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

Wireless liquid level measurement using non contact pressure sensor

Liquid levels can be measured using several methods. Like capacitive, ultrasonic or pressure. Capacitive method limits its use with flammable liquids. Ultrasonic in other hand seems to be to complex for such task. Pressure method is what you need for simple measurements. In following project MPX2010 differential pressure sensor is used where on end is dipped in to liquid using tube. using simple static liquid pressure formula its height can be estimated easily. Design is split in to two parts – transmitting and receiving. So transmitter with sensor can be placed in some radius without worrying about wires. Transmitter and receiver are simple and cheap 433Mhz RF modules. Both parts are powered by MSP430 microcontrollers from TI. Continue reading

Improving water tank pump motor controller

Sameer Guptadesigned a robust water tank filling controller. First circuit is based on simple CMOS logic which detects when water fills the tank using two conductive electrodes. But he wanted to have more control, so he made another version which is based on AT89C2051 microcontroller. Controller does pretty same thing as predecessor, but have more features like blinking LED indicator, sound alarm and of course possibility to add more features. Continue reading

Arduino based capacitive liquid sensor

Water or any other liquid level sensors can be handy around a house. It can be used to monitor a water tank level in a greenhouse or in other areas where liquid level has to be known. The idea is pretty simple – measure a capacitance charge between two metal plates/foils, which varies due liquid level change between them. Of course container has to be non metal. Probably most important part is to read capacitance. For this there is a handy Arduino Capacitive Sensing Library ready for you. To measure capacitance is to measure capacitors charge/discharge time through resistor. Don’t expect great precision with such materials used, but still this is a fun project to try out. Continue reading