Category: Mobile Computing Tips

Troubleshooting in-app QR-code scanning on your phone

Service Victoria contact-tracing QR code sign at Fairfield Primary School

The Service Victoria QR-code contact-tracing system was one of those app-based QR code setups that may not work properly if your phone’s QR code recognition subsystem isn’t working

A situation that happened with my Android phone recently was that the Services Victoria QR code app failed to recognise a check-in QR code even though it has normally been doing that before. I had to then resort to entering the venue-specific manual-entry code printed below the QR code on the signage to begin the check-in process for that area.

This problem can also happen with something like WhatsApp, Signal or something similar when you are attempting to bind a desktop or other secondary client device to your service’s account. This also extends to Wi-Fi Easy Connect setups that allow you to enrol your phone or another device in to a desired Wi-Fi network.

It can also happen with book+app setups used with interactive books, second-screen apps that are part of interactive-TV setups, or some app-driven coupon systems that are dependent on recognising QR codes for their functionality. Even setting up app-based multi-factor or password-free authentication is dependent on QR codes when you are provisioning that mobile-based authentication app with an online service.

In use cases like WhatsApp, there may not be any alternative like a human-readable code or an NFC tag to use as an alternative to scanning a QR code. This would then make the app or function useless for its intended purposes.

The situation described here is that a QR-code-dependent app that was previously recognising QR codes for that associated system fails to recognise them.

But how did I troubleshoot this problem further?

A lot of these apps that have QR-code scanning functionality are dependent on functionality within iOS or Android that works with the camera to recognise these codes and make them useful for software on your phone. This is to avoid the need for the software developer to reinvent the wheel when it comes to adding this functionality to their apps.

WhatsApp and Signal's relationship with their desktop clients

.. as can setting up Signal or Whatsapp to work with your regular computer or iPad

But if this fails, the apps that depend on this functionality don’t perform as expected when you attempt to scan a QR code with them. This is even though they have enabled the camera and are passing through the vision to the app’s “viewfinder” window. Of course you might think that the rear camera’s lens is dirty or scratched or you are attempting to scan a poor-quality reproduction of the code.

One way to troubleshoot this kind of situation is to scan this kind of code with a dedicated QR-code scan app that is part of your phone’s operating system. Most Android users would have this as part of the Quick Settings menu. Here, this app has the camera behave in a manner optimised for scanning barcodes and QR codes as if it is called upon by one of these QR-dependent apps.

On some platforms, the Camera app’s QR-code recognition function may behave differently due to it using different in-app software from what is part of your phone’s operating system. This is due to the camera software working on a “photography first” approach rather than a “barcode scanning first” approach.

If this app fails to recognise any QR code, you are dealing with a situation where the software processes associated with QR-code recognition crashing or hanging. This situation may happen with other software on your phone underperforming or behaving in an abnormal manner. Here, you may find that it is a good idea to fully restart your phone, which will effectively get everything to a known point.

In this case, you would have to shut down then restart your phone so as to cause it to fully restart. You should see your phone’s manufacturer or operating system logo appear on the screen as part of the restart process.

After the phone is restarted completely, attempt to scan any QR code with the above-mentioned dedicated QR-code scan app that is part of your phone’s operating system. Usually that will succeed after you have restarted your phone due to the necessary software processes being restarted.

You may have also had to deal with a software update for the QR-code recognition software as part of a software-quality or security update for your phone’s operating system. It is typically to rectify any bugs or security exploits in the affected software or simply to “tune up” the software for better performance.

If that succeeds, attempt to scan the QR code using the app you had problems with so you can identify whether that app is at fault or not. It is also a good idea to check for new versions of this app by visiting your mobile platform’s app store and checking for software updates.

The need for a software update for that app may be due to the app’s developers re-engineering it to take advantage of newer QR-code-recognition software libraries, and may also have to apply for any QR-code-dependent apps on your phone. It is although the revised software libraries are most likely written to support “legacy” application software but offer a “new way in” for newer apps.

In the case of your jurisdiction’s contact-tracing check-in app, you may have to do a Google image search for QR codes relating to that platform. Here, some of these images will represent a sharp-enough representation of a “production” QR code at a known place. Or a club or similar organisation may have set up and posted a “test” or “set-up” code to help members with the onboarding process for the contact-tracing check-in platform.

Conclusion

Your phone not working properly with QR codes may not be just a camera or lens problem but software associated with this functionality that simply had stalled or crashed. Here, you may find that you simply restart your phone to gain full functionality.

How to set Bedtime mode on iOS so you don’t miss important calls

Options area in iOS Bedtime Mode screen

Select Options to set up the Bedtime Mode behaviour

Apple’s iOS operating system since version 12 have support for “Bedtime” mode which allows you to have a good sleep. This is achieved through optimising the display to reduce blue light in a sleep-friendly manner along with default automatic enablement of “Do Not Disturb” mode where the iPhone won’t ring through during the hours the Bedtime mode is in operation. This will be heralded by your iPhone ringing a phrase of Brahms’ Lullaby with a music-box sound when that mode is effective.

But some of us may don’t want to miss important calls that come through at night due to work or personal reasons. An example of this could be a person who is a registered keyholder for a premises and needs to know of alarm incidents affecting that premises. Or someone you expect home may be arriving late and wants to let you know they are on their way or changed plans. In a simple case, you may not want to miss that important call from someone who is on the other side of the world.

The default implementation for Bedtime mode has your iPhone in “Do Not Disturb” mode where your iPhone won’t ring or sound a notification tone for text messages while that mode is in effect. But you may want most of the sleep-friendly benefits of this mode while being able to be woken by those important calls.

iOS Bedtime Mode options screen with Do Not Disturb option called out

Clear the Do Not Disturb option to allow calls and texts to come through during Bedtime Mode

To enable this, you need to go to the Clock app and select the Bedtime screen. Select “Options” and turn off the “Do Not Disturb” mode on that screen to allow calls to come through. The display will still be dimmed through this time but the iPhone will ring or sound a notification tone.

You may also have to check for scheduled “Do Not Disturb” times in case you used this feature to set up a “do-not-disturb” period surrounding your normal bedtime. This is a feature that an iOS user may have implemented before updating to iOS 12. You can check this feature in the “Do Not Disturb” option in the Settings app.

If you do use the “Do Not Disturb” option, you can allow certain caller groups to break through and cause your phone to ring irrespective of when this option is in effect. One of these is “Favourites” which allows you to mark contacts as a “favourite”. Or you can use the Groups option to allow calls from contact groups that you have pre-defined. This is important if you mark out your contacts in to contact groups like “work” or “family” and is a complex procedure that requires you to use your Apple iCloud.com account on a Web browser.

The use of a predefined caller list to override “Do Not Disturb” may not work well with callers who call you using VoIP or from behind a business phone system. This is because you may find that the caller ID for their call may be different from their phone number due to them, for example, calling from the nearest extension rather than their own extension.

iOS and Android could natively follow the Symbian (original Nokia feature-phone operating system) approach where you have different situation-specific alerting presets that affect your phone’s audio / vibration / indicator-light behaviour. This can also allow the use of one or more priority call lists so that callers you select for a particular situation can ring through. Such presets can be linked to operation modes like the “Bedtime” mode or alarm clock so they can be effective during these modes.

As well, Apple could simplify the process of creating and managing caller groups on the iOS contacts list while you are using your iPhone’s user interface. This is important for processes like adding new contacts to your list or revising your contacts, and can make the process more intuitive.