daniel.schaaaf 177 Posted October 27, 2020 Share Posted October 27, 2020 (edited) Since i got my Pro1, the proximity sensor (light sensor) is one of my biggest sources of irritation. Both on the original Android and on LOS, it prevents me from making phone calls without inadvertently hanging up or changing the screen brightness. The proximity sensor does not always register my ear pressed to the loudspeaker, the screen switches on, and the touchscreen registers touches from my earlobe and cheek. This happens with the phone app as well as with the Signal messenger, but it might be worse with Signal. With the app DevCheck, I found that the proximity sensor (TXC PA22A) only reports two states, "near" and "far" or "0cm" and "5cm". The 5cm actually being 3cm measured. Just for fun, I tested the proximity sensor on my Moto Z Play, and it reports three distances, "100cm", "3cm", and "1cm". The distances measured as >3cm, 3cm, and <3cm. The interesting thing is that the sensor in the Moto Z Play uses hysteresis to prevent the screen from switching on involuntarily. You can move a finger back and forth between "100cm" and "3cm" and the change gets registered immediately. However, once you reach "1cm", you are locked in and have to move your finger to "100cm" to register a proximity change again. You cannot toggle between "1cm" and "3cm". Is it possible to implement hysteresis with the PA22A? Or does the sensor only register two proximity states? If we only have two proximity states, what can be done to prevent the screen to switch on while making a call? According to the manufacturer (http://www.txccorp.com/download/products/sensors/2015TXC_PA22A_120.pdf) the sensor has "<3 steps" for "ALS_Dark". To me this reads as two steps in darkness by using the built-in infrared diode. Even though it seems strange to me to write "2 steps" as "<3 steps". Another interesting thing to look at would be how the screen is turned on or off programmatically. Why does the screen turn back on, even though my ear is covering the sensor? Is a proximity check failing at some time? Does the proximity sensor deliver false information? Should the output of the proximity sensor be checked several times before switching on the screen? If we cannot implement "hardware hysteresis with three proximity states", can we introduce a timeout and an additional proximity check at the end of the timeout? When i want to end a call, the screen usually remains black for 2-3s, which suggests there is a (way too long) timeout implemented already. But it seems to fail during a call? Sorry for all those questions. I would really like this to be sorted out though. Next to the fingerprint sensor, the proximity sensor failing is just not acceptable. After all, the Pro1 is supposed to be a phone and I should be able to use it as such (Btw., I am writing "I" here because I don't know if other people are bothered by the proximity sensor as much ...) Edited October 27, 2020 by daniel.schaaaf 8 Quote Link to post Share on other sites
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