Pre-production User Guide

Potential problems

At this stage the SmartAngle firmware and apps are under continuous development so we welcome comments, suggestions and bug reports. In particular we are working on maximising battery life and this can sometimes cause problems.

If you encounter a problem:

  • Double click the "Home" key on your device and swipe the SmartAngle app to close it.
  • Note: a single click on "Home" merely forces an app into the background rather than closing it.
  • Wait for the SmartAngle LED to stop flashing then press the membrane button on SmartAngle and reload the app.
  • If this fails:

    • undo the three 3mm Pozi #1 screws on the back,
    • take the battery out,
    • put the same battery back in again,
    • SmartAngle should then respond when you press the membrane button.

Updates and latest information

Please check the FAQ page for answers to the most commonly asked questions about SmartAngle.



  • SmartAngle provides an extra hand when levelling
  • Measure in one place and read the angle on your smart phone or tablet at a location convenient for you to see.
  • "Measure there, read here" leaves both hands free for adjustment and fixing.
  • There are two rare earth magnets inside the long side of SmartAngle - so it will stick to any steel surface such as the saw blade shown below.

Preparing the battery

  • SmartAngle is shipped with the CR2032 battery mounted inside.
  • A small insulation strip is placed under the battery to prevent it draining during storage.
  • Pull the exposed part of the strip to remove it. Slightly unscrew the three 3mm Pozi #1 screws on the back of SmartAngle if the strip is hard to pull out.
  • The LEDs on the front of SmartAngle will flash three times then the right hand LED will flash about once a second.
  • The right hand LED will time-out after 60 seconds and stop flashing if you do not connect to your phone or tablet.

Getting started

  • The pre-production version of SmartAngle works with Apple iPhone, iPod or iPad (iOS version 8 or later).
  • Ensure that Bluetooth is enabled on your phone or tablet - check the "Settings" menu.
  • Download and install the SmartAngle app using TestFlight. (Click here for details.)
  • Press the button on the top of SmartAngle - one of the LEDs will start to flash.
  • Run the SmartAngle app which will take a few seconds to connect to SmartAngle.
  • Your first task is to calibrate SmartAngle as soon as the message below is displayed.
  • Select "OK" and follow the calibration procedure outlined further in this User Guide.
  • Select "Cancel" to use SmartAngle without calibration - it will use default settings.
  • In normal use, after about 5 seconds, the screen will display the current reading in degrees.

Flashing LEDs, timeouts and the "Home" button

  • When you press the membrane switch on top of SmartAngle both LEDS will flash then the right hand one will flash at a rate of about twice a second.
  • It will stay in this state until you run the app and it connects via Bluetooth.
  • SmartAngle will switch itself off after about 60 seconds if you don't run the app.
  • When you run the app, and it connects to SmartAngle, the LED will flash much slower - about once every two seconds.
  • SmartAngle will switch itself off after about 300 seconds (5 minutes) if you do nothing with the app
  • You can change this "Maximum connection time" in the Options menu. Reducing it will save battery power.
  • When the SmartAngle app is running a single press of the "Home" button will send it to the background and display your home screen.
  • Before it is forced into the background the SmartAngle app will put SmartAngle to sleep (no LEDs flashing) - to save battery power.

Main screen: degrees, percentages, ratios, falls

Each time the app starts it displays a screen with the value shown in degrees.

Tap near the centre of the screen to select the type of display.



Fall in mm/m:

Fall in in/ft:

Locking an orientation

Tap the SmartAngle icon (lower right) to lock the angle relative to the current icon orientation. For example, if the icon is shown with the long side downwards, all subsequent readings will be shown relative to this position. A lock symbol is displayed when the readings are locked. Tap again to release the lock.

The icon normally rotates as SmartAngle rotates - this shows the surface that angles are currently relative to. Locking prevents this automatic rotation so angles are always relative to the current surface. This means that values will go from zero degrees right round to 359.9 degrees.

Setting zero

Tap the "ZERO" button to set the angle to zero. All subsequent readings will be shown relative to this zero angle. Tap again to return to normal operation.

Turning sounds on/off

Tap the speaker symbol (top left) to disable/enable voice messages and stop warnings.

Changing resolution

Tap "0, 0.5, 0.1" to change the resolution of the display.

Holding a value

Tap the "HOLD" button to hold (freeze) the current reading. An additional button, "STORE", will be displayed so you can add the value to the stop table is you wish. Tap "HOLD" again to release the hold.

Viewing stops

Tap the "STOPS" button to access the table of digital stop angles.

Tap any value to set a stop - tap again to clear it. The image below shows a stop set at 22.5 degrees.

Main menu options

Tap the menu (three horizontal lines, top right) to access the main menu options.


Calibration video:

  • Calibration is done in seven steps - rotating SmartAngle between steps.
  • Instructions on the screen tell you what to do for each step.
  • You can cancel calibration at any time by tapping "< Main Menu" (top left).
  • When all seven steps are complete you should tap "Save" to save the new calibration values.

Calibration steps

  • Step 1: SmartAngle facing you, long side down.
  • Step 2: rotated horizontally by 180 degrees - long side down, facing away from you.
  • Step 3: with the long side held against a vertical surface, facing towards you.
  • Step 4: with the long side held against a vertical surface, facing away from you.
  • Step 5: upside down facing you - easily done by holding it under a table top.
  • Step 6: on a short side with the button bottom left.
  • Step 7: on a short side with the button bottom right.


You can select a background colour for app screens.

The slider allows you to select how much gradient (lighter in the centre of the screen, darker towards the edges) is applied to the background colour.

Sounds and other options

Note: you must click on "Save" (top right) to save any changes you make to the options.

  • You can disable/enable the voice messages SmartAngle uses to tell you the angle after the value has stabilised for a few seconds.
  • The "Voice stability time" is the time, in seconds, that SmartAngle will wait for a value to settle before reading it out.
  • You can select the start and stop tones used when SmartAngle approaches any digital stops you have set.

Scroll the screen to see more options.

  • LEDs use power and will shorten battery life when on. By default they do not flash when you approach a stop angle but you can enable them here.
  • The "Maximum connection time" defines how long, in seconds, SmartAngle will stay awake before going to sleep to save power. SmartAngle my be woken up by pressing the membrane switch.
  • The "Show diagnostic messages" function is used during software testing. If selected it will display the raw data from SmartAngle on the main screen

Digital stops

The top of the screen shows the number of stops that have been selected (in brackets).

Standard stops

SmartAngle uses tones to tell you when you are moving towards or away from a stop - a required angle. A number of useful stops are provided by default.

The image above shows a stop selected at 45 degrees so SmartAngle will provide tones from about 35 degrees to 55 degrees with the tone getting higher the closer it gets to 45 degrees. The tone becomes continuous when the stop is reached.

Saved hold points

Stops may also be added directly from the main screen using "HOLD" followed by "STORE" feature.

Scroll the Digital Stops screen to see stops created in this way shown below the standard stops.

Deleting stops

Any stop may be deleted by swiping left on it then selecting "DELETE".

Adding stops

Click the plus ("+") symbol (top right) to add a new stop.

Multiple SmartAngles

  • The SmartAngle app will try to connect to the nearest SmartAngle.
  • If it finds more than one SmartAngle within range it will try to connect to the last one you used.
  • If it finds a SmartAngle different from the one you last used it will ask for permission to use it.
  • After giving permission you will have to press the button on the front of SmartAngle to restart the connection.
  • Note: connection will take a little longer if the SmartAngle is not the same as the last one you used.

Changing the battery

SmartAngle uses a single CR2032 button cell battery.

  • Unscrew the three 3mm x 6mm Pozi #1 countersunk screws on the back of SmartAngle.
  • Separate the lid from the base.
  • Use a finger and thumb to carefully unclip the old battery from the holder. (See note below if it is stiff.)
  • Gently push the new battery into the holder with the positive ("+") side upwards towards you.
  • Replace the lid and refit the three screws.

Stiff battery

The clips that hold the battery in place may be very strong - making it impossible to remove the battery with your fingers.

In this case you can use the end of a screwdriver to flick the battery out of the holder.

Take great care that you don't damage the printed circuit board when you do this - use the screwdriver blade on the side of the battery labelled "Battery CR2032".

When replacing the battery, first put it into the side of the socket opposite the two longest connectors before pushing down on the other side so that it snaps into place.

Questions, comments, suggestions, problems

Check out the SmartAngle Frequently Asked Questions (FAQ) page or contact us if your question is not answered there.

We welcome comments and suggestions that will help us improve SmartAngle. Drop us an email to let us know your thoughts.

Let us know if you find a problem with SmartAngle or a bug in the app. We hate bugs and we will fix them!

Warranty (UK)

In the UK consumer rights are protected by the Consumer Rights Act 2015.

In this warranty:

  • "SmartAngle" used alone means the combination of SmartAngle hardware, its firmware and the SmartAngle software app;
  • "you" means the original purchaser of SmartAngle;
  • "QUS", "we" and "us" mean Quite Useful Stuff.

QUS warrantees that SmartAngle is of satisfactory quality, fit for purpose as defined by us, free of defects, safe to use, reasonably durable and as described in this document, on the QUS web site and in QUS marketing material ("the requirements").

  • For a period up to 30 days after purchase you have the right to return the SmartAngle hardware for a full refund should it not meet the requirements. During this period, if the problem is with the SmartAngle App, we may make one attempt to fix it before you can claim a full refund.
  • For a period up to six months after purchase, if we cannot show that SmartAngle met the requirements at the time of purchase, you have the right to a replacement or repair. If an attempt at repair is not successful, or if we choose not to attempt a repair or to provide a replacement, you have the right to a full refund.
  • Beyond six months after purchase you have to show that SmartAngle did not meet the requirements at the time of purchase before you can claim a repair, replacement or refund (full or partial).

In all cases, the limit of our liability shall be the price paid by you at the time of original purchase and we shall not be liable for any consequential loss suffered by you or any third party.

Proof of purchase is required to enable you to benefit from this warranty.

This warranty will not apply if SmartAngle has been damaged or misused.

About SmartAngle®

  • SmartAngle is a development of Quite Useful Stuff Ltd (QUS).
  • SmartAngle is a registered design of QUS.
  • "SmartAngle" is a registered trademark of QUS.
  • "SmartAngle: measure there, read here" is a registered trademark of QUS.
  • "SmartAngle: an extra hand when levelling" is a registered trademark of QUS.
  • SmartAngle firmware and software ("the SmartAngle app") are copyright by QUS.