Since we must take care of the water from the internal sinc in our allotment house
I made this arrangement to know when the bucket is full.
The sensor for the water level is a HC-SR04 ultrasonic transmitter/receiver.
It measures the distance to the water surface and displays the result inside the house.
When the bucket is empty there is only one row at the bottom.
When the level reaches maximum the two red LEDs start to flash and the summer beeps.
There is a Nano-board inside and a MAX7219 to drive the display.
(Not to be mixed with external sinc..sync)
(From Tektronix video monitor 650)
