How Does it Work?
1- The solenoid valve is closed when the device is powered off so no water can flow if the regulator is not running.
2- The valve opens when the device is powered on; the user can turn on the water now.
3- The regulator allows the water to warm-up for 20 seconds (is adjustable) indicated by 1 beep.
4- After warm-up, the regulator begins the shower timer for 5 minutes (is adjustable) indicated by 2 beeps.
5- The regulator will give 1 beep warnings 1 and 2 minutes before the shower is over.
6- Once the shower time is completed, the device will automatically close the valve, stopping the flow of water. The user can turn off the water and the regulator now. This is indicated by a continuous beep.
Featured Adafruit Product!
RGB backlight positive LCD 16×2 + extras – black on RGB: This is a fancy upgrade to standard 16×2 LCDs, instead of just having blue and white, or red and black, this LCD has black characters on a full color RGB-backlight background! That means you can change the background color to anything you want – red, green, blue, pink, white, purple yellow, teal, salmon, chartreuse, or just leave it off for a neutral background. This LCD is the most daylight readable character LCD we have and is very beautiful and easy to read no matter what color/brighness you have for the backlight. (read more)
Source: Adafruit – Raspberry