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BOOSTXL-PGA460: no data from the data monitor

Genius 9880 points
Part Number: BOOSTXL-PGA460
Other Parts Discussed in Thread: PGA460, , MSP-EXP430F5529LP

Hi,

Customer having a problem with the device after changing the PGA460 IC, details below.

"I'm having a problem with my BOOSTXL-PGA460. i can't get any data from the data monitor. see attached. This is using  BOOSTXL-PGA460 + MSP-EXP430F5529LP + daughter card.

I've bought the boards in 2019 It used to work but then unfortunately i've damaged the PGA460. So i replace chip only and it works but i can get no data.

"

Regards,
Maynard

  • Hello Maynard,

    Just a couple of things to check initially:

    1) Can the customer check his settings for the amount of burst pulses being transmitted? Perhaps he has the number too low hence why they're not seeing the echo.

    2) Check that the transducer is connected to the daughter card properly. If there is no transducer plugged in then the device cannot output or receive ultrasonic signals.

    3) This one goes along with point 2, make sure that the correct transmit frequency of the device is equivalent to the resonant frequency of the transducer.

    4) If the customer is unsure if the device is transmitting properly, they can probe the output that connects to the transducer to observe if there is an output signal.

    Based on the graph it seems like the device could be transmitting properly but perhaps not at the right frequency or the target might not be present/too far, so another suggestion would be to hold a target at a close distance to see if they observe a return echo.

    I hope this helps the customer begin troubleshooting their error.

    Best,

    Isaac

  • Hi Isaac,

    Thank you for your response, below is the reply of the customer.

    1) I used the "Default All General Registers for muRata MA58MF14-7N" option in GUI, so i guess that the numbers of pulses are enough.

    2) I checked and the transducer is properly connected to the daughter card.

    3) Like i said in point 1, i used the "Default All General Registers for muRata MA58MF14-7N" option in GUI, so the transducer frequency is right.

    4) The photo below shows that the signal is being transmitted correctly.

    I have probed the signals from all 16 pins of PGA460, would be useful for you? Please, if you have another suggestion let me know. It would be very helpful.

    Regards,
    Maynard

  • Hello Maynard,

    The number of pulses required depends on the distance being measured. The "Default All General Registers for muRata MA58MF14-7N" will just implement a generic value of 16 for the transmitted pulses. The more pulses the device projects the higher the SPL it will have, meaning you should be able to detect a larger distance than if you were to transmit 2 pulses. The downside of this is that if you are trying to detect an item nearby you might miss the object because the transducer is still transmitting the pulse train. So my suggestion would be the following:

    1) Decrease record time to 12.28ms

    2) Place an item about 1.5m away

    3) Leave pulses at 16 default

    4) Set TVG at 74.5, select "All mid-code"

    5) Set Threshold at "All mid-code"

    We should observe an echo somewhat like the following:

    If your return signal does not look like this please check R36 on the daughtercard if using transformer driven mode. This should have a 0 ohm resistor in its path which connects the transmission transducer to the return path as well. If this is not present it would indicate why the customer is not seeing any signal on the return. If using direct driven side of the daughter card  the resistor to check would be R32.

    Best,

    Isaac

  • Hi Isaac,

    I just received response from customer, below is the details.

    "Sorry for the late answer. I have done all the suggestions from the post. The configuration steps for 1.5m measurement. And i also checked the R36 0 ohm resistor. But i still get the same data. Is there something else that i could do?"

    Regards,
    Maynard

  • Hello Maynard,

    If the customer has another EVM kit they could confirm that this device is indeed outputting the pulses.

    Was this the same problem that the customer was facing with the previous PGA460 before he replaced it or was this device replaced on the EVM for a different reason?

    Best,

    Isaac

  • Hi Isaac,

    According to the customer, they replaced it because they have damaged the original PGA. Before that it was working fine.

    Regards,
    Maynard

  • Hello Maynard,

    Has the customer identified what the problem was the first time with the original PGA460 was replaced? Perhaps if they were having the same problem with the original part the issue might be related to the board and not the device?

    Something else that could have gone wrong is if the new PGA460 was not installed properly, based on the communication with the GUI and seeing their burst captures I want to say that this might not be the issue but just in case  have they tried checking the soldering on the device to  the board,  to check if this was the problem?

    Best,

    Isaac

  • Hi Isaac,

    I just received response from customerAccording to customer, the original PGA460 was completed dead, it didn't get any signal at all. They have tested the soldering and according to them it is all fine.

    Regards,
    Maynard

  • Hey Maynard,

    Glad to hear the replacement worked!

    Best,

    Isaac

  •  Hi Isaac,

    I just confirm to the customer that there is no problem in the soldering however they still encountering the issue.

    Regards,
    Maynard

  • Hey Maynard,

    Thanks for the update, it seems like running out of options here. Based on the info it seems like it could be another component on the board could be damaged and could be source of this issue, my first area of suspicion would be the transducer. 

    It seems like the PGA460 was still bursting and sampling from the previous posts but we were never able to confirm if the transducer was actually generating the pulses. If they have a different transducer they could populate onto their board to test it out that would be the easiest option.

    I am not aware of other ways to test out ultrasonic transducer without pretty specific equipment. But here are some suggestions:

    I removed two working muRata MA58MF14-7N transducers off of a daughter card and measured the capacitance off of them at 1.5nF, if theirs measures differently then it could indicate that the transducer is not working. If they have another BOOSTXL-PGA460 they can set it to listen mode only and have it loop while the other one bursts to check if they can see those bursts coming onto the other system. Keep in mind this test would require another computer as well as the other EVM mentioned.

    The communication with the GUI and the PGA460 seemed to not have any connectivity issues so I believer the MSP board is most likely not the issue. The transmission showed earlier had a good voltage swing so I do not think the problem was the transformer. I hope these suggestions help.

    Best,

    Isaac