https://github.com/kisom/battstat

Battery statistics collection.
https://github.com/kisom/battstat

Last synced: 18 days ago
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Battery statistics collection.

• Host: GitHub
• URL: https://github.com/kisom/battstat
• Owner: kisom
• License: mit
• Created: 2015-05-23T05:47:43.000Z (over 9 years ago)
• Default Branch: master
• Last Pushed: 2015-05-24T19:41:16.000Z (over 9 years ago)
• Last Synced: 2024-10-11T02:47:24.364Z (about 1 month ago)
• Language: C
• Size: 121 KB
• Stars: 0
• Watchers: 3
• Forks: 0
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

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README

        
# battstat

## collect battery statistics

I'd like to collect my own statistics about my XPS 13's battery performance,

and I wanted to write some C code. The result is this program: a daemon that

should regularly write a snapshot of the battery and system state to a file.

It uses a binary format for the log, which is defined as

```

struct snapshot {

	/* The percentage of the battery remaining (between 0 and 100). */

        uint32_t        percentage;

	/* Padding */

        uint32_t        pad;

	/* When was the snapshot taken? */

        uint64_t        when;

	/* See below. */

        struct sysinfo  sys;

};

```

The `struct sysinfo` structure is defined in the `sys/sysinfo.h` header. For

modern Linux kernels:

```

struct sysinfo {

        long uptime;             /* Seconds since boot */

        unsigned long loads[3];  /* 1, 5, and 15 minute load averages */

        unsigned long totalram;  /* Total usable main memory size */

        unsigned long freeram;   /* Available memory size */

        unsigned long sharedram; /* Amount of shared memory */

        unsigned long bufferram; /* Memory used by buffers */

        unsigned long totalswap; /* Total swap space size */

        unsigned long freeswap;  /* swap space still available */

        unsigned short procs;    /* Number of current processes */

        unsigned long totalhigh; /* Total high memory size */

        unsigned long freehigh;  /* Available high memory size */

        unsigned int mem_unit;   /* Memory unit size in bytes */

        char _f[20-2*sizeof(long)-sizeof(int)]; /* Padding to 64 bytes */

};

```

A snapshot record is 128 bytes long.

## Usage

```

Usage: ./battstat [-b battery] [-d] [-f statfile] [-h] [-t delay]

        -b battery      Select the battery name to monitor.

        -d              Don't daemonise; run in the foreground.

        -f statfile     Specify the file to write statistics to.

        -h              Print this help message.

        -t delay        Specify the delay in seconds between updates.

```

## Dependencies

* libacpi (`sudo apt-get install libacpi-dev`)

* libpthreads

This only works on Linux.

## Notes

The ACPI charging state (i.e. charging/discharging) didn't seem to be updating,

so I've marked those 4 bytes as unused. Ideas for things they could be used

for:

* brightness: this may be the largest killer of battery life

* wireless activity: also a major factor in battery life

The charge and state section take up 64 bytes. This section could be

rearranged: as the charge is a percentage, its range is 0-100. This

could be stored in a `uin8_t`; the brightness should also be a `uint8_t`,

which means that 62 bytes would be available for additional data.

The brightness would have to be read from the `/sys` file system, I assume.

## License

`battstat` is released under the MIT license. See the LICENSE file for

details.