I have an app which is running on an android device which has no battery. It's just charging all the time and the app is running. But sometimes the device is not charging and logical to that the phone will turn off.
When it's charging again the device should start from itself and boot. The user shouldn't press the power button. That's the requirement.
Is this possible anyway?
Can I achieve this when I root the device?
Has anybody experiences with that case?
in short: No.
ADB is not running when the phone is powered off, and as #langerhans said, wake on alarm is proprietary
You could do a hardware solution where you hijack the battery pins to a power station or modified charger. (make sure you do not feed any power through usb at the same time)
It should be cheap and quite easy to build.
Generally, this is not possible. It is highly device dependant. Some devices allow alarms turning on the phone to ring as an alarm clock even if they are turned off. But this is a proprietary feature and therefore not easily accesible to custom applications.
I have basically the same problem running an Odroid device which luckily turns itself on after power loss, but if I shut it down manually, I can only turn back on with pulling the power.
The only thing I could think off would be an extra watchdog device, but I have no idea if something like that exists. Maybe you'd need to build it yourself.
Related
I want to develop an application that has auto-power on when the device is off.
There is a way to set your device to automatic power on? like a scheduled task?
"I want to develop an application that has auto-power on when the device is off."
Answer: This is impossible. You can't run code on a device which is turned Off.
If it would be possible, every anti-theft App would have something like that to track the phone.
Actually, i want to include a functionality in my android app that when phone is switched off due to low charging, then when i'll connect Power cable or charger to it, then it will booted up or Power on automatically without pressing Power button physically.
Can we make any service keep alive after device switched off ??
is it possible any how?? plz help by sharing your views & exp.
I was searching SO and web but i couldn't find sufficient answer for my particular question. Ok here we go:
Every user can modify screen timeout on android. (when screen turns off when its idle for __ seconds/minutes - users choice ). But user can modify ONLY screen timeout and not when device goes actually to sleep. I found here what happens when device goes to sleep: (Really nice answer by CommonsWare) Android Sleep/Standby Mode
Ok my question is simple. How do i know when my phone will go to sleep? Will it go to sleep immediately after turning screen off? Will it stay "awake" a while after screen was turned off? And most important: Does sleep mode in particular device varies from brand device ( how manufacturer implement this ) or it depends on ROM version (For instance, all ICS powered devices will go to sleep X seconds after screen was turned off )?
You can never really be sure if the device has gone to sleep. At best, I can give you a list of things that would make sure that the device hasn't gone to sleep:
Screen being on - Requires CPU and GPU, and hence RAM, to stay active
Any app holding a wakelock - Even the lowest wakelocks keep the CPU on, though the screen may be switched off
Apart from this, there is no guarantee that the device will go to sleep n seconds after the screen is turned off, even if no wakelocks are being held. This is upto the OEM, and they can alter this.
Keep in mind that Android devices have an option to keep the device unlocked for a certain amount of time after the screen has gone to sleep.
There is small difference in power consumption when you compare a phone with laptops.
Laptops most of the times runs on direct power through charger. (Mostly we carry charge with laptop).
Mobiles mostly run on battery power. (Rarely we carry charger with us).
By keeping this in mind, android has designed in a such a way that, phone will not consume battery power if user is not interacting with the phone. This is to increase battery back up time for user.
That's why when LCD screen power is off (that means user is not interacting with phone), with in fraction of seconds CPU will also go to a mode (sleep mode) where it does minimal work and saves battery power. When CPU is in sleep mode, it accepts commands only from RIL (radio interface layer) which is basically SMS and call functions, and alarms. Other than this CPU will stop executing other applications functions.
Note : If any application wants CPU time for its emergency work when CPU is in sleep mode, then it can request CPU time by using WAKE LOCKS.
For eg : MP3 application has to keep playing songs in its service, even though user has turned off LCD screen. That means MP3 application's service has requested CPU time by using WAKE LOCKS.
Your question : How do i know when my phone will go to sleep?
- Ans : Simple it goes sleep mode when LCD power is off, with in fraction of seconds.
Your question : Does sleep mode in particular device varies from brand device
- Ans : Since android is open source, any OEM can take driver layer , which is GPU license and can modify the power manager drive to behave differently. All these sleep modes and wake locks are finally under control of Power manager driver of Linux kernel layer.
for testing sleep mode/doze in Android 6.0 you should use next commands:
$ adb shell dumpsys battery unplug
$ adb shell dumpsys deviceidle step
more info see here: Optimizing for Doze and App Standby
I have an application that needs to continuously listen for incoming requests over wifi. A service that runs in the background does this job. However, this service falls asleep after a while when the screen turns off.
The solution from what I have searched is to use AlarmManager to keep it awake. But it is said that this will drain the battery of the device.
So, is there another way to do this?
For eg, what do apps like Whatsapp and Skype do? They don't seem to kill too much battery but they have continuously running services right?
Also, in case AlarmManager is the only way, it would be really kind if someone could share a tutorial or example for it.
The solution from what I have searched is to use AlarmManager to keep it awake
That will not help. Once the device falls asleep, your socket connection will be terminated. You would need to use a partial WakeLock plus a WifiLock to keep the device powered on continuously.
But it is said that this will drain the battery of the device.
The WakeLock and WifiLock will definitely drain the battery.
So, is there another way to do this?
Not if you need to use WiFi.
For eg, what do apps like Whatsapp and Skype do?
They do not use WiFi when the device wants to go to sleep. Once the WiFi radio powers down, they use mobile data, so no WifiLock is needed. For mobile data, incoming packets will wake up the device, so you only need a WakeLock while you are actually doing work, rather than constantly.
The best answer is to switch to use C2DM, though.
Actually its not your service which falls to sleep, its your WiFi unit on the device. Manufacturers like HTC (or perhaps all Android devices) have implemented this kind of behavior on their devices in which the WiFi unit goes standby after certain time period of screen-off. This helps the devices to save battery when its not being used.
I'm Developing an Android Application where it's constantly required to keep the App up an running at all time. with the phone connected to a power outlet at all time, Is it possible that if the phone's battery died to Auto-start up the app with no user intervention . *i.e to power up the phone automatically without hitting any power button and start up android since charger is connected. *
then start up my app with android.intent.action.BOOT_COMPLETED and RECEIVE_BOOT_COMPLETED permission
PS: I have tried android.intent.action.ACTION_POWER_CONNECTED but it only works if the phone is already powered up.
I have exactly same requirement as yours.
Can we plan a solution like this:
The Android device is always connected to charger's output.
Charger's power supply is connected to a custom made hardware device which controls power supply to charger.
This hardware device puts charger off until battery is getting low. i.e. 20% remaining.
Once battery is less than 20%, that device automatically switch on the charger.
The "custom made hardware" gets it input from android device itself via USB/WiFi/Bluetooth.
Just a thought. May not be practically possible.
No way doing it if you do not root your device and add reboot scripts to the programs running to show battery charging pictures when device is turned off and charging.for Samsung s2 here is an answer
Maybe you can make an additional app that waits for the BOOT_COMPLETED with its BroadcastReceiver and then check wether the power is connected and start as a new Intent your application?
Just a quick thought..
I have the same problem.
The solution that i will to implement:
1.- get out two(here is my doubt, ¿what two wires?, because i see three, i will use my multimeter for see continuity between wires when i push the button) wires from the power button phone.(when you push that button, it just connect two poles like a switch).
2.- When you have the two wires, so, we build a little circuit with a timer like a 555(integrated circuit). The purpose of the circuit will connect the two wires(from power button phone) by a 5 seconds period every 15minutes.
Obviously this circuit will be running always.