• State Resolved
  • Locked Locked
  • Replies 6 replies
  • Subscribers 30 subscribers
  • Views 1322 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

Original question:

TDC1000-TDC7200EVM: Proper usage of Evaluation Board

TDC1000-TDC7200EVM: TDC1000-TDC7200 EVM Evaluation Board

Sachin Davis
Prodigy 90 points
Other Parts Discussed in Thread: TDC1000, PGA460, TDC7200

I tried everything mentioned in the documentation but I might be doing something wrong here but I can't get any output when I use a transmitter and receiver. When I use a single sensor as a transmitter/receiver I get an output but I cant really confirm if its just noise or an actual data. 

I can't manage to find the pin-out of the J5 connectors in the board. Anyone have an idea.

Thanks in advance......

  • 0
    Prodigy 90 points

    Sachin Davis said:

    Part Number: TDC1000-TDC7200EVM

    I tried everything mentioned in the documentation but I might be doing something wrong here but I can't get any output when I use a transmitter and receiver. When I use a single sensor as a transmitter/receiver I get an output but I cant really confirm if its just noise or an actual data. 

    I can't manage to find the pin-out of the J5 connectors in the board. Anyone have an idea.

    Thanks in advance......

    I am trying to (as a test) measure the time of flight of a surface (table) and how it changes when I introduce a disturbance ( test object).

  • 0 in reply to Sachin Davis
    TI__Mastermind 31655 points
    Hi Sachin,

    Are you measuring through air with the transducer supplied with the EVM? It is a 1Mhz transducer that is best suited for liquid measurements. The 1Mhz signal will attenuate much too quickly through air, and it is very unlikely that you will see a return echo.

    Transducers in the range of 40khz-300kHz are better suited for gas measurements depending on the distances required. Please see the TDC1000-GASEVM for an example of the TDC1000 used with gas-coupled measurement.

    Additionally, if your application is purely for distance measurement through air, the PGA460 may be a better option, as it is designed specifically with air-coupled time of flight measurements in mind.

    Regards,
  • 0 in reply to Scott Cummins
    Prodigy 90 points

    Hi Scott,

    Thank you again for taking time to reply. Yes, I have been using a 1 MHz ultrasound sensor. However I am not using the sensor that came with the device but I am using a Liquid Flow Sensor (SMFM21F10000SS) from STEMINC shown below. I have been testing the sensor in air to understand its working. As a test I placed the sensor fixed in air and I moved a test object towards/away from the sensor. I did not get what I expected. I expected the TOF to decrease/increase with the relative distance of object from sensor. Is it because I tested this in Air.

    My goal of using the sensor is to identify defects/irregularities in a pipe which has a flow of water through it. The specifications of the sensor are as follows: 

    Part Number: SMFM21F1000SS, Dimensions: 12.95mm x 7mm, Rated Noise Power: 5.5Vp-p, Rated Long Max.Power: 30Vp-p, Resonant frequency fr: 1Mz±2%, Static capacitance Cs: 584pF±20%@ Impedance: ≤210 Ω, Sound Pressure: 90 dB, Operation Condition: -10°C-+60, Applications: Liquid flow sensor for pressures up to 150 Psi.

    1) Please let me know if this the right choice of sensor for my application.  

    2) I also haven't understood exactly how the Evaluation board calculates the Time of Flight. If you can send me over some documentation for the same it would be useful.                                                                                                                                                                                                                                               

    3) Also a document that explains the various parameters in the application would be useful.                                                                                                               

    4) How does the J2 connector work. It is a 14 pin channel out of which pins 8 - 14 are TX2,RX1,TX1,RX2 etc.... But what are the pins 1 - 7. Are they all connected to ground ?

    5) When I use 2 sensors and switch to Mode 1, I obtain no output the TOF indication and the graph does not respond. It stays as it is. What could be the reason to this problem?

    All help appreciated.

    Thank you,

    Sachin.

  • 0 in reply to Scott Cummins
    Prodigy 90 points

    I still have a few more doubts. Please look into the reply above.

    Thank you,

  • 0 in reply to Sachin Davis
    TI__Mastermind 31655 points
    1. This transducer will work well for measuring time of flight through a fluid. It will not work very well measuring through air. As I mentioned in my previous post, you are very unlikely to get a usable signal in air with this frequency and type of transducer.

    2. The time of flight is measured by either the TDC7200 or the MSP430 on the EVM depending on the settings you have selected. The TDC1000 datasheet explains how it determines when to output signals that are used to measure the time of flight, and the TDC7200 datasheet describes how it measures the time of flight.

    A complete list of documentation is included in the FAQ along with answers to common questions: e2e.ti.com/.../3611.everything-you-need-to-know-for-ultrasonic-tof-liquid-coupled-collateral-tools-designs-faq

    3. See above.

    4. The top row of pins on J5 are labeled on the board. The bottom row are all ground. Please see the TDC1000-TDC7200EVM user's guide here: www.ti.com/.../sniu021a.pdf

    5. As described above, the sensors are not designed to work well in air. Test these with water after having reviewed the documentation described above.
  • 0 in reply to Scott Cummins
    Prodigy 90 points
    Thank you Scott...Will contact you if I have any more doubts