I am currently running an intel Edison on image 201606061707
I am trying to lower its power consumption for a length of time. I run the following using a shell file
iwconfig wlan0 power off
systemctl stop wpa_supplicant
echo -n "mem" > /sys/power/state
This lowers power consumption to 40 mah. I would like to get it lower, 30 mah is my target but even lower would be better. I am aware that I could use the "freeze" state to meet my goal, however, to my knowledge the only way to wake it from that state is with reset and I don't have that option. I currently use the mcu to wake the Edison using a timer in addition to a pin interrupt.
Is there anything I could turn off in addition to the wifi? Would I be able to increase power savings if I used bitbake to remove features from the image?
Thanks for your interest in the Intel Edison platform.
Besides that, we would like to suggest you to disable the Edison services you won't need, the Yocto image uses Systemd to manage the starting and stopping of services, so you could use # systemctl disable <.service> command to disable those services.
Additionally, if you remove the features from the Edison image you won't need using bitbake, it also could help with the power saving.
Hope this information helps, however, let us know if you have any questions.
We have been looking for that, and we have not found specific information regarding what services are in the Edison image, however, we found this general information regarding to https://freedesktop.org/wiki/Software/systemd/ systemd System and Service Manager, you may be interested in these sections: "The systemd for Administrators Blog Series" and "Manuals and Documentation for Users and Administrators" among others that have useful information.
Hope this information helps.
I have been systematically disabling services and monitoring power consumption. The power savings has been negligible, but it has greatly increased system instability. I have seen power drop to 4 or 6 mah, only to find out that the system had crashed do to disabling a service like the ofono.service. When the system doesn't crash, the power use remains the same during mem sleep give or take 2 mah. This lack of documentation on the Edison is getting a bit ridiculous since the os hasn't been updated in a year.
We understand that the documentation can be limited in some aspects and having that kind of documentation would be useful. I'll make sure to pass your feedback to the proper team so they can consider it and improve current documentation. Regarding the image updates, we would like to let you know that some months ago was released a new Edison image with a patch, please take a look at https://software.intel.com/iot/hardware/edison/downloads Intel® Edison Module Downloads.
Moreover, regarding disabling services, it was just an idea that we believed may help you to reach what you need, however, depending on the services you disable the system can become unstable, as you have mentioned.
We have been looking for more information that might help you to increase power saving, and we found this site: https://www.scivision.co/measured-power-consumption-of-intel-edison/ Measured power consumption of Intel Edison, there you will find measures of the power consumption using different Edison's image versions, according to that, using the release 2.1 (http://downloadmirror.intel.com/25028/eng/edison-image-ww25.5-15.zip http://downloadmirror.intel.com/25028/eng/edison-image-ww25.5-15.zip) the power consumption is lower than the other ones, so you may use it, however, keep in mind that it will not have all the updates that the other images have. Please consider that those results are not validated by us, however I found them interesting and they might be useful for you.
Additionally, you may also look at https://theiotlearninginitiative.gitbooks.io/embedded-linux/documentation/Power.html Embedded Linux - Power. There you will find instructions to decrease the power consumption and also useful links about this topic. I haven't tested these options, but I wanted to share them with you.
Another option would be to build a new image with the necessary changes like removing packages that you won't need and see if you can reach the desired power consumption level. However, image customizations are beyond of our support scope. If you would like to explore this option, I recommend you to start by checking the Yocto documentation which is available here: http://www.yoctoproject.org/docs/current/yocto-project-qs/yocto-project-qs.html Yocto Project Quick Start and the Edison building process which is described here: https://software.intel.com/en-us/node/593591 Build an Intel® Edison Board Image Using Bitbake.
Hope you find this information helpful.