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Multiple Acceleromenter sensors vb.net — Parallax Forums

Multiple Acceleromenter sensors vb.net

TucanTucan Posts: 3
edited 2014-06-05 22:31 in Accessories
Hi people!

First post! wooo! *cheers*

I have a few questions to the community. I have a project that requires around 10 accelerometer sensors and then report the data to a database table. I was looking at xbee's and arduino's and to be honest I am a little lost. I dont mind if 10 andruino's are connected to what I would assume would have to be a few different computers if that's what it takes, and I don't know much about xbee's. I went to the store and got an arduino uno and a parallax MMAA7455 3 axis accelerometer just to putts around with...

...and thats about where my knowledge ends.

So from my understanding 1 uno will support 1 accelerometer. So I would need 10 accelerometers and 10 uno's? Would I need 10 base xbee stations and 10 transmitters or can I use 10 transmitters and 1 receiver? I only ask about xbee's cause it would be nice if the accelerometer sensors were separate from the computer uploading the data to the database.

I plan to gather all the information onto a computer running a vb.net program and then upload it to mysql (unless you have a better idea that is).

Thanks for all your help and knowledge guys!

Sorry for so many questions, I am so anxious to play around with this stuff, just need a good kick in the right direction.

Comments

  • Mike GMike G Posts: 2,702
    edited 2014-05-31 05:26
    Welcome to the forum Tucan.

    Boy, you have a lot going on in post 1. First let me suggest a change to the microcontroller. Check out the Parallax Propeller as I know the Prop can handle 10 SPI/I2C devices which is what you have in the MMA7455, Honestly, I'm not sure how many the Arduino can handle. Anyway, that will yield one PC and one microcontroller.

    Add a Quick Start or WIZ820io for an internet connection. Now you can update MySQL over a network with or without a host PC. Note: the Quick Start uses a several pins and might not leave enough for controlling 10 MMA7455s.

    Propeller MMA7455 source code can be found on the OBEX or MMA7455 product page. Ethernet libraries and information can be found in the Spinneret forum.
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-05-31 07:21
    Mike, Did you mean to say "Add a Quickstart and a Wiznet"? The link for the QS is to the Wiznet.
  • GenetixGenetix Posts: 1,754
    edited 2014-05-31 11:26
    Are the accelerometers in one place or scattered around?
    I don't know about the Arduino but the Propeller can write data to an SD-Card for retrieval later.
  • TucanTucan Posts: 3
    edited 2014-05-31 12:45
    Thank you for the very thoughtful reply's, it was late last night and I just had a bunch of questions :)

    First, is the Propeller Activity board the board that you are suggesting? That is the only "propeller" board that I can find in stores around me.

    Second, the quickstart or wiz are ethernet based. The set of 10 accelerometers will be moving on objects around in a warehouse type location, so stringing 10 ethernet wires around to moving objects is not exactly my idea of fun, but I get what you are saying about the controllers. I have seen some bluetooth and wifi ones as well I believe, which is why I brought up Xbee's. If the only problem with the ethernet controller is that you would cover up 1 of the pins making it only be able to do 9 accelerometers, that would be fine too, I could make it work, 10 was just thrown out as a "higher then 7, less then 15" number. You are saying though, that with a propeller, ethernet card and accelerometer I could just update straight to mysql without a computer? Now I am very curious.... is this possible with a wifi connection too?


    Genetix: The accelerometers will be grouped together but moving around an indoor area. This will need to be in real'ish time so storing to an SD-Card for retrial later is not practical for my application.
  • TtailspinTtailspin Posts: 1,326
    edited 2014-05-31 21:02
    Tucan, where are you located?
  • NWCCTVNWCCTV Posts: 3,629
    edited 2014-05-31 21:28
    http://www.ebay.com/itm/10PCS-Arduino-NRF24L01-Wireless-Transceiver-Module-/251062580786?_trksid=p4340.m185&_trkparms=algo%3DSIC.NPJS%26its%3DI%26itu%3DUA%26otn%3D5%26pmod%3D250904838349%26ps%3D63%26clkid%3D780538492781172657

    I'm not sure how many of these could be used in one location, but the cost would be a lot less than a bunch of XBees. @Duane Degn has used and posted a lot about them on his index page: http://forums.parallax.com/showthread.php/135706-Index-Test Post # 1 towards the bottom.
  • Beau SchwabeBeau Schwabe Posts: 6,566
    edited 2014-05-31 22:08
    Just curious, are any of the accelerometers mechanically "locked" to the same plane? The reason I ask is because there are some interesting things that happen when two or more accelerometers are locked to the same physical plane and you can mathematically drop any common mode noise.
  • GenetixGenetix Posts: 1,754
    edited 2014-06-01 00:49
    A warehouse is a very noisy environment, electrically, and it can be a harsh environment for electronics.
    What exactly are you trying to measure and how often?
    If your taking occasional measurements then a Propeller should no problem transmitting that data to some kind of receiver.
    I've seen WiFi used in warehouses but usually computers and workstations are wired to the network.
    Parallax makes a clear plastic enclosure that some Propeller boards fit in but I don't remember if the Prop BOE is one of them.

    Will the accelerometers be on forklifts or attached to boxes or pallets?
    Are you trying to see what happens in the warehouse or what product experiences?
  • TucanTucan Posts: 3
    edited 2014-06-01 02:37
    Thank you all again for so many answers!

    Ttailspin - colorado

    NWCCTV - thank you for the link, I will have to check them out, 10$, cant go wrong, maybe for a different product though....

    Beau Schwabe - No, the accelerometers will all be on different planes, increasing the number per plane would be a crazy amount of accelerometers

    Genetix - You are close with the "or what product experiences" information, in real time as possible.

    Due to legal reasons I am not able to discuss "in detail" about the product but its about 10 accelerometers, connected to a product moving around a warehouse and needs to upload the data to a mysql type database situation. After digging around today I found the Activity Board, which to my understanding I can connect to the 10 accelerometers, then the Activity Board has a slot for a xbee, I can just plug the xbee and send all 10 accelerometer readings back to another xbee with a xbee explorer usb connected to it... I think.

    Correct me if I am wrong on any of this, I am new to all of this and want to make sure I get all the correct parts I need as there are so many different types of boards and chips and fun stuff.

    Thanks again for all the help!
  • TtailspinTtailspin Posts: 1,326
    edited 2014-06-01 07:33
    If you would like, PM your shipping address to me, and I will send you a P8X32A QuickStart (rev A) board that you can experiment with.
    Brand new in a box, with USB cable and everything, well, everything except a 4 to 9 volt power supply.


    -Tommy
  • GenetixGenetix Posts: 1,754
    edited 2014-06-01 22:09
    I think the limiting factor will not be the Propeller collecting data but transmitting it a PC.
    If the PC is in one corner and your product in the other then there is a lot of metal in between that will block or greatly reduce your signal.
  • TtailspinTtailspin Posts: 1,326
    edited 2014-06-05 22:31
    Tucan,
    I like to use this product (Proto Board) It has lots of room to solder things, and it allows for 700mA from the onboard Voltage regulators.
    All thirty two pins are available for any task, and the eight processors(Cogs) are just what is needed for multitasking a bunch of sensor inputs.

    The QuickStart and the Proto Board are identical in that they both use the Prop (P8X32A), It is the accessories that make the difference.
    QuickStart has touch buttons built onto the PCB, and doesn't supply the same horsepower from the voltage regulator. It's fun to play with.
    But the Proto Board is the way to go if you are handy with a soldering iron, Be sure to check out the Project Board too, it has USB built in,
    and you would not need to buy the Prop Plug, so you save a couple of bucks.

    Just to be clear in answering your question, Either board will run many more devices than one at a time,
    It is possible(and has been done) to run 32 servo motors at once. and with I2C the sky is the limit...

    We should carry this on in the forum, so more than myself can offer you help, and others can benefit from the answers. :)
    I will just cut and paste this response straight into your original thread.

    Feel free to ask any questions you might have, especially about your project, it sounds interesting, and the people around here like interesting...:smile:


    -Tommy
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