Monitoring a CR2032 voltage

[philgib]

Good day guys,

I am trying to monitor the CR2032 battery voltage so that I can switch a red LED on when voltage is going under 2.98V

I thought that trying to read the VIN would be the best way, but there is maybe a better one ?

I made a previous search on the subject on the forum before posting, and all I find is the advice to use a voltage divider, but I do not understand how to implement it.

Thank you

[anon57585045]

@philgib

I am trying to monitor the CR2032 battery voltage so that I can switch a red LED on when voltage is going under 2.98V

Won't the LED drain the battery when it's already almost exhausted?

but I do not understand how to implement it.

What do you not understand? If you don't say, you'll just get a repetition of all the stuff you didn't understand...

Don't suggest that Arduino voltage divider implementations are not common... they are all over the place...

[johnerrington]

You havent told us: what components you are using - with links:
or - pretty much ANYTHING else.

So start here:

How to get the best out of this forum

See also FAQ - Arduino Forum for general rules on forum behaviour and etiquette. Hello, Welcome to the Arduino Forum. This guide explains how to get the best out of this forum. Please read and follow the instructions below. Being new here you might think this is having rules for the sake of rules, but that is not the case. If you don’t follow the guidelines all that happens is there is a long exchange of posts while we try to get you to tell us what we need in order to help you, which is fru…

and here

How to make a schematic you can post.

When you submit a question on the forum you will usually need to add a schematic (circuit diagram). The tutorial that follows will explain some ways to create a useful image; however lets start by explaining how to add the image to your post. Its easy. Having created the image all you need to do is : Save the image somewhere convenient - maybe your desktop Start your post, and place the cursor (insertion point) where you want the image to be shown; [upload image to forum] 3: click th…

[philgib]

Aarg, be aware that most of your recent answers at least to my posts sound really patronizing / bullying.

It just kills right a the start any good will from new comers like me who are overwhelmed by the learning curve but still want to learn.

So either help with a positive attitude because you are happy to or please just skip / ignore my posts.

Thank you.

[philgib]

Hi John,

I am not sure any schematic would help here since there is none.
I am just asking if there is any code line which would allow to read the voltage coming into an arduino ?

[runaway_pancake]

@philgib

I am just asking if there is any code line which would allow to read the voltage coming into an arduino ?

analogRead() - Arduino Reference

@philgib

I made a previous search on the subject... and all I find is the advice to use a voltage divider, ....

If you're using a UNO, no 'voltage divider' is required.

[anon57585045]

@philgib

It just kills right a the start any good will from new comers like me who are overwhelmed by the learning curve but still want to learn.

Any newcomer that takes the time to understand the forum protocols, and follows in particular the aspect that sufficient information should be provided in the beginning, will maintain my good will. I'm even comfortable with waiving that for a while in a thread, while things get sorted out. But you've been here long enough already to learn how to do that, and you still aren't. So you might get patronizing or bullying-seeming replies when people get frustrated with you. But I will be happy to block you. Done.

[herbschwarz]

That type battery is sold with the understanding that it has a 10 year shelf life. They have a self discharge rate of about 1% per year. So if you do not apply an external load to the battery, it will take a long, long time to discharge and light the LED.

[anon57585045]

@runaway_pancake

If you're using a UNO, no 'voltage divider' is required.

...but a current limiter is.

[runaway_pancake]

@anon57585045

...but

I thought you dropped carrier

[johnerrington]

@philgib

I am not sure any schematic would help here since there is none.

Thats why it would help. We have no idea of what your battery is connected to.

@philgib

I am just asking if there is any code line which would allow to read the voltage coming into an arduino ?

WHAT Arduino? (show on the schematic, as I assume its connected to the battery? Maybe as a source of power? or just an input voltage to be measured?)

[anon57585045]

@runaway_pancake

I thought you dropped carrier

It was a line glitch.

[Idahowalker]

In the end, for me after making many voltage dividers and current measurement things to read the battery's thingies, with the idea being to extend as much as possible battery life, I find the current consumption of those things to be far to limiting to prolonged battery life to include them in working projects; like a weather station or a hexapod.

[Paul_B]

Point is, the OP does appear to be more interested in some form of "political correctness" than providing information essential to the provision of meaningful answers.

[philgib]

Appreciate your straight forward answer, thank you Runaway

You just made me realize that actually most signals coming into Arduinos are plain voltage readings... That is what I am talking about when mentioning a steep learning curve