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Chapter 2: Device Information & Diagnostics

Once your Android device is connected, DroidMind, through your AI assistant, can provide a wealth of information about the device and help diagnose issues. This chapter covers retrieving properties, capturing visuals, and diving into various logs and diagnostic reports.

Remember to replace emulator-5554 or your_device_serial with the actual serial of your target device in the example queries.

2.1 Retrieving Device Properties

You can ask your AI assistant to fetch detailed properties of a connected device. This includes information like the device model, brand, Android version, SDK level, build number, and much more.

How to ask your AI assistant:

"Tell me about the device emulator-5554." "What are the properties of your_device_serial?" "Get device info for emulator-5554."

Expected DroidMind Action:

DroidMind will use the device_properties tool.

Example Response from AI:

# Device Properties for emulator-5554

**Model**: sdk_gphone64_x86_64
**Brand**: google
**Android Version**: 12
**SDK Level**: 31
**Build Number**: SE1A.220601.001

## All Properties

```properties
[ro.product.model]: [sdk_gphone64_x86_64]
[ro.product.brand]: [google]
[ro.build.version.release]: [12]
[ro.build.version.sdk]: [31]
[ro.build.display.id]: [SE1A.220601.001]
[ro.product.manufacturer]: [Google]
[persist.sys.timezone]: [America/Los_Angeles]
...
(many more properties)

This information is invaluable for understanding the device's hardware and software configuration, which is often crucial for debugging.

2.2 Capturing Screenshots

A picture is worth a thousand words, especially in UI debugging. DroidMind can capture a screenshot of the device's current display.

How to ask your AI assistant:

"Take a screenshot of emulator-5554." "Capture the current screen of your_device_serial." "Show me what's on the screen of emulator-5554."

Expected DroidMind Action:

DroidMind will use the screenshot tool. The AI assistant will then typically display the image.

Example Response from AI:

Okay, here is the screenshot from emulator-5554:

[Image data would be displayed here by the AI assistant]

I've captured the screen. The image shows the device's home screen with several app icons.

Screenshots are returned as JPEG images by default to save space, with a quality setting of 75. You can specify quality if needed, though most users won't need to.

2.3 Working with Logcat (Device Logs)

Logcat is Android's logging system, providing a stream of messages from the system and applications. DroidMind allows you to fetch these logs.

2.3.1 General Device Logcat

Retrieve recent general logs from various buffers on the device.

How to ask your AI assistant:

"Show me the last 500 logcat lines from emulator-5554." "Get the device logs for your_device_serial, focusing on the 'crash' buffer." "Fetch logcat from emulator-5554 with the filter 'ActivityManager:I *:S' for the last 200 lines."

Expected DroidMind Action:

DroidMind will use the device_logcat tool. You can specify:

  • lines: Number of recent lines (default: 1000).
  • filter_expr: ADB logcat filter expression (e.g., "MyAppTag:V *:S").
  • buffer: Log buffer (e.g., main, system, crash, radio, events; default: main).
  • format_type: Log output format (e.g., threadtime, brief; default: threadtime).
  • max_size: Max characters for the output (default: 100KB).

Example Response from AI:

# Device Logcat Output 📱

## Last 500 Lines from 'main' Buffer

```log
01-15 10:30:01.123  1234  5678 I ActivityManager: Displayed com.example.app/.MainActivity: +100ms
01-15 10:30:01.456  8765  4321 D MyAppTag: User clicked the login button
...

### 2.3.2 App-Specific Logs

Filter logcat output for a specific application package.

**How to ask your AI assistant:**

> "Get logs for the app `com.example.myapp` on `emulator-5554`."
> "Show me the last 200 log entries for `com.example.anotherapp` on `your_device_serial`."

**Expected DroidMind Action:**

DroidMind will use the `app_logs` tool.
*   `package`: The package name of the app.
*   `lines`: Number of recent lines to fetch (default: 1000).

**Example Response from AI:**

Logs for App 'com.example.myapp' 📱

Recent Log Entries

01-15 10:32:05.678  8765  4321 D com.example.myapp: Login successful for user 'bliss'
01-15 10:32:05.999  8765  4322 I com.example.myapp.NetworkService: Data sync initiated.
...

If no logs are found, it might mean the app isn't running or isn't generating logs with that package name identifier.

## 2.4 Understanding ANR & Crash Logs

When an app freezes or crashes, Android generates specific diagnostic logs.

### 2.4.1 Application Not Responding (ANR) Traces

ANRs occur when the UI thread is blocked for too long.

**How to ask your AI assistant:**

> "Are there any ANR traces on `emulator-5554`?"
> "Show me the latest ANR logs from `your_device_serial`."

**Expected DroidMind Action:**

DroidMind will use the `device_anr_logs` tool.

**Example Response from AI:**

Application Not Responding (ANR) Traces

ANR Trace #1: anr_2023-01-15-10-35-00-123.txt

File Info: -rw-rw---- 1 system system 123456 2023-01-15 10:35 /data/anr/anr_2023-01-15-10-35-00-123.txt

----- pid 8765 at 2023-01-15 10:35:00 -----
Cmd line: com.example.myapp

DALVIK THREADS (15):
"main" prio=5 tid=1 Blocked
  | group="main" sCount=1 dsCount=0 flags=1 obj=0x12c08a00 self=0xb4800200
  | sysTid=8765 nice=0 cgrp=top-app sched=0/0 handle=0xb73ff4f4
  | state=S schedstat=( 0 0 0 ) utm=93 stm=42 core=0 HZ=100
  | stack=0xbe227000-0xbe229000 stackSize=8MB
  | held mutexes= "mutator lock"(shared held)
  at com.example.myapp.HeavyComputation.perform(HeavyComputation.java:25)
  - waiting to lock <0x09a8f2c8> (a java.lang.Object) held by thread tid=10
...

I found one recent ANR trace for com.example.myapp. It seems the main thread was blocked waiting for a lock.

### 2.4.2 Application Crash Logs

These logs provide information about app crashes, including tombstones (native crashes) and Java crash reports.

**How to ask your AI assistant:**

> "Check for any application crash logs on `emulator-5554`."
> "Show me the latest crash reports from `your_device_serial`."

**Expected DroidMind Action:**

DroidMind will use the `device_crash_logs` tool.

**Example Response from AI:**

Android Application Crash Reports

System Tombstones

Recent system crash tombstones:

Tombstone #1: tombstone_00

*** *** *** *** *** *** *** *** *** *** *** *** *** *** *** ***
Build fingerprint: 'google/sdk_gphone64_x86_64/generic_x86_64:12/SE1A.220601.001/8804948:userdebug/dev-keys'
Revision: '0'
ABI: 'x86_64'
pid: 9012, tid: 9034, name: Thread-2  >>> com.example.crasher <<<
...

Dropbox Crash Reports

No crash reports found in dropbox.

Recent Crashes in Logcat

01-15 10:40:15.123  9012  9034 E AndroidRuntime: FATAL EXCEPTION: Thread-2
01-15 10:40:15.123  9012  9034 E AndroidRuntime: Process: com.example.crasher, PID: 9012
01-15 10:40:15.123  9012  9034 E AndroidRuntime: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String java.lang.Object.toString()' on a null object reference
...

I found a tombstone and a recent Java crash in logcat for com.example.crasher.

## 2.5 Analyzing Battery Statistics

Understand how power is being consumed on the device.

**How to ask your AI assistant:**

> "Analyze the battery usage on `emulator-5554`."
> "Show me the battery stats for `your_device_serial`."

**Expected DroidMind Action:**

DroidMind will use the `device_battery_stats` tool.

**Example Response from AI:**

Battery Statistics Report 🔋

Current Battery Status

Current Battery Service state:
  AC powered: false
  USB powered: true
  Wireless powered: false
  Max charging current: 0
  Max charging voltage: 0
  Charge counter: 0
  status: 2
  health: 2
  present: true
  level: 75
  scale: 100
  voltage: 4200
  temperature: 250
  technology: Li-ion

Key Metrics

  • Battery Level: 75%
  • Temperature: 25.0°C
  • Health: Good

Battery History and Usage

... (Details on discharge history and power consumption)

This can help identify apps or processes that are draining the battery.

## 2.6 Generating Bug Reports

A bug report is a comprehensive archive of diagnostic information, including system logs, device state, running processes, and more. It's very useful for in-depth debugging.

**How to ask your AI assistant:**

> "Generate a bug report for `emulator-5554`."
> "Capture a bug report from `your_device_serial` and include screenshots."
> "Create a bug report for `emulator-5554`, save it to `/tmp/my_bug_report.zip`."

**Expected DroidMind Action:**

DroidMind will use the `capture_bugreport` tool.
*   `output_path` (optional): Local path on the DroidMind server machine to save the bug report ZIP file. If empty, a summary is returned and the file is saved to a temporary location.
*   `include_screenshots` (optional, default `True`): Whether to include screenshots.
*   `timeout_seconds` (optional, default `300`): How long to wait for the bug report.

**Example Response from AI (if `output_path` is provided):**

Okay, I'm capturing the bug report from emulator-5554. This might take a few minutes... ... Bug report saved to: /tmp/my_bug_report.zip (15.23 MB)

**Example Response from AI (if `output_path` is NOT provided):**

Okay, I'm capturing the bug report... ...

Bug Report for emulator-5554

Temporary file saved to: /tmp/droidmind_bugreport_XXXXXX/bugreport_emulator-5554.zip (15.23 MB)

Bug Report Contents

  Length      Date    Time    Name
---------  ---------- -----   ----
  1234567  01-15-2023 10:50   bugreport-emulator-5554-2023-01-15-10-50-00.txt
    56789  01-15-2023 10:50   screenshot.png
...

To extract specific information from this bug report, you can use:

  • unzip -o /tmp/droidmind_bugreport_XXXXXX/bugreport_emulator-5554.zip -d <extract_dir> to extract all files
  • unzip -o /tmp/droidmind_bugreport_XXXXXX/bugreport_emulator-5554.zip bugreport-*.txt -d <extract_dir> to extract just the main report

Note: This is a temporary file that may be cleaned up by the system later.

Bug reports are large and complex. Your AI assistant might be able to help you analyze specific parts of it if you extract them.

## 2.7 Dumping Heap for Memory Analysis

Heap dumps are snapshots of an app's memory, useful for diagnosing memory leaks and understanding object allocation.

**How to ask your AI assistant:**

> "Dump the Java heap for the app `com.example.memoryhog` on `emulator-5554`."
> "Capture a native heap dump for process ID `12345` on `your_device_serial` and save it to `/tmp/native_heap.hprof`."

**Expected DroidMind Action:**

DroidMind will use the `dump_heap` tool.
*   `package_or_pid`: The app package name or its Process ID (PID).
*   `output_path` (optional): Local path on the DroidMind server machine to save the heap dump file. If empty, a default temporary location is used.
*   `native` (optional, default `False`): Whether to capture a native heap dump (C/C++) instead of a Java heap dump. Native dumps often require root.
*   `timeout_seconds` (optional, default `120`): How long to wait.

**Example Response from AI (for Java heap dump):**

Capturing Java heap dump for process com.example.memoryhog... ... Java heap dump saved to: /tmp/droidmind_heapdump_XXXXXX/com.example.memoryhog_java_heap_20230115_110530.hprof (5.75 MB)

To analyze this Java heap dump:

  1. Convert the file using: hprof-conv /tmp/droidmind_heapdump_XXXXXX/com.example.memoryhog_java_heap_20230115_110530.hprof converted.hprof
  2. Open in Android Studio's Memory Profiler
  3. Or use Eclipse Memory Analyzer (MAT) after conversion
Heap dump analysis is a specialized task. The AI can guide you on how to use tools like Android Studio's Profiler or MAT to analyze the `.hprof` file.

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Next, we'll learn how to manage files and directories on your devices in **[Chapter 3: File System Operations](./file_system.md)**.