75Hz 4:3, clock:78MHz progressive | + | |
| </Code> | </Code> | ||
| - | So when you want to turn the HDMI back on with, lets say, a 1024x768@60Hz screen: | + | ==== WiFi & Bluetooth ==== |
| - | <Code:bash | Turning HDMI back on at a specific resolution> | + | https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=138610 |
| - | > /opt/vc/bin/tvservice -e="DMT 16 HDMI" | + | |
| - | </Code> | + | http://www.mikeslab.net/?p=455 |
