Reduce idle power consumption of a iMX7D based board

[michiel_tjampen]

I'm working on a data logger using a IMX7D som (toradex) as central processing and I'm trying to reduce the idle power consumption as much as possible. Attached is my current dts.

The idle is at 680mW without ethernet cable attached and 900mW with, the phy on the SoM has a bug so i can't turn it off in user space.

The only things i'm using:

• sd card
• all serial ports
• spi3
• i2c3
• ethernet

I've read that you can reduce the ethernet to 10Mbit but haven't figured out how. 

I also read it's possible to add a lower frequency point for the cores but that it doesn't help much.

Currently using kernel 5.4.129 (compiled with defaults according to toradex but with support for the max14830.

Any suggestions?

[michiel_tjampen]

Hi igor,

So i should see much lower idle consumption and try to mimic the settings on page 17, no idea how though. I'll also check with a heatcam what is using the most power if it isn't the core.

Regarding contacting Toradex, i asked on their forum first and got the suggestion to ask NXP directly. But maybe that meant the link you gave instead of the forum.

[igorpadykov]

Hi Michiel

for reducing power consumption one can look at sect.5. Reducing Power Consumption

AN5383  i.MX 7DS Power Consumption Measurement

For software implementation may be recommended to apply to  https://contact.nxp.com/new-prof-svcs-sw-tech  or toradex tech support (note  toradex IMX7D som  and  kernel 5.4.129 are not supported by nxp).

Best regards
igor