Introducing WALT: A Google Tool For Checking Responsiveness In Android and Chrome OS
Google has an in-house tool that allows mobile users to test the audio and touch latency commands for Android and Chromebook products, and the tech giant has publicly posted it recently, with the hope that by making the tool readily accessible to anyone, the industry as a whole can improve and make way for even better responding mobile devices.
Evolving from Quickstep, the WALT Latency Timer was originally designed to evaluate the responsiveness speed on track pads. Now, it makes use of an external timer, together with the time stamps of events retrieved from the internal timer of the device, in order to generate a more accurate evaluation of the time it takes for the device to respond to input and output.
Google has gamely provided instructions for developers via its Android Developers Blog regarding how to download the source code of the WALT Latency Timer, plus instructions on building the tool. As far as costs are concerned, building the device may not cost more than $50, including securing necessary parts such as a microcontroller board, photo diodes, and accelerometers and lasers to be used for evaluating the latency. Developers can even build a version that measures audio latency only, or touch latency only.
We pretty much take it for granted nowadays, how our mobile device automatically respond to every tap, swipe, or even voice command. The logical assumption is that the faster a mobile device responds to a user’s every move, the better and more powerful (or more useful) it is. Over the years, people have been trying to come up with ways of accurately measuring response time. Naturally, there are many ways in which mobile users can input information into devices, and each input method comes with its own evaluation method. Tap responsiveness can be evaluated with the use of pen like tool that comes with accelerometer, measuring the time it takes for a tap and the response from the device. Scroll or drag responsives can be measure by way of a laser mounted above a touch screen or track pad. As for screen draw latency, photo diodes are used. In evaluating audio latency, this is done by detecting the time when the device outputs a tone until the audio line voltage crosses a certain limit.
For other resources, interested parties can head to the GitHub project page. There they can find instructions on how build the tool, with suggestions for modifications also included in the mix. The Google Play Store also has the WALT Latency Timer mobile app.