Best arduino for something that is being worn

I need to know what is the best arduino to use to program something that is going is going to be in a bracelet. This is a college project of mine so any suggestions please?

Think ............ maybe the best Arduino to use depends on what you want the bracelet to do ?

These are made to be sewn into clothing.

Thank you for that! But I am more looking for something that is can almost fit into the size of a fitbit.

Useful information to have included in your first post, the more details of your project you can reveal, the better the advice, saves a lot of time too.

The processor chip fits into a bracelet. Design your own PCB, or use a large bracelet, like this:

The specification for me to achieve a distinction does not need the project to function.

What? That's unusual; at most schools I'd think that even to pass it needs to function.

If you can learn to solder surface mount components then you can use boards the size of a finger end-joint.

You might want to look into ESP8266 modules, they're about that small and have low power wifi built in. You might even find a button cell just right for it.

I don't know where you shop, did you try eBay?

Take care if you want pins or pads to connect to, wifi modules run $1.25 ea but boards with pins are coser to $2.

ESP8266 has few IO pins and usually dedicated to wifi. The controller has a fast 32 bit cpu with less than cramped RAM capable of running a good deal more than just wifi.

The ones I bought are smaller than the end of my pinky and have small pins, they look like the module here for US$1.60:

The NodeMCU boards shown on the 1st link are more board friendly but less wear friendly.

Lilypad is most wear friendly, look for bulk deals (not at that link)

Arduino Mini and other small boards do come in versions w/o pins, connect straight to the small low profile board.

Try Aliexpress, look for bulk deals then sell enough that yours are free. Everybody needs one.

If anyone in your group can learn to solder surface mount (hobby tools may include electric skillet or toaster over) it has real value. The small and newest chips are all surface mount. If you can get a DIP version it costs more. Make should be marketable even at small scale, just don't breathe the frikking fumes don't let them dissipate inside! Exit venting is a must.

Smaller than the Adafruit Flora or Sparkfun Lilypads are the Gemma and LilyTiny
However, these are still "board-level" wearables, designed to be connected with jumper wires and conductive thread and similar, so they're all significantly larger than chips themselves, with amenities like battery connectors, big holes for wrapping thread around, an so on.
If you want something "fitbit sized", you probably need to be looking at dealing with bare chips. The same ATmega328p used on Uno (and thus SW compatible) is available in packages down to about 5mm square that aren't quite "impossible for humans" to assemble, and some of the other chips (attiny85, attiny841) supported by 3rd party packages (ATtinyCore) are available is pretty beginner-friendly (but still pretty tiny) SOIC packages.

The O'Baka Arduino is a 328P DIP with components soldered to the legs.

If you reduce that to minimal internal clock version and bend the legs out to the sides it'd be pretty flat. Wire it up and glue it to a base for strain relief. When you're sure it's solid, seal it over. Check Mouser for price, the -PU's were cheapest DIP 328P last I saw at around $2.15 for 1 and breaks for bulk, 10+ etc.

The chip needs power/ground/bypass cap(s)/reset to run and even reset may be optional (it is for ATtiny45/85) meaning 2 wires and 2 capacitors and a program to minimum get it going at 8 MHz or less. 8 MHz can run at 3V, lower speeds can run at less and might match a desired coin cell voltage. Minimal chip running is not exciting, you gotta hook exciting things up to it.

ESP8266 needs peak currents of a couple hundred mA so powering using a button cell is going to be really hard. That's also why it needs a 100 nF bypass cap and a 100 µF decoupling cap for proper operation.

What in terms of beginner friendly. Are they easy to code or to wire up?

I found the ATtiny range pretty easy to program - code wise they're very similar to the Uno (just some minor differences, mostly in the number of available pins, timers, that kind of thing); upload wise it's quite straightforward with the ISP interface (and use a spare Arduino as programmer).

To wire up, that highly depends on your skill set. The dimensions of all those parts are given in their respective data sheets, look it up. SOIC parts can be hand soldered though reflow is much easier and more reliable. I prefer to prototype with DIP parts but not all tiny's are available in DIP so I soldered a few on adapter boards so they can go on a solderless breadboard.

Arduino IDE with the ATtinyCore.


If you can't get the core downloaded you're not going to be able to program it.

As said, differences are small. Less pins, less (for e.g. the 13 and 85) or more (for e.g. the 841) timers, less memory to work with, etc. Check the Atmel web site for a complete overview.

What would you do step by step with minimal funds to make this product? I just wanna take in what others would do from the beginning and see how far I can go with that.

You want to wear Arduino is all I have remembered. Maybe as a wrist device.

Look on AliExpress for small, cheap Nanos and Minis but watch which chip they put on, the 168P has half the memory/flash/EEPROM as the 328P Uno/Nano/Mini standard and some boards have ATmega8's with maybe 512 or 256 bytes of RAM, which is suitable for very small jobs. I can get a 168P Nano on AliExpress for less than I can buy a 328P DIP so what's cheaper as long as the job will run on a 168P?

How many end pieces will you make?

There are primitive on/off radio modules that can do the job, you would not need an MCU to send from one to a receiver as a button would do.

I am confused by all the talk of wifi and radios. Is the buzzer in a remote location, or is it part of the bracelet. If you want a timer bracelet, then a tiny 85, rtc chip oled display, piezo buzzer and a 100mAh lipo should accomplish what you need. The whole thing will be about twice the size of an actual fitbit.

If you want a remote response, then it will need to be bigger.

A few years ago, since 2011 I saw Youtube covering a very simple radio module that what sounded like short buzzes on a radio, had no protocol or port just ON / OFF. But they were really cheap.

Now you might get an nRF short range wifi transmit and receive pair for less than $3 then need a controller at each end where with dead simple the sender needs a button and the receiver triggers the relay. If you have a wrist radio receiver and tune it to an empty band, a close, low powered radio transmitter tuned to the same band could send the sound for the wrist device live.

Is it possible to be able to control the signal through a phone if I code a simple app.

That requires bluetooth or wifi to the phone, not the cheap simple but the cost more solution.