User Guide

Before you start

  1. You will need the free "TestFlight" app from the Apple app store.

    Apple will send you a code to enable you to download the SmartAngle app.

  2. Remove the three screws on the back of SmartAngle and slowly, firmly and carefully pull the tab out from under the battery. Refit the screws.
  3. The corners of the aluminium level may be very sharp. They can be taken off with a wipe of a sanding block.

Information and tips

  • The app is available for Apple phones/tablets only at the moment - Android will be available very soon.
  • Be careful pulling the battery tab out (see below) - loosen the screws on the back if it won't budge.
  • The app runs in landscape mode only on small screens so the text can be as large as possible. It runs in both portrait and landscape mode on larger screens.
  • Press the button on SmartAngle before loading the app on your phone/tablet. That way your phone won't go to sleep before it has a chance to talk to SmartAngle.
  • Read this User Guide! We know, most people never read the manual then kick themselves wishing they had. It's also a macho thing: "I don't need a manual, I can figure it out for myself!"



  • 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.
  • Remove the three 3mm Pozi #1 screws on the back of SmartAngle, remove the insulation strip and refit the screws.
  • 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.
  • Press the button on SmartAngle - both LEDs will flash three times then the right hand one will flash steadily.
  • Run the SmartAngle app.
  • The app will take a few seconds to connect to SmartAngle.
  • The 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

  • Both LEDs will flash when you press the SmartAngle button then the right hand one will flash about twice a second.
  • It will stay in this state until it connects to the app via Bluetooth.
  • SmartAngle will switch itself off after about 30 seconds if it cannot connect.
  • The right hand LED will flash much slower after SmartAngle connects - about once every two seconds.
  • SmartAngle will switch itself off after about 150 seconds (2.5 minutes).
  • 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 on your phone/tablet will send it to the background and display your home screen.
  • When in the background the app will save battery power by putting SmartAngle to sleep (no LEDs flashing).

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.

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 below shows a stop selected at 22.5 degrees so SmartAngle will provide tones from about 17 degrees to 27 degrees with the tone getting higher the closer it gets to 22.5 degrees. The tone becomes continuous when the stop is reached.

See the Digital Stops section for more details.

Using the camera

The SmartAngle app can take a photograph of SmartAngle in use and superimpose the current reading onto the photo. The image may be used for reference or for sending to a client to indicate progress in a job.

  • Tap the camera icon.
  • Take the photograph.
  • Tap "Use image" - this will return to the main SmartAngle screen.
  • You can view and use the photograph in the normal way from your photo album

The example below shows SmartAngle reading the fall in guttering.

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

Standard stops

Standard stops are provided with the app.

Custom stops

These are create by you and are displayed in the units you selected (degrees, percentage, ratio, mm/m, in/ft) as well as degrees. See below for details about adding custom stops.

Saved hold points

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

Scroll the Digital Stops screen to see stops created in this way - they are shown below the standard and custom stops.

Deleting stops

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

Adding custom 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.

We could have added a circuit to check the battery power - but such a circuit itself uses power and would drain the battery faster.

If the LEDs become very weak, or if weird things start to happen (such as regular disconnection from the app), try changing the 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.

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!

Don't forget, each time you contact us we need to know:

  • Who you are.
  • Your email address.
  • The version of the SmartAngle app and firmware you are using - see the bottom line of the menu screen.


    "app" = software running in your phone/tablet,

    "firmware" = software running inside SmartAngle itself.

  • The make and model of phone/tablet you are using.
  • The version of the operating system you are using on your phone/tablet.

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.