Which Arduino To Use?

Projects General Guidance
1

I am pretty inexperienced with electronics. I have an Arduino UNO that I have successfully set up, programmed, and am using with a computer project, and am moving on to another project, so I need another one.

However, there are so many models and variants of the Arduino now that I am unsure which one to select.

My project is pretty simple:

  1. There will be 8 LEDs connected to the Arduino, each to a separate output pin. The running sketch will read COM input from a computer, and based on the data it receives, it will vary the state of the 8 LEDs. The LEDs are 2v to 3.5v, 20ma to 25ma each. It is possible that all will be on at the same time, so that's a potential 200ma total load.

  2. The Arduino will need to be able to sense the state of up to 6 mechanical switches (some are momentary and others are not) and the running sketch will execute the appropriate code, such as turn on a pin or send a message back to the computer via the COM connection.

Based on this, which Arduino should I select?

Thank you.

2

The choice usually comes down to how small you want to make your project. If you can fit the Uno then use that. Nano, Micro, Mini and Teensy all have different smallness.

For that many wires, the smallest ones will be unsuitable, but remember you can use all the analog pins as digital inputs and outputs.

Then the next size limitation is memory. Something that is heavy with user interface code, like if it has a screen, will easily exceed the memory capacity of the Uno, Mini and Micro.

3

Thanks. The UNO's 32KB of memory will probably be more than sufficient.

A larger size Arduino isn't much of a concern.

So based on this and what you are saying then a UNO will still work for my project.

Since it's likely that I could make a mistake and damage the Arduino, I'm considering this board:

It is ruggedized Arduino variant.

The only thing that I see that gives me pause is that it shows that "Total microcontroller current protection" is 150ma. In their demo video on their home page, "5 more ways to destroy an Arduino" it talks about 200ma is the limit for the UNO. Why would theirs protect up to only 150ma? I don't understand the discrepancy.

4

MossyRock:
So based on this and what you are saying then a UNO will still work for my project.

Indeed it will.

The only thing that I see that gives me pause

I would have thought the price might too. The Ruggeduino has the same guts and therefore the same power handling ability as any other Arduino. With a 200ma limit, protecting to 150ma sounds reasonable. Essentially, and as the blurb implies, it is made for idiots who don't know what they are doing or, more particularly, rich idiots who don't know what they are doing. Since it costs ten times more than a standard Uno, you might find that, if you have a crisis of confidence, or are inclined not to read instructions, you could be better off buying two ordinary Unos, and keep the second in the bottom drawer.

You will probably find a use for it later.

5

Nick_Pyner:
The Ruggeduino has the same guts and therefore the same power handling ability as any other Arduino. With a 200ma limit, protecting to 150ma sounds reasonable. Essentially, and as the blurb implies, it is made for idiots who don't know what they are doing or, more particularly, rich idiots who don't know what they are doing.

I would more easily believe that it was made for lab use, where hundreds of students would be using or abusing it. I liked two features on it, the crystal clock and increased current on 3.3V.

The product page suggests the student use, engineers who want a more robust product (I would assume that the company is paying for it!) and "anyone who makes mistakes". I don't see the "rich idiots" implication in there. But you are entitled to your opinion. As a learning tool, the Arduino should be expected to encounter "idiots who don't know what they're doing". But I agree somewhat that replacement of a cheap board with another cheap board might be a more economical solution. Also the lesson learned from the failure might be valuable!

6

Thank you all for this information.

Points well taken about buying two standard UNOs for the price of one of these. It has some additional features that the UNO doesn't have. A $55 price point is not that bad.

Nick_Pyner:
With a 200ma limit, protecting to 150ma sounds reasonable.

Can you explain what the above means? It would make sense to me if the product would blow a fuse if the current flow exceeded 200ma, but this implies that it will blow a fuse at 150ma. That wouldn't give me enough capacity on this unit.

7

hello i am a beginner electronics and i have a school project to do. i'll appreciate any help.
i want to build a receipt printer that connects to a database .
based on my understanding the device will be at different restaurants to print customers order based on the restaurant chosen by the customer.

8

easyadin:
hello i am a beginner electronics and i have a school project to do. i'll appreciate any help.
i want to build a receipt printer that connects to a database .
based on my understanding the device will be at different restaurants to print customers order based on the restaurant chosen by the customer.

Easyadn, you need start a completely new topic/thread with your question.

9

MossyRock:
Points well taken about buying two standard UNOs for the price of one of these.

No, it's ten standard Unos, and the price point is absurd.

It would make sense to me if the product would blow a fuse if the current flow exceeded 200ma, but this implies that it will blow a fuse at 150ma. That wouldn't give me enough capacity on this unit.

If the absolute limit is 200ma, it isn't unreasonable to limit regular use to 150. I believe this is done with a current limiting IC. There are plenty of ways to power things a lot gruntier than a piffling handful of LEDs, people do it all the time, and you just need to learn a bit about how to do it. I imagine it involves no more than using current limiting resistors, which is standard practice.

10

Nick,

TEN standard UNOs? Where are you seeing that?

On their microcontroller boards page, the Ruggeduino shows it costing $54.95.

On the Arduino Store page, the UNO costs $24.95.

Screen snips attached.

Thanks for the explanation about the 150ma limiting and my piffling handful of LEDs! That makes sense.

Ruggeduino.JPG

Arduino_UNO.JPG

11
12

Read the ruggeduino product page. It doesn't use anything as brutal as a fuse.

Yes, for work purposes its much easier to get the boss's approval for one expensive unit rather than three cheap ones "in case I blow one up".

13

The UNO has just two principal applications - learning and prototyping (that is one), and an application for which a "shield" is available which fully implements the application.

For all other applications and end products, you want either a Nano if USB functionality is required, or a Pro Mini if it is not. These come with pins not fitted by default instead of the inconvenient sockets on the UNO, so you can solder connections to them or alternatively, use the pins provided to mount them as a "daughter board" to a custom PCB of your design.

Or indeed, you can use them with the pins fitted, in a solderless breadboard with vastly greater design flexibility than a UNO.

14

no one really spelled out the similarities

the UNO is based on a DIP chip and have 6 analog inputs.
the Nano and Mini use the SMT chip and the only difference is they offer 8 analog inputs.
other than that, the power, the memory etc, is the same.

the pro-mini [ edit : pro-MICRO ] uses an internal USB interface a'la the Leonardo and offers 12 analog inputs. but. you lose digital ones.
not really lose, they are an either/or option. a note here is that the analog on any unit can act like a digital.

the ruggeduino is an UNO with a kevlar jacket. 'most' simple mistakes in wiring are protected against.

there are a slew of tiny Arduinos, the Digispark, the Trinket, etc. all have small forms and reduced pin counts. [ and reduced memory ]

the EXSP8266 is the odd one. with only 1 analog and a handful of digital pins with varying requirements. strictly a 3.3 v device. this is odd, it does Wi-Fi but also has a few pins, lots of memory and is available in an UNO form factor to use shields. it plays so well with any Arduino, that it is both a replacement and accessory, depending on your needs.

There are a few variations of the Teensy, based on a a Cortex processor, it runs at a different clock speed, has lots more memory. 12 bit analog out, 16 bit analog in, depending if you can connect to pads, not pins, you can get lots more analog inputs. odd, VERY odd, pad placement makes it hard to use.

Once you open pandora's box of alternate CPU's, there is a vast array of options. too many to cover and changing so fast.. op's another was just released... that it would be impossible to keep up....

not mentioned in any posts so far is the Mega, not many clones for that. more memory and more pins

but there is a third board/chip in the ATMEL family, the 1284
http://www.crossroadsfencing.com/BobuinoRev17/
this uses nearly the same programming but offers more memory, more pins and fits nicely between the UNO and MEGA in the same form factor that allows use of shields. many of us feel that this should have been the root chip to start this whole revolution. not too big, not too small..... alas, Bob did not pick a great name. no professor wants to tell the students to pull out their bobweeny.....

I like to use the UNO for testing. using shields is just to easy.

I like the NANO because I use the screw terminal board for it.
http://www.ebay.com/itm/321999039619
this offers me options for my uses.

a note on the mini. there is no duplication. the pins or the extra analog are either over here, or over there, in line or stacked.... I2C pins are not bread board compatible, they are lined up between the normal pins. if you make a custom board, better order all the mini's before you order boards. every seller from China changes with each new lot of boards.
the Mini was originally based on the BasicStamp, the over priced, delicate student board that thrived until C pricing was brought under control and made simply by the Arduino. the pins are laid out to replicate the BasicStamp.

15

Paul__B:
The UNO has just two principal applications - learning and prototyping (that is one), and an application for which a "shield" is available which fully implements the application.

For all other applications and end products, you want either a Nano if USB functionality is required, or a Pro Mini if it is not. These come with pins not fitted by default instead of the inconvenient sockets on the UNO, so you can solder connections to them or alternatively, use the pins provided to mount them as a "daughter board" to a custom PCB of your design.

Or indeed, you can use them with the pins fitted, in a solderless breadboard with vastly greater design flexibility than a UNO.

I use the UNO and a SD card / RTC chip and some small circuits to do data logging. it is just too simple.
and there are enclosures you can use to house this assembly. that adds one thumbs up to the UNO/shield for field use.

16

dave-in-nj:
the pro-mini uses an internal USB interface a'la the Leonardo and offers 12 analog inputs.

Oopsie!

dave-in-nj:
I use the UNO and a SD card / RTC chip and some small circuits to do data logging. it is just too simple.

And that is just what I said. If there is a shield for the job, that works out neatly. If there is no shield, the Nano is better.

17

Paul__B:
the pro-mini uses an internal USB interface a'la the Leonardo and offers 12 analog inputs.
Oopsie!

pro-micro.... I said pro-micro, right ?