Destruction of the Analog Discovery 2 module

[David Blu]

To whom it may concern,

I am in the process of developing connections between a custom made potentio-stadt board that I am creating for a customer.   We are deeply concerned that we could inadvertently destroy our newly purchased Analog Discovery 2 module that we have connect to this costumed made potentio-stadt board.   

 

The Connections between our costumed made potentio-stadt board and the Analog Discovery 2  module are as follows:

 

POTENTIO-STADT    BOARD                               IS CONNECTED TO THE                                            ANALOG DISCOVERY 2 MODULE:   

START OF ANALOG CONNECTIONS-------------------------------------------------------------------------------------------------------

 

UNIPOLAR DAC VOLTAGE POTENTIAL (0-3.3 VOLTS)         CONNECTS  -------------- >       YELLOW WIRE ON WAVEFORM ONE  (W1)

UNIPOLAR DAC ONE OFFSET   (0-3.3 VOLTS)          CONNECTS --------------- >          YELLOW-WHITE WIRE ON WAVEFORM  TWO (W2)

BIPOLAR REFLECTOR SW6                                         CONNECTS ---------------- >                BLUE WIRE OR OSCILLISCOPE CHAN 2 (2+).

BIPOLAR GROUND FOR REFLECTOR SW6                CONNECTS ----------------- >       BLUE-WHITE WIRE OR OSCILLISCOPE CHAN 2 (2-)

 BIPOLAR CURRENT-OUT-VOLTAGE                          CONNECTS ----------------- >         ORANGE WIRE OR OSCILLISCOPE  CHAN 1 (1+)

GROUND                                                                       CONNECTS ----------------- >         ORANGE-WHITE OR OSCILLISCOPE CHAN (1 -) 

 

END OF ANALOG CONNECTIONS--------------------------------------------------------------------------------------------------------

 

START OF DIGITAL CONNECTIONS-------------------------------------------------------------------------------------------------------

RELAY SWITCH                                                             CONNECTS ------------------->       GREEN WIRE OR 5 I/O     (-5 TO 5.0 VOLTS)  

 PIN A0                                                                     CONNECTS ---------------------->        PURPLE WIRE OR 6 I/O    (-5 TO 5.0 VOLTS)

PIN ENABLE                                                             CONNECTS ----------------->      BROWN WHITE WIRE OR 15 I/O  (-5 TO 5 VOLTS)

A1                                                                              CONNECTS  -------------------->     BROWN WIRE  OR 7 I/O (-5 TO 5.0 VOLTS).  

A2                                                                              CONNECTS -------------------->      PURPLE-WHITE WIRE OR 14 I/O  (-5 TO 5.0 VOLTS).

AO, ENABLE, A1, AND A2 ARE APART OF A MULTIPLEXER CIRCUIT.   

END OF DIGITAL CONNECTIONS-------------------------------------------------------------------------------------------------------

 

Also, there has been a patchboard made by connecting all of the following ground connections such as 1- for oscilliscope chan one, 2- for oscilliscope chan two, and all of the ground connection pins on the Analog Discovery 2 module have all been connected to a common ground point on the project potentio-stadt board which is the ground point.  

Is this allowed or will this cause destruction to either the potnetio-stadt board we are constructing or cause desctruction to the analog discovery 2 module???   Please help us resolve this potential lethal problem and issue.  

Respectfully,

David Blu

 

[JColvin]

Hi @David Blu,

I have moved your question to a more appropriate section of the Forum.

To answer your question about keeping common ground connections between the Analog Discovery 2 and the device under test, yes that is the recommended practice. Not having a common ground between the two devices can easily be a way for one or both devices to become damaged.

As for the connections themselves in your described situation, the analog connections seem appropriate and compliant with the Analog Discovery 2 specifications, https://reference.digilentinc.com/reference/test-and-measurement/analog-discovery-2/specifications, presuming that the bipolar reflector sw6 attached to Oscilloscope Channel 2+ and the bipolar current-out-voltage attached to Oscilloscope Channel 1+ are between the range of -25V to +25V with respect to ground.

The digital connections seem problematic. The Analog Discovery 2 digital I/O pins are designed to be used with 1.8 or 3.3V LVCMOS logic and are tolerant of 5V input signals (they do not provide 5V signals themselves).
However, each of the digital connections you have list a voltage range of -5V to +5V and my understanding is that the Analog Discovery 2 isn't specifically designed to work with that digital voltage range. The Analog Discovery 2 reference manual does state that overvoltage up to +/- 20V is supported, but I think that is specifically for spikes as opposed to constant usage. @attila do you have some more specific feedback on this?

Thanks,
JColvin

[David Blu]

THANK YOU FOR YOUR RESPONSE JColvin !!!

 

I greatly appreciate it !!!

 

Looking at your detailed answer now !!!  GREAT WORK !!!

 

David

[David Blu]

OH I  apologize.   

 

I made a mistake...   The -5.0 volt to +5.0 volt was meant for the analog connections with a ground.   The digital lines are only (0 volts or ground) to +5.0 volts.   Is this electrically compatible ??   Please forgive my mistake !!!

 

Respectfully,

 

David Blubaugh

[JColvin]

Hi @David Blu,

That is alright. The -5.0V to +5.0V is definitely compatible with the analog channels.

As for the digital signals, the Analog Discovery 2 can safely receive and analyze 5V digital inputs, though it cannot in turn provide 5V output digital signals.

Please let me know if you have any further questions.

Thanks,
JColvin

[David Blu]

Thank You for timely response !!!

I greatly appreciate it !!!

OK  I do have one more question.  In regards to the Analog Discovery 2 module itself.  IS IT POSSIBLE to develop a C/C++, C#, or Python program that controls the functionality of the Analog Discovery 2 module and then be able to download that same program written in either C/C++, C#, or Python into the actual Analog Discovery 2 module itself.  IN A WAY, turning the Analog Discovery 2 module into an self-controlled embedded system without the need of the waveforms environment.   I know one can develop programs on the laptop that then controls the Analog Discovery 2 module, but is it possible to then download that same program into the actual analog discovery 2 module itself thus creating a FPGA powered embedded system..   Is any of this possible???  

If this is possible, could one also store and later process data points of oscilloscope capture points acquired by the Analog Discovery 2 module acting in the form of an embedded systems device???    

Thank you once again for all of your help.   

 

Respectfully,

 

David Blubaugh

[JColvin]

Hi @David Blu,

What you are describing is not possible on the Analog Discovery 2; you are not able to run it as a standalone system, you will always need an external host to start and control the device.

Such functionality is possible on the Analog Discovery Pro though as it has an SoC at its core and comes with a basic Linux image and WaveForms SDK preinstalled, so you create a script that is then run on the module on power up or whenever you trigger it to run in Linux and store the data on an attached flash drive or something similar.

Thanks,
JColvin

[David Blu]

OK Is it possible to connect the analog discovery 2 module with the raspberry pi 4???   

From that arrangement could we develop an embedded systems from that arrangement ???  

thanks,

David Blubaugh

 

[attila]

Hi @David Blu

Yes, it should be possible depending on you requirements.

There were USB communication problems with previous RPi versions and earlier drivers but the RPi4 and new driver is fine.

The Analog Discovery Pro 3000 would provide much better performance since it is fully embedded. The Linux and the DSP run in the same chip. The Zynq chip contains the processing system, which has low latency and high transfer rate with the PL/FPGA, this pre-processing the ADC, DAC and digital data.