Changes

To run the examples, you will need to ensure you set the MATLAB working directory to the location of the .m script files. Since the new CW 4,0 API exposes the internals of chipwhisperer the easiest way to get access to the chipwhisperer module in MATLAB is to use this API. MATLAB seems to not find certain modules even if they are on the python path so just use pythons build in importlib, which MATLAB can find, letting python find the module for MATLAB. Running Run this command in MATLAB.

>> [cw , scope, target] = py.importlib.import_modulecwconnect('chipwhisperer')

or <pre> >> [cw, scope, target] = cwconnect(int64(1250), int64(3000))</pre>where the first argument is the default offset, and the second argument is default number of samples. This command should give you access to return the 4.0 API, scope object, and target object, each having their own interface.

If this works it should print the information about the 'cw', 'scope' and 'target' object:

If this FAILS, you may need to simply unplug/replug the ChipWhisperer-Lite. You may have not closed the connection from the previous test.  == Interfacing with AES ==What you probably want to do is capture a trace during AES encryption, to test your side channel skills in MATLAB. You can do this by running<syntaxhighlight lang=matlab> >> [textout, trace] = measure_AES(scope, target, [0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15],[0 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15])</syntaxhighlight>This will return the cipher-text and the power trace.  == 4.0 API Notes ==Once the <code>cwconnect.m</code> function is executed you have access to the scope and target options, which are part of the new exposed API in <code>chipwhisperer</code>. To list the properties that are available type this inside your MATLAB interpreter:<pre> >> scope</pre>This should print the MATLAb output for the scope object but python also prints the attributes you can change and customize. The output should look like this:<pre>scope =   Python OpenADC with properties:  connectStatus: [1×1 py.chipwhisperer.common.utils.util.Observable] scopetype: [1×1 py.chipwhisperer.capture.scopes.openadc_interface.naeusbchip.OpenADCInterface_NAEUSBChip] digitalPattern: [1×1 py.NoneType] adc: [1×1 py.chipwhisperer.capture.scopes._OpenADCInterface.TriggerSettings] params: [1×1 py.chipwhisperer.common.utils.parameter.Parameter] qtadc: [1×1 py.chipwhisperer.capture.scopes._qt.OpenADCQt] advancedSettings: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererExtra.ChipWhispererExtra] trigger: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererExtra.TriggerSettings] refreshTimer: [1×1 py.chipwhisperer.common.utils.timer.FakeQTimer] glitch: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererGlitch.GlitchSettings] advancedSAD: [1×1 py.NoneType] clock: [1×1 py.chipwhisperer.capture.scopes._OpenADCInterface.ClockSettings] gain: [1×1 py.chipwhisperer.capture.scopes._OpenADCInterface.GainSettings] channels: [1×1 py.list] io: [1×1 py.chipwhisperer.capture.scopes.cwhardware.ChipWhispererExtra.GPIOSettings]  cwlite Device gain = mode = low gain = 45 db = 22.50390625 adc = state = False basic_mode = rising_edge timeout = 2 offset = 1250 presamples = 0 samples = 3000 decimate = 1 trig_count = 173067711 clock = adc_src = clkgen_x4 adc_phase = 0 adc_freq = 29538471 adc_rate = 29538471 adc_locked = True freq_ctr = 0 freq_ctr_src = extclk clkgen_src = system extclk_freq = 10000000 clkgen_mul = 2 clkgen_div = 26 clkgen_freq = 7384615 clkgen_locked = True trigger = triggers = tio4 module = basic io = tio1 = serial_rx tio2 = serial_tx tio3 = high_z tio4 = high_z pdid = high_z pdic = high_z nrst = high_z glitch_hp = False glitch_lp = False extclk_src = hs1 hs2 = clkgen target_pwr = True glitch = clk_src = target width = 10.15625 width_fine = 0 offset = 10.15625 offset_fine = 0 trigger_src = manual arm_timing = after_scope ext_offset = 0 repeat = 1 output = clock_xor</pre>So to change the offset we set earlier with the matlab function we could do this:<pre> >> scope.adc.offset = int64(1500);</pre>The <code>int64()</code> function is needed so matlab does not pass a string through to the python function. We can see that the value has now changed by running:<pre> >> scope.adc.offset</pre>with this result:<pre>ans =  int64  1500</pre><b>Note : it is good practice to check what type the attribute of the scope and target objects is, so you can assign the correct type using MATALB's int64()...etc functions.</b> === Manual 4.0 API Usage ===To import the chipwhisperer python module into MATLAB run<pre> >> cw = py.importlib.import_module('chipwhisperer')</pre>This will work as long as you have the <code>chipwhisperer</code> module on your python path or system path. You can actually interact directly with the 'cw' as in Python, just as you would after running <code> import chipwhisperer as cw </code> in Python. So you can initialize a scope and a target like so:

You can now write scripts in MATLAB similar Do some fun things with your chipwhisperer tool, like follow a wiki tutorial (you will just have to implement the scripts in [[Making_Scripts]]examples with MATLAB instead), and close the connection when you are done:<syntaxhighlight lang=matlab> >> scope.dis() >> target.dis()</syntaxhighlight>