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What I would like to know more about is how to power these gadgets. Say I want a sensor that sends data to a server. Do I need to plug it into a power outlet? C

What I would like to know more about is how to power these gadgets. Say I want a sensor that sends data to a server. Do I need to plug it into a power outlet? Can I run it off a battery for a significant amount of time (months)? Can I use solar power? How much power does WiFi consume, or should I look into Bluetooth or ZigBee?

peter303 11y ago
Certain cellphone chargers. As little as $5 on Amazon. You can buy this in a kit too with common connector cords and simple peripherals like lights and motors.
teraflop 11y ago
> Can I run it off a battery for a significant amount of time (months)? Depends on how big a battery you're willing to use. In the other thread, someone claimed that the Pi Zero's typical power consumption is about 0.8 watts, so running it for a month would require about 600 watt-hours. That's roughly the energy content of one car battery, or ten Macbook batteries, or about 230 alkaline AAs. A USB wifi adapter would probably add another 0.5-1.0W. The Raspberry Pi isn't a great option for this kind of long-term low-power application, because it doesn't really have any power management capabilities to speak of. If you can get by with a low duty cycle, you could use additional components to wake up the Pi only when necessary. Less-powerful microcontrollers are more likely to have this functionality built in; for example, TI's Tiva series of ARM Cortex-M4F chips have a "hibernate" mode in which they can draw as little as 5 microwatts. > Can I use solar power? Again, it depends. A solar panel that can provide ~1W is not very large or expensive, but that's the rated output under direct sunlight. The actual power available could easily be 10x lower if it's cloudy, or 100x lower under very bright indoor lighting. And presumably you'll still want a battery and charging circuitry to keep things running at light or in low light. It's certainly doable, but the power supply will end up costing a lot more than the Pi itself.
- facepalm 11y ago
  Thanks!

peter303 11y ago

Certain cellphone chargers. As little as $5 on Amazon. You can buy this in a kit too with common connector cords and simple peripherals like lights and motors.

teraflop 11y ago

> Can I run it off a battery for a significant amount of time (months)? Depends on how big a battery you're willing to use. In the other thread, someone claimed that the Pi Zero's typical power consumption is about 0.8 watts, so running it for a month would require about 600 watt-hours. That's roughly the energy content of one car battery, or ten Macbook batteries, or about 230 alkaline AAs. A USB wifi adapter would probably add another 0.5-1.0W. The Raspberry Pi isn't a great option for this kind of long-term low-power application, because it doesn't really have any power management capabilities to speak of. If you can get by with a low duty cycle, you could use additional components to wake up the Pi only when necessary. Less-powerful microcontrollers are more likely to have this functionality built in; for example, TI's Tiva series of ARM Cortex-M4F chips have a "hibernate" mode in which they can draw as little as 5 microwatts. > Can I use solar power? Again, it depends. A solar panel that can provide ~1W is not very large or expensive, but that's the rated output under direct sunlight. The actual power available could easily be 10x lower if it's cloudy, or 100x lower under very bright indoor lighting. And presumably you'll still want a battery and charging circuitry to keep things running at light or in low light. It's certainly doable, but the power supply will end up costing a lot more than the Pi itself.

facepalm 11y ago
Thanks!