MSP430FR6047: Device stopped working after performing measurements with some hot water

Hi Jack,

Does the device recover after a power cycle? There is a calibration sequence that runs, but I don't believe it will store values on the device between resets. I will confirm with my team.

Regards,

Evan

Hi Evan,

Thanks for your reply!

No, turning it off and on again didn't help. It was of course the first thing I tried.

I look forward to the outcome of your discussion with your team!

Best regards,

Jack

The only way to really "factory reset" is to reprogram the device through CCS or IAR with the "MSP430FR6047EVM_USS_Water_Demo". Everything in FRAM will be erased and all of the parameters in your USS_userConfig.h will be your starting point.

Hi Jack,

You can try re-programming the board with the water demo.  That will clear anything lingering in FRAM.  But first, while connected to the GUI, can you do an ADC capture?  What do you see?

Hi Seth,

I have tried re-installing the demo a few times (the latest version, from April 2020), flash it using UinFlash, and then opening the GUI, but still get the error that there are no signals connected.

Hi Dennis,

I tried re-installing the demo a few times (the latest version, from April 2020), flash it using UinFlash, and then opening the GUI, but still get the error that there are no signals connected.

This is how the captured signals look now (left) compared to how they looked before (right).

Hi Jack - the left plot is disturbing.  This is looking like something related to your sensors or pipe.  When you "added some hot water", do you know the approx water temperature during the measurements?  Do you have more than one pair of transducers and if so did you try another pair to see if they have same behavior after exposure to heated water?

Hi Dennis,

I have a couple other sensors which I am testing, but they all give something similar to the left plot. I poured the water approx. after 10min coming out of the boiler.

The sensors and the pipe are in good condition because I used another evaluation board and did measurements with water at room temperature and get nice signals. I'm a bit afraid to use hot water again since I don't want the board to "break".

So the problem is somehow in the board, and since I don't have an electronics background, I don't have the resolution to know where to start finding where it is, and whether it can be fixed.

Hi Jack,

Most likely, the increased water temperature increases the speed of sound or decreases the tof (time of flight), which means your ADC capture is happening too late.  Try using a smaller value for the 'Gap between pulse start and ADC capture'.  You may have to try a couple different values until you see the waveform on the right.

Hi Dennis,

Although what you say is absolutely right, I compensated for this the first time I did the measurement.

However, when I wanted to do the measurement again with water at room temperature, and with the original settings that I know they work, then the signals are not being captured properly. This is my problem.

It has to be something in the board which got damaged, because if I try a new one, then it works perfectly again.

Hi Jack - Let me make sure I got this correct.

You have 2 EVM pcbs.  EVM #1 works correctly when pipe/sensors are subjected to room temp and hot water.   EVM #2 does not work correctly under the same conditions when using the same pipe/sensors as used with EVM #1,  correct?

If they are both programmed with same firmware then I would agree something is not correct with EVM #2.  Where did you purchase these EVMs from?

Correct Dennis.

I got them for free directly from TI, since the company I work at has been a long-term client.

Hi Jack,

Ok, let me see what I can do on my end.

Great Dennis! Thanks a lot!
BTW, could it be possible to get a few more of those EVMs in the meantime? I'm doing a lot of tests at the moment, and I don't want to run-out of working EVMs. Perhaps you have an email I can write you to? Thanks!

Hi Jack,

I have reached out to our sales/technical team covering this account.  They will provide assistance with your request.

Jack - has someone from our sales/technical team contacted you regarding this issue?

Hi Dennis.

Yes, Holger contacted me. Thanks!

He will send some EVMs, but I still don't know the reason for the effects we are discussing.

Hi Jack,

Sorry for delayed response.

Jack Massaad said:

I poured the water approx. after 10min coming out of the boiler.

Remind me again, what is the actual temperature of the water when applied to the sensors?  If you don't know, please measure. 

Hi Dennis,

The temperature was approx. 90 degrees Celsius.

Hi Jack,

Sorry to go in circles on this, but I want to make sure I fully understand the scenarios.

From your previous response you do have one of the EVMs that works correctly when subjected to both room temp +90C water - do I understand that correctly?

Regarding this behavior, I'm not sure what is the cause.  All I can go on at the moment is one EVM works and the other doesn't.  When you get your replacement, let's see how it performs, then we can try to figure out what is the failure mechanism on that one EVM.

Also, I will send you a friend request.  Please respond and I can provide my email there.

Hi Dennis,

The events were like this:

1. Performed measurements with water at room temperature.

2. Performed measurements with hot water.

3. Wanted to perform measurements with cold water again, but the signals are not captured by the GUI. And it also shows an error that there are no signals connected upstream and downstream channels.

The curious thing is, in step 3, if I hook-up an oscilloscope to CH0 and CH1, I see the transmitted and received signals. This also means that the sensor is not broken, and that the chip seems to still transmit and receive something. But I can't see it in the GUI.

I hope this summarizes what happens.

Oh, and all this happened with the same EVM.

Hi Jack,  is it possible to test with 50C water, then 75C water to get a couple of in between data points?

Hi Dennis,

Apologies for the late reply.

Actually, I'm a bit afraid to put relatively hot water again and keep "damaging" more boards. I was thinking that perhaps I could send you the board so you could examine it more closely? If you also think this is a good idea, please let me know an address I could send it to you.

Hi Jack,

Let me know if you have decided to ship one of the PCBs to me.