Dehydration Water Bottle Alert- Project HELP


Hey I’m a year 12 design and tech student and looking for a way to help prevent dehydration.
I want to make a water bottle attachment that would have a weight sensor at the bottom which you could somehow make go back to zero once its accounted for the weight of the water bottle itself. From there it would weigh the amount of water that goes into the water bottle. And people would be able to set how often they wanted to be alarmed (e.g. 100mL every hour) so then it would deduct the 100g as they drank it- but if the person didn’t reach that limit it would beep or flash. Which means I’d need to have some sort of either buttons for just standard options of how much water they want to drink or some sort of LED screen.

I currently have minimal coding knowledge but we are learning the basics of JAVA in the next couple of weeks. Any help or suggestion and ways to make it happen would be great

Thank you


interesting project, however using weight might not yield the results you require, but maybe something like

Obviously your only wanting a water bottle size and that might not work either! but it was something that sounded similar…

I’ve not got much experience with this side of electronics (still teaching myself as I go along!)


@chosken, welcome. Sounds interesting. I need such a tool today, as I’m on stage in the open, for four hours, at an arts festival, where I’m to be the token expert in the corner. It will be hot.

For mass measurement use a load cell and an instrumentation amplifier. For example;

Mass measurement could work, but it would be hard to compensate and adjust for all the variables. The water container would have to be suspended so that the mass falls entirely on the sensor. If any mass is suspended by something else, the result will be different. Movement would have to be filtered out in software.

I agree with @VK7HSE, there are other ways to solve this. Here are some suggestions;

  • a water flow sensor on the outlet,
  • a capacitive sensor on the outside of the bottle,
  • a resistive sensor on the inside of the bottle (though as it is in contact with the water it has to be certified for that use; human safety and health),
  • infrared reflectance level sensors, every 100ml distance within the bottle,
  • a pair of accelerometers to compare the response to movement of the bottle in relation to the rest of the assembly, assuming it is for someone who is moving,
  • a tiny speaker and microphone at the top of the bottle, with software to slide a tone to find the resonant frequency of the air above the water.

Hope that helps!


Hi Mate,

Some guys at my work have been getting into hydroponics and had some pretty good results with DIY capacitive sensors. similar to this.


I will try and get a hold of some more info.


Ooh, that’s cool. Also keeps the sensor far enough away from the water to keep the water safe. There’s some breakout boards for the MPR121 chip;


Here is the link i mentioned previously. There is a good write up on how it all works,