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power [2016/06/20 02:01] admin [Reduce Power Consumption] |
power [2016/06/20 03:47] (current) admin [WiFi & Bluetooth] |
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| ===== Reduce Power Consumption ===== | ===== Reduce Power Consumption ===== | ||
| - | ---- | ||
| 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 | ||
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| Referring to [[http://www.pidramble.com/wiki/benchmarks/power-consumption|this article concerning Raspberry's models power consumption]], we observe that HDMI and LED usage are using about 30 mA (for a RasPi 3). Another [[http://www.mikeslab.net/?p=455|interesting article about RasPi's power consumption]] states that turning off HDMI in a "headless" configuration saves about 20mA. | Referring to [[http://www.pidramble.com/wiki/benchmarks/power-consumption|this article concerning Raspberry's models power consumption]], we observe that HDMI and LED usage are using about 30 mA (for a RasPi 3). Another [[http://www.mikeslab.net/?p=455|interesting article about RasPi's power consumption]] states that turning off HDMI in a "headless" configuration saves about 20mA. | ||
| - | To turn off HDMI on the RasPi, simply issue this command: | + | To **turn off HDMI** on the RasPi, simply issue this command: |
| <Code:bash |**Turn off HDMI** on the RasPi:> | <Code:bash |**Turn off HDMI** on the RasPi:> | ||
| > sudo /opt/vc/bin/tvservice -o | > sudo /opt/vc/bin/tvservice -o | ||
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| Unfortunately this command won't survive a reboot, so if we known the system is going to be headless we should trigger this on each boot. | Unfortunately this command won't survive a reboot, so if we known the system is going to be headless we should trigger this on each boot. | ||
| + | |||
| + | <Code:bash |Create cron job running at startup to turn off HDMI> | ||
| + | TO BE COMPLETED | ||
| + | </Code> | ||
| + | |||
| + | To **turn HDMI back on**, you'll need to have the **''kbd''** package installed to access and use the ''chvt'' command: | ||
| + | <Code:bash |Turn HDMI back on> | ||
| + | > /opt/vc/bin/tvservice -p && chvt 1 && chvt 7 | ||
| + | </Code> | ||
| + | |||
| + | ==== WiFi & Bluetooth ==== | ||
| + | https://www.raspberrypi.org/forums/viewtopic.php?f=63&t=138610 | ||
| + | |||
| + | http://www.mikeslab.net/?p=455 | ||
