Hi everyone,
I'm building a wearable project using an Arduino Nano . The system includes several modules: MAX30102 (heart rate, SpO₂, temperature sensor), GSR sensor, HC-06 Bluetooth module, and a buzzer.
My concern is whether connecting the 3.7V battery directly to the Nano (through VIN, 3,3V or 5V pin) can reliably power all these components. I want to make sure that voltage levels remain stable and that each sensor receives the correct voltage for accurate readings. Wherese HC-05 used 5V pin.
Can I power the Nano directly from 3.7V ? And if so whitch pin should i use.
I should use 3,3v battery because the size of the bettery is important for my project.
Any suggestions or example circuits would be appreciated.
There are about a half dozen boards called Arduino Nano. Which one do you have?
If it is the "classic Nano", then it can be powered at 3.7V via the 5V pin, but that may not work with the other modules. To get 5V from the battery, use a step up converter. This one will work.
Once you determine which of the 11 Nano modules you will be using, look at the Tech Specs and find the current per pin (basic Nano is 20mA) now check that each sensor is less than that value. Add up all the sensor current requirements and make sure it does not exceed the Nano total.
You would likely get in troubles when battery charge level is going below 50% (if not before).
3.3V battery would be a challenge, and if you mean some coin type battery, you have no hope with that setup.
Battery voltage is never 'stable'. All batteries, when fully charged, start to lose voltage the moment it is removed from the charger. In your case, I am guessing it is a 18650 LiOn cell, so it starts at 4.2 to 4.2V. It will quickly drop to the nominal voltage of 3.6V to 3.7V, which is too low to drive a step-up converter. Normally, people use two batteries in series, so you start at about 8V and quickly drop to 7.4, where it will stay relatively flat, but a step up needs a minimum of about 1V to 1.5V higher than the output.
It's all guesswork until you post the datasheet for each sensor, tell us which of many NANO's and precisely what battery keeping in mind the 18650 cell is the most faked thing on the market.
At the moment your setup will not work for very long.
Firstable thank you,
My arduino nano is like the one in the link : https://docs.arduino.cc/hardware/nano/
I will upload the battery image so you can check out :
There are a few questions asked but not answered.
What is the total max current all the components will draw other than the Nano?
What will you use to recharge the battery and how often.
Generally speaking, in all but the most trivial circuits TWO power supplies are needed, one just for the Nano and one for all the other components but sometimes even more than one if motors are involved unless the PSU is robust (plugged into wall). You can use a single physical PSU and spit off the two logical PSUs.
While there are boost converters that can produce 5VDC from 3.75VDC (the flat part of the LiPO curve) the battery life will be greatly reduced as more current is drawn from the battery to create the higher voltage. You would be much wiser to use one of the 3.3VDC Arduino Nano's or switch to a different 3.3VDC board family.
