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Topic: Using a laptop in place of shields? (Read 2348 times) previous topic - next topic

golightlyj

I am curious if there is an interface available so that one could us a laptop in place of the different accessories for the communications end of things? I can pick up a cheap laptop for around $200 whereas it would cost at least that to get an LCD, a data logger, WiFi, cellular communication... I have done some searches and have not found anything.

 

MorganS

I usually buy the expensive shields from the full-service shops that actually design the hardware and give me a good library to use it. I would find it difficult to spend $200 to buy that list of parts.

Yes, you can do some of that with software on the PC. The cellular communication might be difficult though. You would need a PC that takes a SIM card. I think just that one thing will blow your budget.

For the other stuff (display, record data,  internet connection...) then that's exactly what this particular sub-forum is for. Do you have a specific problem that you would like help with?
"The problem is in the code you didn't post."

Nick_Pyner

#2
Jul 21, 2016, 07:16 am Last Edit: Jul 21, 2016, 07:18 am by Nick_Pyner
Spending "at least that to get an LCD, a data logger, WiFi, cellular communication" might actually  be pretty extravagant, and quite likely difficult.

Similarly, if you really are looking at paying $200 for a "cheap" laptop, you clearly haven't been trying hard enough, and the same applies if you haven't found anything in your searches. I submit $50 would be absolute top dollar for a cheap laptop to use with Arduino and that might be split as $35 for a kosher XP sticker and $15 for the laptop it is stuck to.

In the datalogging arena, Arduino may serve two broad purposes:

1. as a stand alone device, thereby needing comms, recording  and display peripherals in addition to the sensors, or

2.  simply as a convenient interface between the sensors and the PC, whereby the latter does all the real work.

There will be grey areas between the above in light of convenience, cost, practicality. and your computer skills, but both approaches are equally valid.

Riva

Why bother to use an Arduino if it's permanently connected to a Laptop?
Don't PM me for help as I will ignore it.

Robin2

The USB cable is the simplest (and very effective) interface between an Arduino and a PC.

I am a great believer in the value of cheap PCs in place of specialist peripherals and in the proper division of tasks between the PC and the Arduino.

A cheap used laptop running Puppy Linux will probably perform very well. Certainly much better than the same one using Windows XP. You can run PuppyLinux from a USB stick if you want to, and it is a good way to try it without screwing up the existing OS on the PC.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

Nick_Pyner

Why bother to use an Arduino if it's permanently connected to a Laptop?
Us lesser mortals find it convenient.

Riva

Us lesser mortals find it convenient.
But the OP says "I can pick up a cheap laptop for around $200 whereas it would cost at least that to get an LCD, a data logger, WiFi, cellular communication". Ignoring the costs discussed earlier in the thread it seem the Arduino is just an interface to some sort of sensor and the Laptop is the Power, logging storage, display & WiFi/Cellular.
Don't PM me for help as I will ignore it.

CrossRoads

Laptop display can be great for displaying stuff, like plotting out data the Arduino is capturing.
Or for pulling data into a spreadsheet and quickly manipulating/filtering/sorting, all stuff that could be awkward to do on an Arduino because of the small amount of SRAM, and having to write the spreadsheet code.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

Nick_Pyner

#8
Jul 21, 2016, 05:20 pm Last Edit: Jul 21, 2016, 05:22 pm by Nick_Pyner
it seem the Arduino is just an interface to some sort of sensor and the Laptop is the Power, logging storage, display & WiFi/Cellular.
That is exactly right. What with the gold stars you have under your name, I'm surprised you are having trouble understanding this. Perhaps reading reply #2 again might help. There is a rather long word in there, but you can break it down:    con-ven-i-ent

golightlyj

#9
Jul 22, 2016, 01:08 am Last Edit: Jul 22, 2016, 01:15 am by golightlyj
Why bother to use an Arduino if it's permanently connected to a Laptop?
The Arduino will be operating sensors and valves so I need it for the inputs and outputs. The computer would mostly serve as means of sending me texts when there are problems, data logging...

The USB cable is the simplest (and very effective) interface between an Arduino and a PC.

I am a great believer in the value of cheap PCs in place of specialist peripherals and in the proper division of tasks between the PC and the Arduino.

A cheap used laptop running Puppy Linux will probably perform very well. Certainly much better than the same one using Windows XP. You can run PuppyLinux from a USB stick if you want to, and it is a good way to try it without screwing up the existing OS on the PC.

...R
You are right on my train of thought Robin2. The problem with this is that I know squat about Linux. Maybe that is a good place for me to start?? Will Linux make it easy for and Arduino to communicate and send commands to a laptop? 

Nick_Pyner

#10
Jul 22, 2016, 02:57 am Last Edit: Jul 22, 2016, 03:50 am by Nick_Pyner
I submit that you would be simply leaving the mainstream for no good reason and going off in a futile exercise in friendless fields with Linux, and seriously, knowing squat about it is a really good idea. The grungiest XP laptop you can buy will have more power and resources than you will ever need with an Arduino and, if performance ever becomes a problem, it is probably time to keep the laptop and ditch the Arduino.

One thing I would like to point out, and further to Crossroads's perceptive comment: if you are picking through cheapo XP laptops, go for one with an old version of Microsoft Office, i.e. Office 2003 or earlier. This will enable you to use PLX (qv) to painlessly run Arduino data directly into Excel.

Trust me, XP laptop with ancient MS Office + PLX + Arduino is the data aquisition menage-a-trois made in heaven.

You may be fortunate enough to have an old MS Office already. Don't chuck it out.

On a completely different tack but towards the same mark is the cheapo Android phone. They offer their own assets and are even more convenient to use in the field.
Phone + Bluetooth Graphics Terminal + Arduino is another of those great combinations you will wonder how you ever lived without.

golightlyj

#11
Jul 22, 2016, 03:34 am Last Edit: Jul 22, 2016, 04:47 am by golightlyj
Thank you Nick. I now have a good place to start! I do have an old XP laptop floating around but as I recall, it has seen better days. There is a laptop repair/sales place up the street from me, I'll hit them up. I will have to do some research into this PLX that you speak of and get a laptop of some sort up and  running. I will keep this updated as progress.

Nick_Pyner

#12
Jul 22, 2016, 05:56 am Last Edit: Nov 06, 2018, 01:07 pm by Nick_Pyner
PLX-DAQ is a macro for old Excel. It effectively turns Excel into a terminal thereby enabling you to update spreadsheets live, including graphs, which means you number-crunch where the real numbers get crunched, and not on Arduino.

Some background is here
http://homepages.ihug.com.au/~npyner/Arduino/GUIDE_2PLX.pdf

You may find your XP laptop is entirely adequate. They have all seen better days. I believe the biggest problem with XP laptops is the hard drive. It is likely to be IDE and they are getting rare and unreasonably expensive. Needless to say laptop hard drives are the ones that fail before they are simply retired. The drive on my Dell 505 - cost $42.70 - eventually died, but this laptop is exclusively used for Arduino and the like, and it is now running XP on an 8Gb CF card liberated from a digital camera.  This is so easy and effective that I suspect an old IDE laptop might be a better proposition than a SATA!

I'm a true-blue Dell man and I know nothing about the others. If you are rummaging amongst Dells, note that.

The SD slot on XP-era Dells like my lovely 430, only works with the original XP. They never got it to work with XP service packs. Don't ask why, it seems that they simply gave up.

The Toshiba bluetooth stack facility is one of Dell's best assets.

The Pro-Sys Wifi is one of Dell's worst liabilities - unless you use an all-numeric password. It then becomes an asset(!)

Some Dells look like they have features, but don't. My D505 has everything except bluetooth, but you can see a bluetooth light in the hinge. Check the setup.

The desktop expansion unit works with all laptops of the era but will only work with its own high-power charger.




Riva

That is exactly right. What with the gold stars you have under your name, I'm surprised you are having trouble understanding this. Perhaps reading reply #2 again might help. There is a rather long word in there, but you can break it down:    con-ven-i-ent
So what exactly is your problem with me that you feel the need to hone your trolling skills on the posts I made here?
Don't PM me for help as I will ignore it.

Robin2

I submit that you would be simply leaving the mainstream for no good reason and going off in a futile exercise in friendless fields with Linux,
Well, I guess it's an opinion. But it is not shared by me or the many users of Linux.

I notice that you have not challenged my assertion that the laptop would perform better with Linux :)


Will Linux make it easy for and Arduino to communicate and send commands to a laptop? 
The Arduino won't know or care whether the PC has Linux or XP on it. The easiest one will be the one you are familiar with.

...R
Two or three hours spent thinking and reading documentation solves most programming problems.

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