My airbed developed a small leak that 1. is impossible to find and 2. impossible to fix if I somehow found it, so my bed will leak down in a few hours and I wake up with a sore back from sleeping on a too soft mattress. I built and programmed this device using an Arduino microcontroller with a real time clock and connected it to my bed's inflation control. Now, during the night the controller initiates a refill cycle every 2½ hours until rising time in the morning and then does nothing until bed time the next night. I've got a switch on it to change the refill times for daylight saving time when it's needed. This handy little gadget won't win any beauty prizes but it works great and I wake up all bushy eyed and bright tailed, ready to do what needs to be done.