test result of battery current against display brightness and GPS power mode

mqy meng.qingyou at gmail.com
Sat Mar 28 18:56:12 CET 2009


Thanks a lot!

With "echo > /sys/bus/spi/devices/spi2.0/state sleep", the current drops 
from 82.125 mA to 81.562 mA within 10 minutes. The battery is fully charged before test.

My kernel:
# uname -a
Linux om-gta02 2.6.28-rc4 #1 PREEMPT Sun Feb 8 19:53:16 CET 2009 armv4tl unknown

Before read your reply, I get nothing by removing SD card, ifdown usb0, power off backlight.

Here is the new script I used:


# for exit SSH shell, unplug USB
sleep 5 

# strange, 1 to power of backlight
echo > /sys/class/backlight/gta02-bl/bl_power 1

echo > /sys/bus/spi/devices/spi2.0/state sleep

for ((i=0; i<20; i++)); do
  echo "i = $i:"
  cat /sys/class/power_supply/battery/{current_now,capacity,voltage_now}
  sleep 30 

echo > /sys/class/backlight/gta02-bl/bl_power 0
echo > /sys/bus/spi/devices/spi2.0/state normal

But comparing to your ~50 mA, 82 mA is still too large :)

Could anybody who has latest SHR installation on GTA02, give a test to verify?

Before start this script, please make sure:
1. `/sys/bus/platform/devices/neo1973-pm-gps.0/pwron` output 0, else you can echo 0 into it.
2. disable GSM/WIFI/Bluetooth in SHR settings
3. SSH to FR through USB if you haven't connect to it.
4. stop /etc/init.d/xserver-nodm, /etc/init.d/frameworkd
5. killall batget; killall wakerd;
6. start the above script, e.g. `power.sh > output_power.txt &` , exit SSH shell, unplug USB

10 minutes later, you can plug USB and SSH into FR again. If you can't wait for 10 minutes, 
modify "sleep 30" to "sleep 5" or something else.

I'd like to say "thank you" to Rask Ingemann Lambertsen again :)

On Fri, Mar 27, 2009 at 05:21:59AM +0800, Qingyou Meng wrote:

> To set brightness: write (brightness_percent / 100 * 255) to file
> "/sys/class/backlight/gta02-bl/brightness"

   I think that's why you get so high currents. This

# echo >/sys/class/backlight/gta02-bl/brightness 0

doesn't do what you hope it does. You should try

# echo >/sys/class/i2c-adapter/i2c-0/0-0073/pcf50633-regltr.9/glamo3362.0/glamo-spi-gpio.0/spi2.0/state sleep

also. A shorthand for that file is /sys/bus/spi/devices/spi2.0/state. When
the display isn't blanked, it reads 'normal'.

   But, IMHO, consider using a higher-level interface (such as
freesmartphone.org) to turn off the display instead of trying to find all
the places to mess with under /sys yourself.

Rask Ingemann Lambertsen
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