Universal Arduino based distance meter

One way to measure the distance is to use ultrasonic transducer which is cheap and robust. Paoson Woodwork constantly needs to measure distances inside room while installing furniture or doing repair work. So he came up with idea of building an universal distance meter which would measure distances in all four directions at once. He put electronics in to his custom made plywood enclosure where he made openings for sr04 ultrasonic transducers. He put an LCD in front, along with two buttons for unit selection and function. Additionally there is a bubble level tube included to keep things straight when hanging on the wall. All you have to do is to hang the meter on the wall and it displays the distance on LCD for in all four directions. It can display the area of wall with a single button press. There are other programs available along with area and distance. These are Rel – to measure relative distance, Total – to measure total distance between two opposing surfaces. Continue reading

Measuring water level with ultrasound rangefinder

In many applications where water is involved we need to measure water level. There are many ways of measuring water including floaters, capacitance, resistance based meters. More advanced are optical, pressure based methods. Some of them depend on properties of liquid while other are quite universal. If you want reliable method for most cases, the you should stick with non contact methods that doesn’t involve touching devices to liquid. One of great methods involve ultrasound. A simple and cheap rangefinder can do the trick pretty well. PeterHaban have constructed simple water level mater based on well known HC-SR04 Ultrasonic rangefinder module that is attached to Arduino Uno. Ultrasonic module simply measures sound wave propagation time that consists of froward and reflected parts. By knowing time and sound speed in the air it is possible to measure the distance to the object – in this particular case to surface of water. Measurement resolution can reach below centimeter which is really great for most cases. Peter used this level meter on his rainwater harvesting tank. He added this sensor to wireless sensor… Continue reading