Hi everyone,
I’m working on a personal project and would love some help from the community.
I want to turn a regular water bottle into a “smart” one that reminds me to drink water throughout the day. I’m not looking to buy a commercial smart bottle—I’d rather build a simple DIY version myself.

The bottle I'm using has a removable silicone cover (see image attached), so I’m thinking of placing the circuit inside a small puck (about 3 inches in diameter) that fits between the bottle and the silicone cover at the bottom.

What I’m hoping to build:

• A system that detects when I’ve picked up the bottle— I'm thinking using a photoresistor (LDR) to sense light changes when the bottom is exposed.
• If no activity is detected for a certain period, it should trigger a small buzzer as a reminder.
• The whole setup should be compact and rechargeable, and fit discreetly under the bottle without affecting daily use.

I’d really appreciate Schematics or wiring diagrams and parts list for a basic version of this idea and any suggestions to improve or simplify the overall approach
This is mainly for personal health and as a fun weekend project to help me stay on top of hydration.
Thanks so much in advance!

— Thomas

 

If no activity is detected for a certain period, it should trigger a small buzzer

How long a period?

How to turn off the buzzer?

 

Good questions! Let’s go with this logic:

• If I haven’t had a drink in 30 minutes, the buzzer should buzz once every 5 minutes until I drink water again.
• As soon as I drink, the timer resets and the 30-minute countdown starts over.

 

Surely the buzzer reset of your system needs to take account of the quantity consumed? Perhaps an accelerometer-based weight determination so the buzzer resets when sufficient water has been removed from the bottle. Otherwise the risk of an unnoticed increasing water deficit exists.

 

I considered that, but I’d rather keep things as simple as possible. For my use case, I don’t need to track the amount consumed—when I drink water, I usually drink a fair bit.
I’m also aware that simply lifting the bottle (for example, to move it from one room to another) could reset the timer, even if I haven’t actually taken a sip. That’s a limitation I’m okay with for now.

 

The body already has an alarm for needing water, it is called thirst.

If you are drinking water when you are not thirsty, you are probably drinking too much water.

 

Hi everyone,
I’m working on a personal project and would love some help from the community.
I want to turn a regular water bottle into a “smart” one that reminds me to drink water throughout the day. I’m not looking to buy a commercial smart bottle—I’d rather build a simple DIY version myself.

The bottle I'm using has a removable silicone cover (see image attached), so I’m thinking of placing the circuit inside a small puck (about 3 inches in diameter) that fits between the bottle and the silicone cover at the bottom.

What I’m hoping to build:

• A system that detects when I’ve picked up the bottle— I'm thinking using a photoresistor (LDR) to sense light changes when the bottom is exposed.
• If no activity is detected for a certain period, it should trigger a small buzzer as a reminder.
• The whole setup should be compact and rechargeable, and fit discreetly under the bottle without affecting daily use.

I’d really appreciate Schematics or wiring diagrams and parts list for a basic version of this idea and any suggestions to improve or simplify the overall approach
This is mainly for personal health and as a fun weekend project to help me stay on top of hydration.
Thanks so much in advance!

— Thomas


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Given what you have to work with it is my expectation that any design relying an an autonomous sensor will prove impractical.

To do what you want reliably, you would need a multimode sensor array, or a bespoke water bottle that handled the detection mechanically to trigger your circuit.

I would suggest you make something with a button that you press when you take a drink.

 

The body already has an alarm for needing water, it is called thirst.

If you are drinking water when you are not thirsty, you are probably drinking too much water.

Some people (I am one) do not get adequate thirst signals to interrupt other activities.

For me this is particularly problematic because I am very prone to kidney stones so I really need to drink enough.

 

As much as I respect your opinion, I am going with the expert rather than your personal anecdote. If the TS has a rare medical condition, I think he should have mentioned it. The fact is, that it is trendy to be obsessed about hydration, and such people are dying from over hydration, when dehydration is not life threatening.

From the article.

The notion that you should drink to prevent thirst makes no sense. Humans don’t need to be told when and how much to drink (except in rare medical circumstances). Thirst is our innate hydration sensor.

 

small MCU, button (or two electrodes that make skin contact), coin cell battery and piezo buzzer. the entire thing could be very thin.

 

That's not a peer-reviewed article and is just the opinions of one person, albeit a nephrologist. Maybe a step above anecdotes.

Most people, particularly the sedentary, are dehydrated. If you get up and move around, you'll quickly experience thirst but for some reason, that thirst urge is too quiet if we're physically idle. This phenomenon gets more prevalent with age. People with sedentary lifestyles - the modern office worker, for instance - need to actively hydrate. Not the crazy gallon-per-day forcing, just a glass when you wake up and an occasional glass throughout the day. Urine color is an excellent indicator of your hydration level.

I think this project would be much simpler with just a resettable timer - no sensors. My first thought was accelerometer but there's just no need for complication. The timer counts down, the alert goes off, the user takes a drink and hits the switch to restart the process.

The mechanical issues of a switch that is super convenient are probably the bigger challenge here. I think an accelerating alert would make sense too, for instance an LED at first, then throbbing, maybe then flashing, then beeping and flashing, etc.

 

I would be happy with the "timer counts down, the alert goes off, the user takes a drink and hits the switch to restart the process." solution.

 

As much as I respect your opinion, I am going with the expert rather than your personal anecdote. If the TS has a rare medical condition, I think he should have mentioned it. The fact is, that it is trendy to be obsessed about hydration, and such people are dying from over hydration, when dehydration is not life threatening.

From the article.

Why would there be a need for me to mention if I have a "rare medical condition" in an electronics forum?

 

I would be happy with the "timer counts down, the alert goes off, the user takes a drink and hits the switch to restart the process." solution.

OK, then there are two branches to work on, the physical/mechanical and the electrical. The circuitry to accomplish this is "simple" however I think you'll want to minimize power so that you can minimize the battery size.

I think most of the advice you'll hear is to use a micro. It would give you control and flexibility at the expense of the learning curve if you haven't already used one.

There are tons of 555 timer IC based countdown timer circuits and that would certainly work here. In fact if you want to bang out a prototype and save the micro for a later version, that's a perfectly valid approach. You could spend more time on finding the right switch, the right alert, and solving the mechanical issues.

Do you have a time interval in mind? The 555 isn't great once you get into the range of minutes or more, so maybe it's not such a good place to start after all.

 

• If I haven’t had a drink in 30 minutes, the buzzer should buzz once every 5 minutes until I drink water again.
• As soon as I drink, the timer resets and the 30-minute countdown starts over.

 

As much as I respect your opinion, I am going with the expert rather than your personal anecdote. If the TS has a rare medical condition, I think he should have mentioned it. The fact is, that it is trendy to be obsessed about hydration, and such people are dying from over hydration, when dehydration is not life threatening.

From the article.

I am not able to find the logic of your opening sentence. I said some people don't have an adequate thirst signal, not that it is impossible to over-hydrate.

I made no argument in favor of arbitrary consumption of water.

 

Why would there be a need for me to mention if I have a "rare medical condition" in an electronics forum?

In case you hadn't picked up on it, there is considerable scepticism around the need to hydrate beyond the normal driver of thirst. Ya'akov has said he attempts to be generously hydrated to manage kidney stones, and I personally also drink beyond ordinary thirst to try to manage gout, but there are dangers associated with excessive hydration as there is no equivalent of thirst that tells you to STOP drinking.

I find it extraordinary that you need to drink at a regulated every 30 minutes if you DONT have a medical condition that prescribes that as it seems to be a regime that fails to account for variances in need with activity level (as ordinary thirst would).

Having said all that, good luck with your water bottle project.

 

In case you hadn't picked up on it, there is considerable scepticism around the need to hydrate beyond the normal driver of thirst. Ya'akov has said he attempts to be generously hydrated to manage kidney stones, and I personally also drink beyond ordinary thirst to try to manage gout, but there are dangers associated with excessive hydration as there is no equivalent of thirst that tells you to STOP drinking.

I find it extraordinary that you need to drink at a regulated every 30 minutes if you DONT have a medical condition that prescribes that as it seems to be a regime that fails to account for variances in need with activity level (as ordinary thirst would).

Having said all that, good luck with your water bottle project.

Good luck to you too boostbuck.

 

In case you hadn't picked up on it, there is considerable scepticism around the need to hydrate beyond the normal driver of thirst.

Indeed there is, and I should have provided multiple links. This hydration myth is another example of fitness and nutrition “experts” doing religion instead of science.

 

Why would there be a need for me to mention if I have a "rare medical condition" in an electronics forum?

When proposing a project, justifying the need for it is an essential consideration. Particularly when the usage of it might be harmful.