Here's a nifty project I came up with to help the people at home. It's a system that checks the waterlevel of an overhead tank and sends the data using radio frequency wireless modules. There are some LEDs on the receiving unit which indicate the waterlevel and a piezo speaker which alerts when the tank is empty or is about to overflow.
First attempt using RF encoder chips. Antenna for the RF module has been ‘wound’ around the transmitter because I found that it (wierdly) increased the range.
Receiver end with RF decoder chip. White LED shows that a valid transmission has taken place.
Improvised version with hardware encoders replaced with software encoding using atmega8 (programmed in Arduino)
After major struggles with antenna selection, went with a coil of wire taken from a mini transformer.
Couldn’t resist fixing the transmitter case with some scrap aluminum sheet. Dont know if it’s doing a great job but hopefully will reflect out the heat.
Being tested at at range of 12m and reading the data loud and clear
Final version with lots of changes in code to prolong battery life. Tested at a range of 20 meters at 5V.
Don’t forget to test the range with and without that aluminium foil covering… depending on how the transmitter and receiver are oriented you might find it decreases the effective broadcast strength.
Remote water tank level indicator. Do many houses in America have water storage tanks? Theyre quite common here in Australia. In fact Ive been thinking of doing the same thing for our tanks but including flow meters as well.
Most of the buildings in my country have an overhead tank placed on the terrace that supplies water to the floors below. The water is usually pumped to the overhead tank using a waterpump or motor which is usually located in the ground floor or basement. The process of filling up the tank is completely manual in most cases, where some person (security guard / watchman / annoyed resident on the ground floor/etc…) keeps checking if the water pressure is low and then switches the motor on. After some time, the overhead tank overflows and there’s a huge gushing waterfall and insane wastage of water, thanks to the absent-minded security guard, who has gone who-knows-where to have tea and gossip. Eventually, the resident located right under the torrential downpour starts yelling, and the motor is finally switched off by someone in the vicinity.
So what I’ve made is a device that sits right outside the overhead tank with just the sensors placed inside it, to monitor the level of water. I’ve tried various sensors (Maxbotix Ultrasound, homemade infrared, simple contact electrode method) and all of them work just fine. Data from the sensor is streamed wirelessly through RF modules. This is received in another unit placed on the ground floor, decoded and the water level is indicated using LEDs/LCD/etc. It also has a speaker that makes sounds when the waterlevel drops below a certain level or when the tank is about to get full and overflow. In this way it alerts the person in-charge of handling the waterpumping system.
I’m currently working on taking it to the next level and interface the receiver to the motor, with relays. It would then become a completely autonomous water pumping system with the option of manual control. Will try that soon and see how it turns out.
