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TDC1000-C2000EVM: Application using TDC1000 for measuring water level in tanks

JFrankVC-ECN
Prodigy 10 points
Part Number: TDC1000-C2000EVM
Other Parts Discussed in Thread: TDC1000, PGA460

Hi everyone,

I've been testing the TDC1000-C2000EVM and I wanted to know whether the TDC1000-C2000EVM is adapted for this application: measuring water level from top in tanks having a height between 4 and 8 mts.

In the TDC1000 datasheet, the application of measuring water level is done from bottom (the ultrasonic sensor is at the bottom), but I wanted to know if the same ultrasonic sensor from STEMiNC could be used to do the measure from top instead of doing it from bottom.

Besides that, in the forum I found some interesting answers related to my application, but I still have some questions. For example, the GUI I downloaded for the TDC1000-C2000EVM doesn't has the option in the Setup tab to change the Clock source to that of the CPU so I can drive 40kHz ultrasonic transducer. I know the water level measure is done with a 1MHz ultrasonic transducer, but for the moment I have just access to 40kHz transducers and I would like to test them and see some results. Do I have to download another GUI or how can I change the Clock source of the TDC1000-C2000EVM to a source different from that of the board?

I found the evaluation board very interesting and I would like to know:

Is this evaluation board suitable for the application? Are there any other evaluation boards suitable for the application if TDC1000-C2000EVM is not?

I am starting learning and working, about and with, respectively, ultrasonic transducers. I knew there are Senders and Trasnmitters and I just discover there are Trasnceivers (Tx and Rx in one packet). With the TDC1000-C2000EVM, I found a schematic showing the transducer connected (Positive pin) to both Tx1 and Rx2 (Mode 0) and the other to GND, is it correct? Does the TDC1000 fits for an application including a Sender and a Receiver separately, or it must necessarily be a Trasnceiver?

Thanks.

José Villanueva

  • 0
    TI__Mastermind 31655 points
    Hi Jose,

    I will answer your TDC1000-C2000EVM questions first. Unfortunately the only options for the clock source to the TDC1000 on the TDC1000-C2000EVM are the onboard 8Mhz clock, or an external clock. There is no provision to use a clock generated by the C2000. You can adjust the transducer excitation frequency via the TX_FREQ_DIV register in the GUI, but none of the available options will get you exactly to 40khz. There is an unpopulated connector on the board that is intended for use with an external clock (EXT_CLK J9). That is where you would connect your clock signal.

    For such a large distance of 4-8 meters in air I do not believe the TDC1000 fits the application. The maximum record length for the TDC1000 is 8ms, which in air (speed of sound 343m/s) means it can measure up to about 1.3meters. Even if you measured from the bottom through water (speed of sound 1400 m/s) the maximum distance would be about 5.6 meters. This is not to mention the difficulty with attenuation through air. For this application the PGA460 would be a better option.

    All piezoelectric transducers are both transmitters and receivers. The TDC1000 is configured to use a single transducer for both transmit and receive, as well as using separate transducers if that is desired.

    Regards,