Question about Programing the Wulpus Boards

[Daalvarenga]

Hello Sergio we custom made the boards according to the files located on the github. I have been trying to program them but have yet to have success. I would like to ask which procedures would be best followed for the programing of the boards? The ones on the current user manual located on the GitHub?
Or the instruction on the GitHub of how to flash the nrf52 and msp430.

I also have a question the NRF-SWD adapter is it using a 20 pin SWD pinout right? In my case we do not have a 20 pin J-link programmer but a 10 pin edu mini so what i am planning to do is connecting the edu mini to the NRF-SWD adapter using wires and then just running the code normally.

[Sergio5714]

Hello @Daalvarenga , thank you for your message!

1. I would recommend following the User Manual, since it has the most updated information. And please let me know if you found any confusions or discrepancies between the User Manual and READMEs

2. Regarding the NRF-SWD adapter, we did take this design from a previous project; and I did not verify the compatibility with 20 pin SWD cable. I would recommend connection through the dupont jumper cables.

Please, let me know if you have further questions.

Best regards,
Sergei

[Daalvarenga]

Hello @Sergio5714

1. For the Readme for programing the MSP430 it is different between the readme and the manual. The readme has less steps to follow currently than on the manual.
2. For the NRF-SWD adapter which one is the pinout that I should follow ? Is it the same pinout as the Jtag Mr. Wolf adapter that appears on the manual?

[Sergio5714]

Hello @Daalvarenga, thank you for the comment, and I am sorry for the delayed reply.

1. Thank you for reporting. We will try to fix it in the next release.
2. The pinout may not be the same. Please double-check the schematics of the acquisition board and trace the signals through the Molex connector. I am attaching the relevant schematics screenshot to the message
   

I hope this helps.
Best regards,
Sergei

[Daalvarenga]

Hello Sergio, wanted to tell you that I did double check the schematics of the acquisition board and the screenshot image you shared where the correct configuration to follow for the molex connector.

We are still having a problem with the programing of the boards. Currently I have been able to run the code without a noticeable error, but i am still not able to reproduce properly the signal that we have with the Wulpus board you sent to the lab.

We use the exact same ultrasound transducer and parameters but the signal is still not replicated properly. I do know at least there is connection between the acquisition board and the USB dongle because to test it out I gave it the same number to the Wulpus acquisition board and USB receiver dongle as the one you sent. The USB receiver dongle i programmed can be used with the Wulpus board you sent and the signal would still be the same. But the moment I try to use the Wulpus board I programed there is barely any reading from the signal.

ezyZip.mp4

[Sergio5714]

Hello @Daalvarenga , thank you for the comprehensive description. Here are my observations:

• The gain of the PGA looks too high (based on the "correct signal"). The RX signal seems close to saturation, so I would lower the gain.
• The problem why you don't see the same signal is probably connected to the timings of HV multiplexer (HV MUX RX start time). If it is switched too early, it can block HV from propagating to the transducer so that no excitation event happens. And if there is no excitation, there will be complete silence at receive.

My suggestion is to debug with the following steps:

1. Capture Excitation waveform at transducer connector.
2. If the excitation waveform at the transducer connector is not presented, measure it at the output of the MOSFET drivers (i.e. before multiplexers). If it is measurable at the driver's output, then increase the HV MUX RX start time (in the GUI) until you see excitation output at the transducer connector.
3. If it is not measurable at the MOSFET driver's output, probe the input of the MOSFET driver and the +HV power output.
4. If the +HV voltage output does not reach high values, consider lowering DC-DC turn on time (e.g. to 100 us) to guarantee that there is enough time to accumulate the charge for pulsing.

These steps should help to isolate the problem.
I hope the problem is only in the configuring of the HV MUX RX start time (which may vary from probe to probe).

Don't hesitate to ask further questions.

Best regards,
Sergei

[Daalvarenga]

Hello Sergio,
I was able to capture the excitation waveform of the working wulpus (rectangular signal of about 15volts) once i tried it on the wulpus boards i programmed. there was no signal. I will proceed with steps 2-4. Before I continue I would just like to make sure I'm measuring the correct components.
For step 2 i should measure the mosfet driver components (labeled 2 on the image of the manual).
Step 3 would be the the high voltage supply components (labeled 3 on the image).

Something important I would like to mention is that I tried some troubleshooting and I exchanged the HV PCB that is working and placed it on the Acquisition PCBs i have programed and it was able to produce the exact same signal as how the working board should. Then I placed the HV PCBs we made to the working Acquisition PCB and produced a similar flatline signal. I examined the boards and noticed a slight difference in one of the components.

The one to the right is HV PCB that is of the working board. If you notice the Inductor (L1 which should be B82422A1103K100) does look different. The working one says 103k 1203, the one on the left says 103k 3407. Although the different numbers i believe could be manufacturing dates. They do have the same resistance and conductivity though. Is it possible that the whole difference is only because of the HV PCB and maybe some components? If it is the personnel of the ECE department did say they could exchange the components if we obtained the correct ones.

I will continue trying to modify the HV MUX RX start time on the meantime to see if I manage to get it to work properly.

[Sergio5714]

@Daalvarenga , thank you for your message.

Indeed, then there is a problem with HV PCB but all the same debugging steps can be applied.

Your understanding of areas to measure are correct.

Regarding the inductance, based on your measurements and part numbers, it should be OK.

Instead, please check the polarity of the diode D1 near the inductor (check "BD" marking on the package).
It is easy to mount it in the wrong way and then HV will not be generated (hence, no excitation). Use the following picture as a reference.

Best regards,
Sergei

[Daalvarenga]

Hello Sergei,

i checked the polarity the Diodes of the boards we had in comparison to the working ones we had. And also the image, it turns out they where connected with inverted polarity, we flipped them and now everything works perfectly as it should.

I did notice there is a slight difference on the signal between boards even when I change the HV boards between them, it is normal right?

Thank You for your help, now I will be able to properly collect data for my project.

Board #16 (The working one we had)

Board#17 (Board we programed)

Board #7 (Board we programed)

[Sergio5714]

@Daalvarenga, happy to hear that you fixed the problem! Diodes polarity is a classical assembly problem: we have also faced it multiple time!

There could be a small difference between the boards, primarily because per current MSP firmware HV TX MUX start time depends on the wake-up time of some internal circuits, Which do have some variability from probe to probe.

I would still suggest you reducing the gain significantly, since your signal is saturated. Make it around 2 times lower for better signal quality.