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

midwesternmac.com

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

#21

Post by teraflop »

markbao wrote: post #12

That's really cool - with those settings, you could run it on a single charge of one of those cheap 20,000 mAh portable batteries for a month.

It might require a bit of hardware hacking to get that to work. I have one of those battery packs, and according to the manual, it will shut off automatically when the output current drops below 50mA.

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

#22

Post by ssalazar »

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…

Depending on your requirements a powered USB hub could solve your problems quite nicely.

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

#24

Post by robzyb »

chatman wrote: post #23

Why are you referring to the units of mA for "power", as opposed to current draw? The power consumed would be measured in watts or milliwatts.

The Raspberry Pi runs on a fixed 5 volts. At a fixed voltage power will scale linearly with current.

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

#25

Post by janjongboom »

Why are we even using a Raspberry Pi for battery powered projects... 30 mA draw is so high you'll be changing batteries every 2 days, and that is without doing anything. Compare that to f.e. a normal phone chipset with deep sleep, which draws about 9 mA with a cellular connection, or .1-.2 mA in flight mode.

Or, if you just use the Pi for sensor readings, get a proper microcontroller, where current is measured in micro (or even nano-)amps...

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

#26

Post by agumonkey »

janjongboom wrote: post #25

Why are we even using a Raspberry Pi for battery powered projects... 30 mA draw is so high you'll be changing batteries every 2 days, and that is without doing anything. Compare that to f.e. a normal phone chipset with deep sleep, which draws about 9 mA with a cellular connection, or .1-.2 mA in flight mode. Or, if you just use the Pi for sensor readings, get a proper microcontroller, where current is measured in mic…

But are these phone chip application-class or domain specific ones ? meaning you can leverage linux ecosystem or do you have to program on their ~OS ?

I was looking for the most power efficient thing that could run a minimal desktop on battery and fit into my palm.

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

#27

Post by lucaspiller »

janjongboom wrote: post #25

Why are we even using a Raspberry Pi for battery powered projects... 30 mA draw is so high you'll be changing batteries every 2 days, and that is without doing anything. Compare that to f.e. a normal phone chipset with deep sleep, which draws about 9 mA with a cellular connection, or .1-.2 mA in flight mode. Or, if you just use the Pi for sensor readings, get a proper microcontroller, where current is measured in mic…

At this rate it's not far off what you would get with an ATtiny while active, which consumes around 10mA[0], the difference is that those and other micro controllers have sleep modes which reduce the consumption into the uA range - hopefully details on something like that for the Pi will be released too.

[0] https://learn.sparkfun.com/tutorials/h2ohno/low-power-attiny

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

#28

Post by Andrenid »

janjongboom wrote: post #25

Why are we even using a Raspberry Pi for battery powered projects... 30 mA draw is so high you'll be changing batteries every 2 days, and that is without doing anything. Compare that to f.e. a normal phone chipset with deep sleep, which draws about 9 mA with a cellular connection, or .1-.2 mA in flight mode. Or, if you just use the Pi for sensor readings, get a proper microcontroller, where current is measured in mic…

For someone like me who has only just started playing with microcontrollers thanks to the Arduino and RasPi and has never touched/played with anything else.. could you give any suggestions/links on what I should consider using for sensors?

I have a bunch of "nodes" I need to make, each one has a single sensor (temperature, moisture, light, or distance using a sonic sensor) that will send back to a Raspberry Pi base station. I was going to use RasPi's for all of them since it's all I know. Each will be battery powered with a solar panel. Open to any/all suggestions people can give me on how best to attack this!

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

#30

Post by joosters »

Does the PI have any kind of 'deep sleep' support? If you could put the system into something like ACPI S3/S4 sleep state (suspend to RAM) and make it periodically wake up every n seconds, you might be able to save a lot more power. The PI would still be usable for many tasks, e.g. data sampling every few seconds.
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