AlterLock CycleGuardService

#2 Report on the development of AlterLock

Please see the following article for the first part.

About sound volume of the alarm

The anti-theft alarm is one of the main functions of Alterlock. And we have received some demands from V1 users.

So we have tried to increase the sound and reached approximately 3 times (+10Db)of V1. There is some way to increase the sound volume. Raise the voltage, expand the space for the resonance and get bigger the buzzer size. It was tough in the thinner design. But we are trying so hard on this to realize the update.

We do not know whether it is enough, the circumstances are case by case. But we believe that we reach the purpose of increasing the sound to enhance theft deterrence.

We assume it is so easy to destroy the physical keys and take the vehicle away.However, Criminals flee the scene if they think the alarm will go off and the owner will come running, making the alarm a very effective deterrent.

On the other hand, no matter how loud the alarm is, Passers-by do not catch bicycle thieves. It is important that you are ready to respond as soon as the alarm goes off and you receive a notification on your phone.

Concerns and solutions for louder alarms

If you are familiar with the current version, you may have accidentally set off the alarm yourself or when someone bumps into you on the bike rack.

We have heard people say they have been bothered by their family or neighbors and embarrassed. Even I, the developer, sometimes forgot to disarm the alarm and it went off, so it was a problem I wanted to solve.

The second version of AlterLock responds to this problem by making the first alarm sound a relatively small warning sound. This feature can of course be turned on and off from the app. Also, in the current version, when in lock mode, the alarm will sound repeatedly when vibrated, after an interval of a few minutes.

In the unlikely event of a smartphone breaking or failing to pair, there was the fear of having to ride with the alarm going off, and in the unlikely event of theft, there was also the fear that the alarm would go off endlessly, attracting the attention of criminals who could then destroy the device.

To address this issue, it is now possible to limit the number of times the alarm will go off in response to vibration. As before, multiple alarms will still deter the perpetrator, but after that it will only be possible to track the location in stealth.

There are also improvements to be made to the frequency of communication and the accuracy of the location data, which we hope to report on next time.

About antenna testing

For the second version of AlterLock, the antenna board became very small to make the housing thinner, and because of the interference from other components, it was difficult to ensure the radiation efficiency of the antenna.

As we are not an expert in antennas, we brought in an expert who had led antenna R&D at a world-famous smartphone manufacturer to help us select the best antenna and repeatedly test and adjust it.

Of course, this is not a simple antenna test. We also considered the effects of different frame materials, the presence of a bottle cage, bottles, water, and tools in the bottle, etc., to achieve the maximum antenna efficiency, so that cyclists can use it without any problems. (Although it is best to remove the bottle if it's full of water...)

As a result, both Sigfox transmission and GPS reception are higher than with the current version. We have also made some changes to the shape of the housing and the mounting method, which we will be able to show you when the machined device is ready.


We have spent a lot of time on the alarm and antenna, but we are also making good progress on the app and firmware. We hope to be able to share more about that in the next issue. Until next time, enjoy the summer cycle life.

*Please note that all information might be changed before the release.