This time I tackled the wasteful touch sensor: http://downloads.qi-hardware.com/people/werner/anelok/tmp/current-reduction-2.png
"display off in ui_off" is where we left off the last time, with an average standby current of about 6.7 mA. "use msleep also in init_cal" eliminates the last bastion of mdelay, the touch sensor calibration. Anelok now takes little naps between samples. So far, so good, but it still busy-waits while the touch sensor controller is sampling. So this was next. This involved a bit of infrastructure work, e.g., teaching the firmware how to handle interrupts (unexpectedly painless), and deepening my understanding of how wakeups from a deep sleep are handled in this processor (that took a while. See fw/plat/sleep.c for details.) "deep-sleep while waiting for TSI" shows the result of all this: the MCU now spends most of its time in deep sleep while in standby. Standby current is down to 0.9 mA, most of which should now be the boost converter. One unexpected side-effect of all this is that the calibration seems to take about twice as long as before. Not sure why. Deep sleep itself should only add about 1 ms to the whole process, but this difference is much longer. To be investigated later. - Werner _______________________________________________ Qi Hardware Discussion List Mail to list (members only): [email protected] Subscribe or Unsubscribe: http://lists.en.qi-hardware.com/mailman/listinfo/discussion
