External oscilloscope

When I use my own oscilloscope to collect traces, there is no trace display. Is it because the power consumption is too low? If so, what should I do?

When you say there’s no trace display what do you mean? Is the scope not triggering, do you not see much of a signal, or is there something else?

There is no signal in my scope.

This seems like it might be an issue on the side of your scope. Confirm a few things:

  1. Your scope is being triggered by the target at the beginning of the encryption.
  2. Your scope probe is AC-coupled
  3. You’re measuring from the correct point on the ChipWhisperer


All the above conditions are met.We can see the trigger signal but cannot capture the power trace.By the way,how to use CW308-STM32F303 alone ?

Can you attach a picture of a power trace?

There shouldn’t be any sort of issues with signal/voltage levels. For reference, I have my scope set on 50mV/division and the power trace is clearly visible. Also, if you have it, I’d recommend using a BNC to SMA cable.

Here’s my power trace for reference:


There’s a 5V DC power jack on the board that you can use to power it. Other than that, you’ll need something to communicate over serial with the F3. Make sure the voltage level is 3.3V. Also, when building the firmware, use make PLATFORM=CW308_STM32F3 CRYPTO_TARGET=TINYAES128C EXTRA_OPTS=USE_INTERNAL_CLK to make the STM32F3 use its internal oscillator for its clock. IIRC it’s 8MHz instead of 7.37MHz, so you might have to adjust the baud rate a little as well.


Am I wired like this? Please correct me if there is an error.

I think your scope signal on 2 is DC coupled. You’ll want it on AC coupling.