How does Sleep as Android (actigraphy) compare to PSG?

PSG = Polysomnography We use a different input than polysomnographists, and define our own sleep phases, reflecting an objective aspect of sleep, easy to measure with common devices. One naturally needs to ask whether there is any relationship between the EEG-phases and our ACT-phases. Fortunately, several research teams raised similar questions before (See this one, or this, or […]

I don’t trust the app – I think it’s generating random data

Accelerometric sensors are really sensitive, which is great for sleep tracking. Normally, what you see when you leave the phone on the table gets immediately dwarfed when you do some more significant move. Just leave phone on the table for a while and you will see a dramatic development, but then move the phone and you will […]

Huawei/Xiaomi sleep tracking interrupted

Huawei together with Xiaomi are the most troubled phones on the market, some vendors tent to ignore Android best practices and implement very bizzare custom modification which make background task nearly impossible to run. Please take a look at

Is sonar safe?

Is sleep tracking with sonar safe for your health? Ultrasound is generally considered safe if it is at normal volume. Regarding health effects, it works in a similar way to normal hearable sound, i.e. very loud ultrasound can damage your hearing, whereas at low volume it is safe to hear. When using speakers, smartphones are […]

Automatic sleep tracking

Sleep as Android doesn’t come with automatic sleep tracking. Actigraphy by itself isn’t a good method to tell if you have fallen asleep. On the other hand, you can setup Sleep as Android to start sleep tracking at specific time, using Tasker. Just install Tasker and create a profile which starts “Start sleep tracking” event […]

No heart rate measurements from my smartwatch

Please check our integrations table – only devices with a  icon will measure heart rate with Sleep as Android. Other smartwatches with HR sensor need to go around SaA – save HR to S Health or Google Fit, from where Sleep as Android will download it. Please note that Sleep as Android downloads the measurements […]

Sleep tracking starts automatically

Please make sure that you are not accidentally starting the Sleep as Android app from your watch. This would start sleep tracking immediately. On Samsung S2, we observed an issue where sleep tracking started really on its own. We have found a solution for the issue, so please uipdate to the latest version of Sleep as […]

Why does the screen turn on during sleep tracking? What to do about it?

Unfortunately, quite a lot Android devices out there do not support gathering accelerometric data (sleep tracking) with screen-off. This is duo to a bug which is on 100% of devices with Android version 1.6 to 2.3.4, on many +2.3.5 device and even on several devices with +4.0. We are doing an automated detection of whether […]