PIC16f877, PIC18f2550, PIC18f42

Discussion in 'Embedded Systems and Microcontrollers' started by StatEP, May 15, 2007.

  1. StatEP

    Thread Starter New Member

    May 3, 2007
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    0
    hey everyone.

    i want to connect a PIC to a data Logger.
    i have PICdem 2+ demo board. app: mplab ICD2

    my data Logger has a USB serial Output. model no. DI-710U http://www.dataq.com/products/hardware/di710.htm
    i have a Connector for it.

    have any ideas how to connect it?
     
  2. beenthere

    Retired Moderator

    Apr 20, 2004
    15,815
    282
    You will have to be able to know the control codes for the DI-710 in order to set it up to operate, and have a lot of memory available to soak up the transmitted data. The details for running the 710 may be proprietary information.

    Datak has a freeware app available to run on any computer under Windows. You only get four channels and limited sampling rates, though.
     
  3. StatEP

    Thread Starter New Member

    May 3, 2007
    5
    0
    Datak i googled it. i can't find it.

    suggestion : how do connect the PIC to data LOgger.

    the hardware: Data Logger DI-710U only has Serial USB output.
    Yes i'm currently programming on setting the digital outputs.
     
  4. n9352527

    AAC Fanatic!

    Oct 14, 2005
    1,198
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    There's only a very slim chance of you being able to connect to the data logger through its USB port from a PIC. By design, all PIC USB interfaces are device/function endpoints and are not hosts. To connect to a USB device (such as your data logger) you'd need a USB host/controller.

    There is an easy way, if your data logger supports OTG spec. Atmel and Philips make OTG microcontrollers which you can use. However, there's no mention of OTG on the logger datasheet.

    I have no idea whether the Atmel device can function as a host only, you have to find it out by yourself. Philips OTG controller can function as a host only, I think this is a better bet. However, Philips devices are difficult to find, you have to search around. I forget the part number, but it started with ISP (IIRC).

    Another way is to get a stand-alone USB controller and then interface it to the microcontroller, probably gonna be a lot of hassle and needed a lot of time to finish. You most probably need to code the host driver protocol as well. Also, you could consider a small FPGA with USB host core. You could find the host core codes on OpenCores (even more hassle and need more time than a stand-alone host controller).

    You could also consider using the ethernet interface, if your logger has one. There are many ethernet interfaces for PIC micro.

    Last, you could tap-off the SD interface and read the signals to the PIC. Unless you are sure the timings are achievable then this wouldn't work. Slower MMC is a lot easier to work with, but yours probably has the higher speed SD and not the MMC. It's probably possible to force it to use MMC protocol, try inserting an MMC card and see if it works.

    I'm afraid there's no easy way to do what you are asking.
     
  5. StatEP

    Thread Starter New Member

    May 3, 2007
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    0
    Dear n9352527,
    Thanks for the informative post. i visited beyondlogic they used PDIUSBD11.
    it's a rare chip. is there any similar chip that does the same function.

    Best Regards,
    Alexander
     
  6. n9352527

    AAC Fanatic!

    Oct 14, 2005
    1,198
    4
    I don't think the PDIUSBD11 can work as a host controller. I was thinking of ISP1161 from Philips. Note that it is difficult to find. What you want is a host controller, and not function or device or peripheral controller.

    Host controllers are not easy to find, almost no one use them apart from big companies designing motherboards. Devices that talk to USB peripherals can also use them, but nowadays they use OTG controllers instead.
     
  7. beenthere

    Retired Moderator

    Apr 20, 2004
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    You couldn't find it because I misspelled it - it's Dataq. They make the DI-720.
     
  8. StatEP

    Thread Starter New Member

    May 3, 2007
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    however in http://www.beyondlogic.org/usbnutshell/usb7.htm

    they use PIC and PDIUSBD11. they're able to sync those together
     
  9. n9352527

    AAC Fanatic!

    Oct 14, 2005
    1,198
    4
    The problem is not in controlling or connecting the PDIUSBD11 with a PIC. The problem is that your data logger is a USB device and to connect to a USB device, you need a USB host controller. These are not equal, in a USB link, one end has to be a host and the other end has to be a device controller, except in OTG standard where they can negotiate the temporary host role.

    PDIUSBD11 is a USB device controller, while ISP1161 is a USB host controller.
     
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