Hi,

I've started designing a device for an outdoor installation. The plan is for around 20 such devices to be installed and, in some locations, battery operation will be the only option. My first observation using the Bela is that is uses approximately 200mA in the idle state and around 300mA once the project is running. Should I expect the same if using the Bela mini?

I've searched this forum for "low power" and "sleep" modes and haven't found much information. Is there any way to put a real time system such as Bela into a low power or standby mode after a certain time of inactivity? Ideally maintaining certain peripherals active so Bela can be awakened when a user manifests itself.

Thanks!

I though it's more around 400mA at 5V ... how are you measuring it ?

Sorry I meant 200-300mA measured using a cheap USB power meter. Probably not very precise. I'll connect it through a real amp meter eventually to confirm this reading.

When using the mini multi channel expander however it was indeed closer to 400mA.

So no lower power or sleep modes exist then I guess?

Thanks!

    tohox Sorry I meant 200-300mA measured using a cheap USB power meter. Probably not very precise. I'll connect it through a real amp meter eventually to confirm this reading.

    I think what you are measuring may well be right. I haven't measured those in such a long time, but I remember recommending 500mA for power supplies, so measuring 280mA seems about right.

    The only way to lower the power consumption is by turning down the CPU clock. That has to be done on uboot (i.e.: before Linux is started) because Xenomai 3 doesn't allow CPU frequency changes while the board is running . That's not straightforward, but was done at some point: https://forum.bela.io/d/688-changing-cpu-frequency/13

      4 days later

      FWIW, my Juwei USB power measuring tool measures between 350 mA and 410 mA when running a program and a bit less (around 310mAh) at idle on a BelaRevC. This is more in line with what I remembered obtaining years ago with a multimeter.

      The BelaMini seems to be a bit lower, I think I read around 210mA.