Sensors that do not draw any current or consume much power during sleep.

Other Hardware Sensors
1

I'm looking for sensor types that draw no current or consume extremely little power during sleep mode. Can you name a few?

I'm particularly interested in long distance sensor of over 20 feet.

2

you can use an Arduino IO pin to switch the powerline of the sensor. This makes it really energy friendly. sensors that draw little current can be controlled directly through an IO pin, otherwise you need a transistor/mosfet or so to switch it on.

Drawback is that it may take a bit more time before a first reading can be made.

long distance sensors ? wireless? wired? what type of sensor(s)

3

What is it that you want to sense? Does it need to sense anything when the microcontroller is in sleep mode?

4

Well, I was going to put together list of ultra low power sensors of different types for people looking to work with low power with the help of the community, but that just seems too confusing.

So, since I'm currently experimenting with long distance sensor such as ping parallax and ir sensor, I was wondering if any of you know of any long distance sensor that consumes extremely low power in the nanoAmps value, be they custom built or purchased.

My focus is really on ultra-low power sensors to clear any confusion.

5

I searched for low-power 38kHz IR sensors receivers a few days ago, and the lowest current consumption I found was 350uA. You won't find a ping sensor that takes very low power when active, because of the power needed to generate the ultrasonic pulse. However, you could design one that can be put into sleep mode and takes very little power in that state. There are op amps available that have a sleep input pin, e.g. MCP6283.

6

0.35mA is not bad. So if a company can't produce a long distance sensor lower than that, it seems to also mean that I'd probably be less likely to design a lower power than that. What do you mean putting it to sleep mode? What does it take to get it out of sleep mode if it's not able to read the distance in sleep mode?

7

There's a difference between powering down a distance sensor and having a sensor that automatically wakes up when it senses a new distance. The former can be done by driving the sensor's power line with an IO pin as previously suggested; the latter... I don't know of any distance sensors with a wakeup function.

8

kentc:
.....
My focus is really on ultra-low power sensors to clear any confusion.

I think you added to the confusion.

Do you want:

  • low power when measuring? (low power will often mean short range and high signal-noise ratio)
  • low power when in standby-mode, and then you power it up when it is time to measure?
  • sleep until it senses something, and then wake up and sense? (I agree with Chagrin that it sounds like magic)

An active sensor will have to ping its surroundings to sense anything, and sending out energy will consume energy.
In some cases you could power up, ping, power down and thus pay for a lower power consumption with a lower sample rate.

9
  • sleep until it senses something, and then wake up and sense? (I agree with Chagrin that it sounds like magic)

sleep and wake up every x seconds; make a measurement; not interesting? sleep again; else process it.