Android Apk

The program

Android application is a hybrid ionic framework app. It uses the following plugins and JS libraies:

Modified (added a function) to send not encoded packets. Modified to a) make pictures seen in "Pictures" immideately, and b) add proper rotation of the image. Modified to rotate to absolute angles, not increments.

The "android" part of an ionic project can be downloaded from the "download" section. The apk can be build with Android Studio, "import"-build.cradle; the project does not require anything else to build (no need to install plugins, libraries or frameworks).

Status bar

Apk turns BLE automatically. If not, please check permissions of the app on the smartphone.

The status bar shows connection status. a) If there is nothing displayed on the status bar, the application does not see any BLE packets from the device (the device is off). 2) Battery level and status should be seen immediately after the device is on. 3) Click "CONNECT" menu item to connect. When connected (usually takes 1-10 s) BLE icon appears at right.


Menu list depends on the mode. For example, if the device is just turned on, only "CONNECT", "FILE", "EXIT APP" are available.


Disconnect the device. The device is still advertising.


Turns the device off completely. The same to long push button. After that the device can be awaken only with button push (short push - advertising, long - dfu, see "the device" page)


Application can run in the background. If forgotten it may drain battery of a smartphone. If application is terminated from the background by android's swipe- out way, BLE is still running. The best way to terminate the application is "EXIT APP" menu item, it both suspends application from running in the background and switches BLE off. "EXIT APP" does nothing to the device. Smartphone's hardware "back" button is programmed to perform the same action as "EXIT APP" menu item.


To "zoom" swipe the area from left to right. To "pan" use cross icon at top right of the graph. To reset click "reload" icon at the right-top of the graph. To see value labels click to the line or column on the graph.


At zero angles 3D model is shown from some predefined viewpoint. The zero-angles view can be adjusted by swiping the screen left-right, top-bottom (in the "stop" mode).

To reset to default view click pitch or roll angles.

If there are multiple data loaded with "read record" or "file load" the data can be navigated with "next-right", "next-left" buttons or played (consequence click to "play" will call frames with 1s, 0.5s, 0.2s, 0.1s intervals (x1,x2,x4,x8), to stop click "next-left" or "next-right" button);



How fast the device sends data

Graph and model drawing performance depends on a smartphone. If a smartphone gets unresponsive, increase stream period, and/or increase graph/model update periods
Were to save/load files. "File" menu


Full range, resolution is 10 bits from -range to +range, e.g. at 2g resolution is 4mg/digit


1 step is ~4x resolution of the accelerometer, e.g. at 2g of full scale 1 step is 16mg

time interval after which angles are calculated and reported (see "the device" page for the diagram)

Select combination of axes and logic to generate trigger event

At what frequency accelerometer does sampling (both "live" and "offline") and at what frequency FIFO is filled ("offline" modes). Higher frequency means more accurate response. (higher is better). On the other hand, higher frequency means also more current consumption by the accelerometer: 10Hz: 4uA, 50Hz: 11uA, 100Hz: 20uA, 200Hz: 40uA. Total battery drain is this current +MCU activity (calculation etc.) current+BLE current.


Disallows (unchecked) alarms and photos in "record" mode regardless of "play sound" and "take photo" settings. Allows if "play sound" and/or "take photo" are set (AND logic to them).

Play alarm sound on trigger conditions. Select sounds from the dropdown list

How long the alarm is played.

How much time should pass until next alarm/photo will be allowed. To filter frequent alarms/photos.

Enabler, back or front camera, folder to save photos

Another filter to pictures. Maximal number of photos allowed. Now# shows current number of pictures taken since the program start. If new max. number is entered, current number resets to zero.

There are two categories of the settings. Device related (stream period, accelerometr and trigger settings etc) and apk related (folders, alarm on/off alarm/photos settings, etc.). Device related setting require the "connection" state. If the device is disconnected, warning dialog will be shown and the settings in the app's fields will be restored. Nontheless apk related settings will be applied regardless of connection state and warning dialog. This is done to have a chance to change alarms without interference with the "offline" modes of the device. Note "atRecord" checkbox belongs to device's setiings, since it is used by the firmware. In any case aftr "APPLY" button click the apk shows actual data on the screen.