I need help starting; What to buy.

I have a project I want to create and I do not know which board to buy.
I want to create a wearable device (possibly a belt clip) with the following capabilities;

  • can detect light and temperature
    record physical steps of the user
    a clock
    uses a small OLED screen to display information, menu, and animations
    power button for screen only
    3 button interface
    a rechargeable or replaceable (battery) power source
    internal memory for saving progress in case of interrupted power

I know a little context would help with my request. I want to create a fitness aid device. Something that is aware of the world around it through sensing light, temperature, movement, and can tell the time. The ability to count and record steps are important so not only does the device know its moving, the user can meet a fitness goal through its use of counting steps. I would like to display different animations based on sensory input (movement, light, temperature) plus the time of day.
Currently, I am playing around with a Raspberry Pi SenseHat. But it has its limitations for my idea; namely its size and low detail provided by its 8x8 LED screen. I can make it portable; but after adding a battery, detailed screen, and light sensor it is bulky.
I've downloaded Arduino to get started but I need to know the right board before I get very far. I want it small, but size can be sacrificed over safety and functionality. I am fine if the final product ends up the save of a fancy cowboy belt buckle with a thickness of around one inch. At that max size, I could get away with bigger power supply or screen, and use the excess surface to turn it into wearable art.

Besides answering my inquiry; any thoughts, suggestions, and corrections are very welcome.
Thank you.

MrsGatamon:
I have a project I want to create and I do not know which board to buy.
I want to create a wearable device (possibly a belt clip) with the following capabilities;
...

Besides answering my inquiry; any thoughts, suggestions, and corrections are very welcome.
Thank you.

Welcome to the world of Arduino MrsGatamon!

The project you describe seems to be similar to a "fitbit" and is certainly do-able with Arduino technology, but it is far from a starter project!

For the final project, I would suggest that you use a "naked chip" type microcontroller, as it will be much smaller than any board you buy. Otherwise you will need a small board with sufficient pins, say an Arduino nano, or Trinket Pro.

But for your first projects, which are actually necessary for learning how to use the technology, something like an Arduino Uno works well.

Also buy a small oled display, with an I2C or SPI interface, an DS3231 RTC board with an integrated button battery, a light sensor (either photo resistor or transistor), a temperature sensor like a TMP 35, some buttons, switches and potentiometers (10K and 100K), and some LEDs to help you learn the basics. Your power source will come later, after you determine what kind of microprocessor you will ultimately use.

I have left off the 'step counting' hardware. You might want to use tilt switches, muscular activity sensors or an accelerometer. Research this, and find out what works best.

Also get a few 330, 1000, 4700, 10000 ohm resistors. Power your Arduino from the USB cable to your computer. The same one you will upload your code over.

These parts should get you started toward your goal, and you might have some fun along the way!

No, I did not imagine it would be a beginner project. That's why I am playing around with the SenseHat. To get a feel for things and I am sure it represents baby steps. Also because I bought it a couple years ago for my kid to work with. Which he isn't, so his loss, it's my toy now. It does seem to have all capabilities I want, just easier to program and bulkier.
But now, I know a few things to research when I can not sit down to write lines of code, and what devices to buy and play with for a bit.
I doubt it will take me too long to learn what I need. The stuff I've been learning through Python seems second nature. Maybe because of its a lot like giving instructions to a kid.
Thank you for answering and advice.

That you know Python already is a great help. Of course C++ is a quite different language, the underlying concepts are very similar, so it'll be easy enough for you to grasp.

Then start simple. Maybe with the clock and display, try to get the clock to show on the display. Add the buttons. Then add sensors one by one.

One of the hardest parts is the memory. There's the built-in EEPROM but you can't just write to that all the time or it will fail soon. So you have to find a way to minimise the writes, while keeping track of everything.

Thanks for answering.

It still sounds pretty easy. As with Python, its a matter of remembering the commands/codes, grammar (if that's what it is called when using the right punctuation, lines, and indents), and assembling everything in the right order to make it work. When it comes to applying new knowledge use them in "baby step" projects. It also helps to find a good online community for when Google fails.

Can you tell that I am learning this independently?

Hopefully, no one thinks I am going to jump straight into the deep end. When I finish with playing around with the SenseHat's sensors, I do not want to be stuck because I do not know which direction to proceed and what stuff I should be buying. Plus, taking deviating in my studies helps me learn new things, find inspiration and better ways to achieve my end goal.
There is even a chance that if I make everyone's suggestions into a shopping list my son might become interested in electronics again.

MrsGatamon:
Hopefully, no one thinks I am going to jump straight into the deep end.

Well, that actually worked quite well for me, but I have been tinkering with electronics on and off for a long time.

So it's up to you how to start, whatever works.

I love your response. It assures me I am in the right place.
Also, I will stop defending myself.
Not that I do have a lot of experience. Mostly from a purchased beginner book on Python programming for the Raspberry Pi, and free programming lessons for the SenseHat.
But as stated, I am finding everything logical. I even looked at some sample code for Arduino Mini and many lines are familiar.
I was not lying about starting little. I have an autistic kid that often prevents me from doing anything other than stare at a screen, which is where my desire to research comes from. Also, because caring for him keeps me unemployed I have little money to spend so knowing what I will need is very important.
My ultimate goal with the Arduino is to create a type of wearable exercise aid I can sell. My original idea was much more ambitious, but I simplified it because of the limitation of available electronics and my own skills.
If I can not legally sell my end product because of Arduino components, I will just use the skills I learned to move on to another source of electronics. If there is no way to meet my end goal, the mental exercise will remain totally worth the effort.
Do not expect frequent posts from me because this is a project that will take time. 6 to 12 months if my older kid does not use my components for his own curiosities.

Any other inquiries will remain in their appropriate forum section.

Thankyou everyone for your aid and advice.

MrsGatamon:
My ultimate goal with the Arduino is to create a type of wearable exercise aid I can sell.

That's one of the most crowded markets you can think of. Going to be really hard to make something compelling enough to sell. It's going to be about functionality, size, case design, branding, packaging, distribution, etc.

If I can not legally sell my end product because of Arduino components,

There are restrictions on the use of the Arduino branding of course. Otherwise, none.

The Arduino brand is a product in itself, the components of which you can freely reuse in your own project. You're not going to put an Arduino (or even a clone) in anything wearable, you'll be designing your own PCB for that. You leave out all the bulk that makes up an Arduino, leave out all the components you don't need, add the things you do, etc. The Arduino boards are for prototyping and tinkering, and may end up in one-off projects.

I am still researching the legality of it all. It can be done if Arduino allows.
If anything I can start selling my finished product as a handcrafted item and prove they are paying for my time, creativity, and cost of supplies while giving credit to Arduino for the board or branded products. That is how I get away with selling stuff from my toy customizing hobby. I need to be careful that no credit for the branded item goes to me. I also need to respect the branded product, their intellectual property, company goals/values, and any legal request they make.
I still have plenty of time, after all, for researching. You forgot to mention testing, redesign, debugging, rinse and repeat. That should take me and some volunteers 6 or more months.

The market is definitely flooded, with hardly a new idea. There is more to my idea that I am keeping secret because I do not want it stolen and I tend to curse my projects by announcing ideas before they are finalized. The wearable art idea I freely share because it's too cool to keep under wraps with what everyone is doing with Arduino.

Wearables are usually designed to run on batteries and battery life is key. While Arduino boards are often used with batteries, they're not at all optimised for low power use. That's another reason why you have to go and design your own PCB. Huge power savings to be made (probably in the tune of 80-90%, especially if your project can be transferred onto an ATtiny).

I can imagine building boards will also solve a memory problem. My original idea (which I would like to return to someday if I am successful) required data to be saved and transferable. I did not want to rely on a phone app because a phone is not welcome in all settings. Transfers require data, networks, or cords. Which I view as a disadvantage. But I am aware that there are devices that can transfer and save data any way the user feels comfortable. From what I can tell, that is not quite possible with the Arduino.

As a note, pretty much whatever you learn by using a power hungry, wall powered device will be education.
once you have the bits working to your liking, you will naturally start to optimize, and when you are ready, we will be here to point you in whatever direction you want.

as an example, sensing of gasses like alchol, indoor air polutants, is often done by a sensor that uses a lot of power, needs 24 volts, heats up overnight, stays hot as long as you have power. cost a few dollars.
but, a MEMS ( Mcicro-Electrical-Mechanical) sensor that is the size of the end of a pencil is about $20-$35 and will run on batteries for months on-end.

start with what you can afford, figure it out, make it work, learn
adapt, adjust. when you are ready, take the next step.

So far, you have shown logic in your thinking, so really, it seems you are on a path, taken in steps that work, you will reach your goal.

MrsGatamon:
But I am aware that there are devices that can transfer and save data any way the user feels comfortable. From what I can tell, that is not quite possible with the Arduino.

Arduinos can do just about anything with the correct external hardware.
Out of the box an Arduino only has wired communication available. Use an ESP8266 based board (WeMOS Mini would be a good one for you, it's really small) if you want WiFi. Add an HC-05 or HC-06 for Bluetooth. That covers the two main wireless modes of mobile phones, and actually Bluetooth would be the preferred one as you don't need to mess with networking and so.
Same for many, many other wired and wireless protocols. All you have to do is add the correct parts, and that's no doubt just what those other devices did. After that of course you have to add the appropriate software divers, but if you design your software from the ground up with this in mind you can add and remove such communications very easily.

“ARDUINO” is really more of a platform than a device.
based around the bootloader, the Arduino platform is pretty much any chip that can be programmed with the Arduino IDE.

the ESP8266 that does wifi and now the ESP32 that does bluetoooth are examples of Arduino’s that fit the mold, but not the official list. as is the small ATTINY and the fast Teensy… list goes on an on…

if you need smaller, faster, more I/O of any type, it may be necessary to move away from the Arduino environment, but since programming in C++ can be moved to other devices easily, moving is not necessarily painful.

I have to agree with wvmarle that with the proper hardware… however, one place we do not try to go is video.

I am really liking the idea of building my own board. Not because of the legality issue, but as a way to make it the shape I need. The right shape will fit better inside the case I need to design, especially if I continue with the idea of wearable. art.

The major steps I need to follow now are

  • Finish up with my SenseHat project where I integrate its sensors into a program.
    Play around with an Arduino Uno by making little programs that utilize the sensors I need.
    Move on to an Arduino Nano to make the first wearable device, and wear the device myself to test things out to perfect my design. Tinker, debug, and redesign as needed.
    If I make it this far, start building my own boards. Pass a few of this prototype generation to a few chosen volunteers. With their input tinker, debug, and redesign as needed.

[li[/li]

During these steps continue necessary and random research, practice decorative soldering to gain experience, and leave my unattached components easily "borrowed" so the kid can learn electronic if he wants.

Awesome![/list]

It's also quite amazing how compact boards can be. Especially if you use the smaller packages for the processor and so. When you start putting components on both sides of the PCB it gets even smaller, but then you'll run into lots of practical problems.

MrsGatamon:
I doubt it will take me too long to learn what I need. The stuff I've been learning through Python seems second nature. Maybe because of its a lot like giving instructions to a kid.

i just had to remark on this, it's a good insight !
infact, a lot of stay-at-home moms could do worse than to spend their free-time on Maker projects - there's nothing that says women have to go the Mrth Stwrt way ! :smiley:
plus it could inspire more girls to tinker with electronics and programming as well.

i wish you well on your venture into this wondrous world.

BabyGeezer:
there's nothing that says women have to go the Mrth Stwrt way ! :smiley:
plus it could inspire more girls to tinker with electronics and programming as well.

" practice decorative soldering "
I love this thread !

we do hope this works out better than you planned !