HDMI Off Power Saving Reality

[amcdonley]

After reading I could save 25mA by turning off the HDMI interface on my RPi 3B robot, with the command "sudo /usr/bin/tvservice -o", I was expecting to see my robot enjoying an extra 20 minutes of idle playtime.

It would appear to be less than 6 minutes, or perhaps nothing at all when no display is connected:
2019-08-24 11:20|[juicer.py.dock]---- Docking 351 completed at 8.1 v after 6.2 h playtime
2019-08-24 14:24|[juicer.py.undock]---- Dismount 352 at 11.0 v after 3.1 h recharge
2019-08-24 20:34|[juicer.py.dock]---- Docking 352 completed at 8.1 v after 6.2 h playtime
2019-08-24 23:39|[juicer.py.undock]---- Dismount 353 at 11.1 v after 3.1 h recharge
2019-08-25 05:57|[juicer.py.dock]---- Docking 353 completed at 8.1 v after 6.3 h playtime
2019-08-25 07:27|[juicer.py.undock]---- Dismount 354 at 10.1 v after 1.5 h recharge
2019-08-25 10:20|[logMaintenance.py.main]** HDMI turned off to save juice **
2019-08-25 10:46|[juicer.py.dock]---- Docking 354 completed at 8.1 v after 3.3 h playtime
2019-08-25 13:50|[juicer.py.undock]---- Dismount 355 at 11.0 v after 3.1 h recharge
2019-08-25 20:10|[juicer.py.dock]---- Docking 355 completed at 8.1 v after 6.3 h playtime
2019-08-25 23:10|[juicer.py.undock]---- Dismount 356 at 11.1 v after 3.0 h recharge
2019-08-26 05:26|[juicer.py.dock]---- Docking 356 completed at 8.1 v after 6.3 h playtime
2019-08-26 08:27|[juicer.py.undock]---- Dismount 357 at 11.0 v after 3.0 h recharge
2019-08-26 14:47|[juicer.py.dock]---- Docking 357 completed at 8.1 v after 6.3 h playtime

Carl_w_Skirt_Qtr_x.jpg (69.43 KiB) Viewed 768 times

[blimpyway]

those 20 minutes savings expected at 6 hours of "playing" are realistic only if the PI is doing nothing (idle consumption 350mA) and all other consumers (motors, drivers, servo, camera, sensor etc..) are turned off.