My alarm clock consists of an ESP32 and has a somewhat big LED-array connected to it (powered by a transistor), a buzzer and a PIR sensor. It doesn't show the time, but buzzes (and flashes) and takes care of slowly brightening the room, or at night slowly dimming it into darkness some time after all the lights have been turned off.
One added benefit I discovered afterwards is that even though the AP is not between me and the ESP, I seem to reflect enough RF so that logging the RSSI provides information not only about when I'm in the bed, but also when I change position at night.
The green one in the middle is the RSSI, the yellow at the bottom the PIR sensor, the top one a mix of the data from my Mi Band 3 plus an annotation of when I was in bed (yes I did spend a lot of time reading news before falling asleep and before getting up)
One added benefit I discovered afterwards is that even though the AP is not between me and the ESP, I seem to reflect enough RF so that logging the RSSI provides information not only about when I'm in the bed, but also when I change position at night.
https://imgur.com/a/VixOlu5 (edit: no erotic content despite the warning)
The green one in the middle is the RSSI, the yellow at the bottom the PIR sensor, the top one a mix of the data from my Mi Band 3 plus an annotation of when I was in bed (yes I did spend a lot of time reading news before falling asleep and before getting up)