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Topic: Best arduino for something that is being worn (Read 1 time) previous topic - next topic

Palmer21

Jan 11, 2019, 03:58 pm Last Edit: Jan 11, 2019, 03:59 pm by Palmer21
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?

srnet

Think ............ maybe the best Arduino to use depends on what you want the bracelet to do ?
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

jremington


srnet

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.
$50SAT is now Silent (but probably still running)
http://www.50dollarsat.info/
http://www.loratracker.uk/

jremington

#4
Jan 11, 2019, 04:43 pm Last Edit: Jan 11, 2019, 04:46 pm by jremington
The processor chip fits into a bracelet. Design your own PCB, or use a large bracelet, like this:


Willpatel_Kendmirez

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.


GoForSmoke

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.
1) http://gammon.com.au/blink  <-- tasking Arduino 1-2-3
2) http://gammon.com.au/serial <-- techniques howto
3) http://gammon.com.au/interrupts
Your sketch can sense ongoing process events in time.
Your sketch can make events to control it over time.

GoForSmoke

I don't know where you shop, did you try eBay?
https://www.ebay.com/sch/i.html?_nkw=esp8266+arduino&ul_noapp=true&_sop=15

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:
https://www.ebay.com/itm/ESP8266-Serial-WIFI-Wireless-Transceiver-Module-Send-Receive-AP-STA-Arduino-XT-C/112043056573?_trkparms=aid%3D222007%26algo%3DSIM.MBE%26ao%3D1%26asc%3D20131231084308%26meid%3D695ea2ac6276459a8db619580e324203%26pid%3D100010%26rk%3D2%26rkt%3D12%26sd%3D254077247396%26itm%3D112043056573&_trksid=p2047675.c100010.m2109

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)
https://www.ebay.com/cln/gergely87hu/lilypad-arduino/299497353016

Arduino Mini and other small boards do come in versions w/o pins, connect straight to the small low profile board.
https://www.dx.com/p/open-smart-mini-atmega328p-3-3v-8mhz-development-board-for-arduino-2075088#.XEIkF63gU5Q

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.
1) http://gammon.com.au/blink  <-- tasking Arduino 1-2-3
2) http://gammon.com.au/serial <-- techniques howto
3) http://gammon.com.au/interrupts
Your sketch can sense ongoing process events in time.
Your sketch can make events to control it over time.

westfw

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.


GoForSmoke

The O'Baka Arduino is a 328P DIP with components soldered to the legs.
https://make.kosakalab.com/arduino/obaka/project-2/index_en.html

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.   
1) http://gammon.com.au/blink  <-- tasking Arduino 1-2-3
2) http://gammon.com.au/serial <-- techniques howto
3) http://gammon.com.au/interrupts
Your sketch can sense ongoing process events in time.
Your sketch can make events to control it over time.

wvmarle

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.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

wvmarle

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.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

wvmarle

Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

wvmarle

Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

wvmarle

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.
Quality of answers is related to the quality of questions. Good questions will get good answers. Useless answers are a sign of a poor question.

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