Issue: Noise as output


#1

Dear Members,
All of sudden, I am getting noise as output when I am recording traces using ChipWishper Rev2 board. We have tried with different targets (XMEGA 12804). But we still receiving noise as output. Here, you can see a snapshot. I am quite new to Embedded hardware, and don’t have sufficient knowledge on hardware boards. Kindly, please help me.


#2

Hi Satya,

Please check that:

  1. The DCM for the ADC is locked. This should be under the ADC settings under Scope Settings.
  2. You have an SMA cable connecting the ChipWhisperer board to the CW308 target board.

If you’re still running into issues, can you please send me your scope settings? Running print scope in the Python console should be sufficient.

Alex


#3

Thank you Alex for your prompt reply. I see that DCM in ADC is disabled for me. I am using SMA cable actually. Please check the scope settings,

Thanks in advance for your help. Please guide me in this regard.


#4

Hi Satya,

There should be a Reset ADC DCM button under ADC Settings in Scope Settings. Try hitting that a few times, as the DCM may not lock after settings a new clock frequency. I don’t think there’s anything else wrong with your settings.

Let me know if you still have issues,

Alex


#5

Hi Alex,
Thanks for your suggestions. I have tried the options you mentioned. However, I don’t see any luck yet. Could you please suggest me any other alternatives?

Thanks in advance,

Best regards
Satya


#6

Hi Satya,

A few questions:

  • What target board are you using? Are you using the multi-target board?
  • What connections do you have between the target board and the CW Rev 2? Specifically, where are the SMA connectors you’re using connected? Is VOUT on the target connected to the Channel A LNA on the target?

I’m guessing your CW Rev 2 isn’t receiving any signal at all, so that probably points to a connection issue between the Rev 2 board and the target.

Alex


#7

Hi Alex,

  • I am using ATMEL XMEGA 12804 target board. We do have multi-target board. But, I have tried on single and multi-target board as well. In both cases, I see the same result noise.
  • I have CW Lite 1200. SMA is connected from “measure” pin on CW 1200 to “measure” pin on target board. Frankly speaking, I don’t see VOUT and channel A LNA options.

As you mentioned, I am also thinking the same. There might be some connection issues between CW and target.

Thanks
Satya


#8

Hi Satya,

The LNA connection is available on the CW Rev 2, which is a different board than the CWLite. Can you please confirm your hardware setup? Are you using the CW1173 ChipWhisperer Lite (https://wiki.newae.com/CW1173_ChipWhisperer-Lite) to capture? Are you using the CW303 XMEGA target (https://wiki.newae.com/CW303_XMEGA_Target)?

Alex


#9

Hi Alex,
Thanks for your time. I am using CW1173 Lite to capture, and CW303 as a target. Thanks again for pointing me to correct boards.

Please kindly let me know if there is any procedure associated to these specific boards?

Thanks
Satya


#10

Hi Satya,

There shouldn’t be any additional setup needed besides using a 20pin cable and an SMA cable to connect the two boards. If you have a multimeter on hand, can you check the resistance between the center measure pin on the CWLite and JP7 (or SJ4) on the CW303 with the cable in?

Alex


#11

Hi Alex,
Thanks for pointing to me here. I have found that one capacitor is partially broken (C68) from the board. I hope if I manage to fix this, it may work again.

Thanks for your support.

Best regards
Satya


#12

Hi Satya,

Looks like C68 is the AC coupling cap for the measure input, so that being broken would definitely explain things. You may want to try returning the device, but if you need to replace the cap yourself, here’s a digikey link to the cap we use: https://www.digikey.ca/products/en?keywords=490-1519-1-ND (out of stock, but it’s just a generic cap so you can probably find a similar one pretty easily with the same specs).

Alex