I am looking to take control of the power/battery switching on a laptop. My goal is to be able to switch between the two when I choose. Is there a specific BIOS command I need to know about? Can anyone help me?
I am looking to create a program that allows me to decide when my laptop should be on battery power and when it should be on AC power without having to unplug it.
Related
I have a raspberry pi 3.
Whenever I want to shutdown, I always execute this command:
sudo shutdown -h now
And I will wait until only the red light is lighting. (And I always remove the power until only the red light is lighting)
But the problem is : every time I shutdown, I can't boot it again. I need to install the OS into the SD card again every time after I shutdown.
If anyone has the same problem ? Please help me. Thanks a lot.
I encountered this after my comment. As I mentioned, I perform the same steps to safely shutdown, unplug, and store.
Based on this page, you might be getting a corrupt SD card. Not sure if any of these apply.
https://www.raspberrypi.org/documentation/installation/sd-cards.md
If you are having trouble with corruption of your SD cards, make sure you follow these steps:
Make sure you are using a genuine SD card. There are many cheap SD cards available which are actually smaller than advertised or which will not last very long.
Make sure you are using a good quality power supply. You can check your power supply by measuring the voltage between TP1 and TP2 on the Raspberry Pi; if this drops below 4.75V when doing complex tasks then it is most likely unsuitable.
Make sure you are using a good quality USB cable for the power supply. When using a high quality power supply, the TP1->TP2 voltage can drop below 4.75V. This is generally due to the resistance of the wires in the USB power cable; to save money, USB cables have as little copper in them as possible, and as much as 1V (or 1W) can be lost over the length of the cable.
Make sure you are shutting your Raspberry Pi down properly before powering it off. Type sudo halt and wait for the Pi to signal it is ready to be powered off by flashing the activity LED.
Finally, corruption has been observed if you are overclocking the Pi. This problem has been fixed previously, although the workaround used may mean that it can still happen. If after checking the steps above you are still having problems with corruption, please let us know.
Hope that helps.
Cheers.
Ian
Since we are still struggling with sending and receiving bluetooth data, we want to try a different way, ignoring bluetooth for now.
Is it possible to write a software, which Windows or Linux is recognizing as a Hardware Gamepad for simulating (so we only need to change the input of that tool to bluetooth input later)?
And if it is possible, what do I need to know for achieving that? Thank you!
(We are using C/C++)
So various people around my house have been stealing my mouse and I was wondering if I could store a program on the mouse which runs whenever it's plugged in, asking you for a password. I know you can run a program stored on a computer when a device is inserted into a USB slot but that means I can't stop people using my mouse if the specific laptop he's using hasn't got the program installed.
Also, if this was possible, what language would use? I would like it to work on windows, linux and OSX to cover all bases.
Thanks for any help!
I am looking into what's the best method for getting external data (custom built hardware) and to intercept and process this data (programming language / tool), the cheapest and easiest and with the least learning curve.
Background:
I am a web dev.
External device will be switches, motion detection, velocity detection
Programming language: Delphy (which I don't know)? or C# (which I know for web dev) or other?
Anyone done anything like this before? Got any advice?
Any and all information is appreciated.
D
The easiest solution might be to use an Arduino.
It's :
cheap (~ 30$)
easy to program
easy to connect to your PC (it use an USB cable which emulate a serial connection)
have a HUGE community with tons of tutorials for doing whatever you want
Here is an example how to control a led using C#
We are in the process of developing an method of caching so that our app can continue to operate in an area with very little/no signal.
Obviously users will try to continue to use functions that require data and we need to handle the inevitable failure of these requests appropriately.
Essentially we are sat in the office, switching airplane mode on and off to simulate entering/exiting signal then adjusting our app to fix any issues this may arise.
What I'd like to know is, is using airplane mode going to give us a reasonable simulation of entering/exiting an area with no data or are there other implications?
I've seen questions raising the issue that the 3G/EDGE connection may not always wake up after airplane mode is switched on - while I appreciate this method is no way as good as actually being out in the field testing, if we can get a reasonable simulation and account for the majority of the problems that arise then I think this is an acceptable tradeoff.
I apologise if this has been asked before, I did do a search on here & on google but couldn't find any appropriate results.
You should try the Network Link Conditioner
There is a WWDC 2012 session called Networking Best Practices that mentions it (but he does not explain how to use it there).
To get it, you have to go to XCode/Open Developer Tool/More Developer Tools.. and download the latest Hardware IO Tools for XCode.
Once you install it from the IO Tools pkg, "Network Link Conditioner" will appear in System Preferences
You can then do something like 100% packet loss to simulate one of those routers that pretends you are connected but actually doesn't work.
On iOS, the network link conditioner is under Settings / Developer (you must have enabled Developer mode in XCode first to see it)
The main problem is that in the Airplane Mode the networking operations fail fast, while spotty mobile signal will lead to timeouts and a-few-bytes-an-hour speeds. This is usually a significant difference from the UI viewpoint. (It might be worth a try to use some bandwidth throttle to starve the testing machine and see how it behaves when the network starts to break?)
A few years back, when testing remote devices which used the cell network to communicate with the 'home base', we did things like move them into a shielded room (make shift), place large shields on three of four sides to force them to connect to a certain tower (and therefore, network), etc. Brute force physical methods. Since this actually cuts off the signal, it may be a more realistic approach.
You may also want to try this through your wlan-router. First, disable data roaming on your iPhone. Then, let the iPhone be connected to the internet through your wlan network. Then, disconnect the gateway on your wlan router while your iPhone is still connected to the wlan network.
This depends on what failure modes you are trying to test.
I use Airplane mode as a first pass check to make sure an app submission isn't quickly rejected.
Other network failure handling checks might include:
3G only (no wifi).
WIFI only (in Airplane mode).
Pulling the power cord on the WIFI access point.
Pulling the network cable from the back of the WIFI access point after connecting to it (Reachability may falsely say yes).
Walking in and out of a basement
elevator (or other Faraday cage) in the middle of a transfer.
Driving between 2 cell towers during a data transfer.
Walking between 2 enabled WIFI access points between connection and data transfer.
Starting the app after more than 30 minutes of device inactivity (radios may be idle).
Running the app while another app (Safari, Mail) is downloading in the background.
etc.