Raspberry Pi Zero – Conserve power and reduce draw to 30mA • Hacker News Board

Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#1

Post by geerlingguy » Mon, Nov 30, 2015, 2:56 AM UTC

Raspberry Pi Zero – Conserve power and reduce draw to 30mA
midwesternmac.com

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#2

Post by geerlingguy » Mon, Nov 30, 2015, 2:58 AM UTC

After posting a comparison of power consumption of the Pi Zero vs other Raspberry Pis a couple days ago, I spent another couple hours today testing various methods of reducing power consumption, and was able to get the idle power usage down to about 25-30 mA on the Pi Zero!

Thanks to a few suggestions from others on the Raspberry Pi forums, Hacker News, and Reddit, I am able to disable the ACT LED and HDMI, and that results in a 5 mA and 30 mA savings, respectively.

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#3

Post by detaro » Mon, Nov 30, 2015, 3:02 AM UTC

geerlingguy wrote: post #2

After posting a comparison of power consumption of the Pi Zero vs other Raspberry Pis a couple days ago, I spent another couple hours today testing various methods of reducing power consumption, and was able to get the idle power usage down to about 25-30 mA on the Pi Zero! Thanks to a few suggestions from others on the Raspberry Pi forums, Hacker News, and Reddit, I am able to disable the ACT LED and HDMI, and that…

Does it have something in the way of sleep states, outside of being shut down?

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#4

Post by geerlingguy » Mon, Nov 30, 2015, 3:05 AM UTC

detaro wrote: post #3

geerlingguy wrote: post #2

After posting a comparison of power consumption of the Pi Zero vs other Raspberry Pis a couple days ago, I spent another couple hours today testing various methods of reducing power consumption, and was able to get the idle power usage down to about 25-30 mA on the Pi Zero! Thanks to a few suggestions from others on the Raspberry Pi forums, Hacker News, and Reddit, I am able to disable the ACT LED and HDMI, and that…

Does it have something in the way of sleep states, outside of being shut down?

This is another thing I've been investigating, and so far I've come up dry. I really wish there were some way of scheduling it to go into a sleep state, and wake up every 30s or every minute, something like that... you'd think the mobile processor would have some way of doing this, but so far all my searching has been fruitless :(

There are hardware add-ons like the Sleepy Pi[1], but that's a large added expense, and makes the management of the overall platform a lot more complicated.

[1] http://spellfoundry.com/products/sleepy-pi/

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#5

Post by kozukumi » Mon, Nov 30, 2015, 4:39 AM UTC

Anyone got any info on running a Zero with WiFi and a camera running off solar? I would love to build a ~£15-20 IP camera if possible.

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#6

Post by analog31 » Mon, Nov 30, 2015, 5:09 AM UTC

geerlingguy wrote: post #2

After posting a comparison of power consumption of the Pi Zero vs other Raspberry Pis a couple days ago, I spent another couple hours today testing various methods of reducing power consumption, and was able to get the idle power usage down to about 25-30 mA on the Pi Zero! Thanks to a few suggestions from others on the Raspberry Pi forums, Hacker News, and Reddit, I am able to disable the ACT LED and HDMI, and that…

How much of this applies to the bigger RPi models? Also, can you throttle the clock speed of the microprocessor and further reduce current consumption?

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#7

Post by newman314 » Mon, Nov 30, 2015, 5:09 AM UTC

geerlingguy wrote: post #2

After posting a comparison of power consumption of the Pi Zero vs other Raspberry Pis a couple days ago, I spent another couple hours today testing various methods of reducing power consumption, and was able to get the idle power usage down to about 25-30 mA on the Pi Zero! Thanks to a few suggestions from others on the Raspberry Pi forums, Hacker News, and Reddit, I am able to disable the ACT LED and HDMI, and that…

Can you try running things through powertop (follow the recommendations) and measure any possible differences?

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#8

Post by perlin » Mon, Nov 30, 2015, 5:27 AM UTC

We've actually found that the RPi doesn't draw enough power, specifically to the USB ports. Our peripherals are within the USB spec of a 500ma max pull, but even so we are experiencing sporadic CPU brownouts. The first thought was to double the max_usb_current in /boot/config.txt, but that only lengthened the time between brownouts. We looked into hacks that could increase the current even more, such as this bypass method: http://hackaday.com/2015/04/06/more-power-for-raspberry-pi-u.... Unfortunately, this isn't a viable solution as we continue to scale up our deploys. Some viable alternatives include switching to a board that supports USB3.0, underclocking the CPU, or doing a custom solution through Element14. I really wish the RPi was more stable around power / fault tolerances, but they're a blessing nonetheless :) [Plug]: If you're based in NYC, enjoy hacking hardware and find these types of problems to be delightful, please shoot me an email: mykola@colorcreative.io ;)

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#9

Post by lemevi » Mon, Nov 30, 2015, 5:31 AM UTC

perlin wrote: post #8

We've actually found that the RPi doesn't draw enough power, specifically to the USB ports. Our peripherals are within the USB spec of a 500ma max pull, but even so we are experiencing sporadic CPU brownouts. The first thought was to double the max_usb_current in /boot/config.txt, but that only lengthened the time between brownouts. We looked into hacks that could increase the current even more, such as this bypass m…

Have you tried a BeagleBone Black or any kind of BeagleBoard? What are you scaling RPi's for? Arduino and Raspberry pis strike me as toys compared to BBB's. BBBs are a lot less forgiving and require way more understanding of basic electronics to do anything with, even as simple as lighting an external LED will break your BBB if you didn't do it right, but they seem more powerful in terms of what you can do (although underpowered compared to Rasbperry Pi when it comes to video processing).

Re: Raspberry Pi Zero – Conserve power and reduce draw to 30mA

#10

Post by perlin » Mon, Nov 30, 2015, 5:43 AM UTC

lemevi wrote: post #9

perlin wrote: post #8

We've actually found that the RPi doesn't draw enough power, specifically to the USB ports. Our peripherals are within the USB spec of a 500ma max pull, but even so we are experiencing sporadic CPU brownouts. The first thought was to double the max_usb_current in /boot/config.txt, but that only lengthened the time between brownouts. We looked into hacks that could increase the current even more, such as this bypass m…

Have you tried a BeagleBone Black or any kind of BeagleBoard? What are you scaling RPi's for? Arduino and Raspberry pis strike me as toys compared to BBB's. BBBs are a lot less forgiving and require way more understanding of basic electronics to do anything with, even as simple as lighting an external LED will break your BBB if you didn't do it right, but they seem more powerful in terms of what you can do (although…

I have plenty of experience frying BBBs while trying to make LEDs blink ;) http://colorcreative.io/portfolio.html. The reason we use RPis in my place of work is due to USB peripheral support. I love the dedicated PRU in the BBB, though. It's perfect for the tight timing spec required by the WS281x LEDs :)