• State Resolved
  • Locked Locked
  • Replies 3 replies
  • Subscribers 30 subscribers
  • Views 1010 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

MSP430 + LDC1000 ==> RS485 sensor network

stephen freyder
Prodigy 20 points
Other Parts Discussed in Thread: LDC1612, LDC1614, LDC1101, TM4C1292NCPDT, MSP430F5528

I'm looking to build a sensor array using multiple MSP430's connected via SPI to multiple LDC1000's.  These will be interconnected via some kind of high-speed communication like RS485 to forward selected data to a master controller which will assemble it into TCP packets on an ethernet connection to another machine which will perform the analysis.

I have ordered some MSP430F5529LP launchpads, and I have 5 LDC1000QEVM's which I plan to break apart and connect to the launchpad(s), have installed CCS and GCC, and the updates.

So I'm looking to see what software resources TI has to get me going - something for SPI access to configure and acquire data from the LDC1000's, and hopefully some kind of master/slave RS485 communications functionality to relay the data from the MSP430's to the ethernet concentrator (which will be another TI processor).

Also, is there a way to have a phone conversation with an FAE?  I don't know what is usual and customary nowadays, 25 years ago it was standard to have an FAE assigned when we started a new project like this - is it still done that way?

Thank you.

Steve Freyder
Systems Engineer

Transcore

Plano, TX.

  • 0
    TI__Genius 13650 points
    Hi Stephen,
    the firmware source code is automatically installed with the GUI. This will be installed in a directory similar to: C:\ti\Sensing Solutions EVM GUI-1.8.8\EVM Firmware\FDC2x14_LDC13xxRevB_LDC16xxRevB_EVM_Firmware_source

    I reached out to the field team and requested to get in touch with you.

    By the way, what are your sample rate requirements?
    Would the LDC1612Q meet your needs? The high-resolution multi-channel LDCs (LDC1612, LDC1614) are L-only devices which offer greatly improved measurement accuracy, better part-to-part variation, lower power consumption, easier design integration, and multiple channels.

    Do you need the Q-grade part?
    If not, then I recommend considering the LDC1101. The high-resolution, high-speed LDC1101 supports both L- and RP-measurements,  greatly improved measurement accuracy, better part-to-part variation, lower power consumption, and easier design integration.
  • 0 in reply to Ben Kasemsadeh
    Prodigy 20 points
    Hi Ben,

    Thanks for the quick response. I'm going to have to consult with some of our other engineers on the need for Rp, but I think the 1614-Q1 looks ideal. I see these are using I2C instead of SPI. Using the MSP430 (say the 5528/5529 class parts) what kind of upper limits on sampling rate would TI recommend could be supported? We're looking to hang these 430's off some kind of high-speed serial (RS-485 probably) bus so we need to be able to take this data and put it on that bus. My ideal solution would be a generic byte-stream interface relaying the samples from the 1614Q's across this bus to a TM4C1292NCPDT (so far that is the choice) where it would be TCP-encapsulated along with the data from the other MSP430's/1614Q's and sent to our host for analysis. We may need to have some amount of filtering in the MSP430's to reduce the load on the serial bus. I am hoping that TI has some software already existing that would manage the basic RS-485 communication (multi-master packet oriented transmission, or polled master/slave) in both the 430's, and in the 1292.

    The application here is an in-ground pressure sensor with one "pressure point" (coil+LDCxxxx channel) about every three inches with an overall length of 8-10 feet.
  • 0 in reply to stephen freyder
    TI__Genius 13650 points
    Hello Stephen,
    the high resolution LDC161x-Q has a maximum sample rate of 4.08ksps (single channel). The mid resolution LDC131x-Q has a maximum sample rate of 13.3ksps (single channel). Both rates are limited by the I2C transfer speed (SCL = 400kHz).

    Our current firmware supports streaming at up to approximately 1ksps. We provide the source code for this firmware for the MSP430F5528 to use as an example (automatically installed into your GUI directory).

    Firmware could be written to support higher speeds of the device limitations above, but we currently don't offer firmware examples for this. As far as I know, the MSP430F552x MCU is not available as with automotive qualification, but other MSP430 MCUs are. Please check on the MSP430 forum for selection of a suitable automotive qual MCU.