August 26, 2015

Sound Meter (v1.6) manual

Hello. I'm chief developer of Smart tools co.,

This app is a tool to measure sound (noise) level around you. It is using your built-in microphone. It should be called as a SPL(sound pressure level) meter, that is not related to frequencies like dB(A) and dB(C).

 How to use it ???
  - Just open the app, and read the number.
  - If you want to save the data, get the screenshot. Click the camera icon on the app bar.

※ Introduction video

 Examples of sound pressure
  20dB : Rustling leaves, Ticking watch
  30dB : Quiet whisper at 3 ft, Library
  40dB : Quiet residential area, Park
  50dB : Quiet office, Quiet street
  60dB : Normal conversation at 3 ft
  70dB : Busy traffic, phone ringtone
  80dB : Busy street, alarm clock
  90dB : Factory machinery at 3 ft
 100dB : Subway train, Heavy snoring(2ft)
 110dB : Rock music, Screaming child
 120dB : Threshold of pain, Thunderclap
 130dB : Jet engine at 100 ft
 180dB : Space shuttle lift-off

① Menu
② Screen capture

③ Refresh : 3 red lines mean max, mean and min. To reset them, long-click on the center of meter or click the refresh icon.
④ Text / Chart toggle

⑤ Black / White toggle : make your screen dim for saving battery.
⑥ Play / Pause toggle


 Don't blame the app for Maximum Limitation
Most microphones are aligned to human voice (300-3400Hz, 40-60dB). It is enough for voice calls. But it occurs an issue of 16 bits microphone limitation.

See sound pressure at calibrate menu. It'll stop at 32767 (32767=2^15-1). Briefly, 16 bits microphones cannot measure above 96 dB. (more link)

Because of additional optimization (background noise reduction), some devices can measure at most 80 dB. Galaxy S3-S5(81-84db), HTC Desire HD(85db), Galaxy Note(81/91db). Some Motorola and Amazon Fire devices can measure 96 dB fully.

Last year, a german user suggested a trick in order to bypass hardware limitation. Add +30dB at calibrate menu, and close your microphone hole with your finger, so that you can measure a sound over 100dB. Try it out. :)

 How to calibrate it ???
Since 2010, I had calibrated 500+ android devices (Galaxy, LG, Xperia, Motorola and Nexus). It's a pity that the results were changed easily depending on OS version.

In order to calibrate the app correctly, you must compare it with an ACTUAL sound level meter. Otherwise, ensure that the value is 30-35dB in a very quiet room. If the result were out of range, you could add/reduce the number with calibrate menu.

It is an auxiliary tool for reference. Just enjoy it.

Q. It says "Unable to open microphone.".
A. The other app occupies your microphone. Restart your device.

Q. Where is the screenshot stored ?
A. /storage/sdcard0/smart-tools/, /mnt/sdcard/smart-tools/, /storage/emulated/0/smart-tools/... Surely, you can find the screenshots in your Gallery.

Q. I could hear nothing. But it points out 30-40dB.
A. The microphones can catch very low-frequency noise. 0 dB means vaccum (no air).

Q. Is the result dBA weighted?
A. The app had been calibrated by a actual SPL meter with dBA. It can measure "sound pressure level", not related to frequencies.

Q. How to save the data?
A. Get the pro version. It can save charts and export CSV file for MS-Excel.

 Pro version added features
 1) Vibrometer is included
 2) Statistic menu
 3) Level notification
 4) Line-chart duration
 5) No ads
  Get it on Google Play

 What's new?
- v1.6.3 : Material design
- v1.6.2 : Galaxy S6 support
- v1.6.1 : Sound effect On/Off
- v1.6.0 : B/W and reset button
- v1.5 : Action Bar added
- v1.4 : Tablets support
- v1.3 : Line-chart added
- v1.2 : App2SD
- v1.1 : Mean value line
- v1.0 : Sound Meter released (Nov, 2010)

If you have any idea to improve it, feel free to contact me.
Thank you.

August 24, 2015

Gifts from Amazon appstore

The amazon appstore team sent me gifts. Firephone and Fire HD6 tablet.
From now my apps can support Fire devices fully. Thanks Amazon. :)

August 6, 2015

Smart Tools (v1.8) - pending...

Hi. I'm trying to support Material design to version 1.8.

It takes more time than I expected due to compatibility and theme issues.
Please wait for 1 month.

July 15, 2015

Metal Detector (v1.4) manual

Hello. I'm Android Boy.

This app is a tool to measure Magnetic Field Levels using a magnetic sensor (magnetometer). Many users are using it to find electrical wires and stud in the wall. First, watch a demonstration video of my user.

Magnetic field level in nature is about 49μT (490mG). When any metal is near, the value will be increased. If this app does not work as you extect, I recommend to initialize the sensor.

 How to use it ???
  - There is no special usage. Just open the app, and move it around. The number will be changed. That's it.
  - Magnetic sensor will respond to electronic products (TV, PC) due to electromagnetic waves.

※ Introduction video

 Color grades of chart
① Green : Magnetic field level in nature within tolerance.

② Blue : Too low. The sensor might be weakened because of phone heating and age. You should cool down your phone. Otherwise, replace the battery with new one.

③ Red : Too high. There is a metal object nearby. If the value is very high (+170μT), a vibration occurs. To stop it, click a stop icon. You can turn on alarm sound at the settings.

 If it does not work properly...
  - Several devices have no magnetic sensor. Please verify your specifications.
  - A leather case with a magnetic "snap" can make the sensor out of order.
  - Rebooting or Factory reset will be helpful for initializing it.
  - If not solved, visit a customer center of your phone (Samsung, LG, Sony...)

※ Settings
 - Alart level : Select the threshold value of alarm.
 - Beep sound : choose from 4 different sound types.

Q. This app does not work. Number is zero (0).
A. 1500+ devices had no magnetic sensor (Micromax, Karbone ...). Please check your specifications.

Q. Can it find a hidden camera and ghost?
A. If they generate magnetic(electric) fields, this app can catch them. A lot of ghost hunters had downloaded this app, and they had experimented as a ghost detector.

Q. Can it find gold?
A. It is not easy to detect gold. Pure gold is classified as non-ferrous that has no magnetic field.

Q. How far is the effective range?
A. It depends on the performance of your sensor exactly. Anyway, its effective distance is at most 7-8 inches (15-20cm).

 Pro version added features
 1) Compass full version integrated
 2) No ads
  Get it on Google Play

 What's new?
  - v1.4.0 : Minor bug fix, drawer update
  - v1.4 : Material design
  - v1.3 : Actionbar added
  - v1.2 : Tablets support
  - v1.1 : Alarm sound added
  - v1.0 : Metal detector released (Aug, 2011)

If you have any idea to improve it, feel free to contact me.
Thank you.

July 2, 2015

Smart Level (v1.0) manual

Hello. I'm android boy, a chief of developing team of Smart Tools co.,

For 4 years, I had no reason to develop a spirit level because I released a protractor. Recently I found that most users would not select/download my protractor instead of a surface level. :-)

Unlike the paid version, it supports both portrait mode (for phone) and landscape mode (for tablet PC). It has the material theme. In the near future, I'll translate into more languages. Please wait for next update.

※ Introduction video

※ Main features
 1) Surface level
 2) Vertical spirit level
 3) Horizontal spirit level
 4) Zero calibration

※ Tile units
 ① Degree(˚)
 ② Percent(%)
 ③ Radian(rad)
 ④ Roof pitch : for US carpenters, 5½/12"

※ Menu & Settings
 - Text size, Text Color, Background color,
 - Show calibration, Tilt Units, Orientation sensor

※ Lock screen
Touch anywhere on the screen. "Holding..." text will blink. Later I'll consider to add a Lock button.

※ Orientation sensor ??
Most level apps are using only an acceleration sensor. But this way has restrictions. When the result is bigger than 60 degrees, it becomes inaccurate. In particular, it has a trouble to calculate diagonal tilt.

My level app provides its solution. Orientation sensor! The app calculates tilt by using magnetic sensor and acceleration sensor. The result is more reliable. I recommend that you turn on this option.

Several custom ROM and non-magnetic devices cannot activate orientation sensor. Please check your specifications and turn it off.

※ Pending updates
- More languages support
- Camera view

※ What's new?
- v1.0.1 : Drawer update
- v1.0.0 : Theme update
- v1.0 : Smart Level released (July, 2015)

When you have any idea to improve it, feel free to contact me. Thanks.