M2K MATLAB Class — User Guide

The M2K class wraps the libm2k C library to provide a clean MATLAB interface for the Analog Devices ADALM-2000 (M2K) hardware. It manages the device connection and exposes analog input (oscilloscope), analog output (waveform generator), and power supply functionality. You can perform all the operations you have previously done in Scopy by creating objects and calling methods in MATLAB through the M2K class.

References

• libm2k API documentation
• ADALM-2000 with MATLAB

Class Properties

Methods

Constructor — M2K()

Creates and initializes the M2K object. Automatically:
- Closes any existing M2K connections
- Opens a new connection to the device
- Calibrates both the ADC and DAC

myM2K = M2K();

Note: If the device is not detected, MATLAB will throw an error. Restart MATLAB, check the USB connection, and verify the search path.

clearM2K()

Closes all open M2K context connections. Called internally by the constructor; you can also call it manually for cleanup.

Make sure to always include clearM2K() at the end of your script to release the M2K port.

myM2K.clearM2K();

calibrateM2K()

Performs the ADC and DAC calibration routines.

myM2K.calibrateM2K();

Analog Input (Oscilloscope — Ch1, Ch2)

enableAnalogIn(channelNumber)

Enables an analog input channel. Must be called before reading samples.

Inputs:

myM2K.enableAnalogIn(1); % Enable Ch1
myM2K.enableAnalogIn(2); % Enable Ch2

setAnalogInSampleRate(ADC_rate)

Sets the ADC sample rate for both channels and confirms the new rate in the console.

Valid rates: 1k, 10k, 100k, 1M, 10M, 100M (samples per second)

myM2K.setAnalogInSampleRate(1e6); % 1 MSPS

getAnalogInSampleRate()

Reads the current ADC sampling rate of M2K.

curr_ADC_Rate = myM2K.getAnalogInSampleRate();

clearAnalogInSampleBuffer()

Flushes the ADC sample buffer by resetting the kernel buffers. Call this before getAnalogInSamples() to discard stale data.

myM2K.clearAnalogInSampleBuffer();

[t, ch1Samples, ch2Samples] = getAnalogInSamples(seconds)

Reads voltage samples from both Ch1 and Ch2 simultaneously.

Inputs:

Returns:

[t, Vin, Vout] = myM2K.getAnalogInSamples(0.1, 1000000);

Analog Output (Waveform Generator — W1, W2)

enableAnalogOut(channelNumber)

Enables an analog output channel. Must be called before pushing waveforms.

myM2K.enableAnalogOut(1); % Enable W1
myM2K.enableAnalogOut(2); % Enable W2

setAnalogOutSampleRate(DAC_rate)

Sets the DAC sampling rate for both W1 and W2, and confirms the new rate in the console.

Valid rates: 750, 7.5k, 75k, 750k, 7.5M, 75M (samples per second)

myM2K.setAnalogOutSampleRate(750e3); % 750 kSPS

getAnalogOutSampleRate()

Reads the current DAC sampling rate of M2K.

curr_DAC_Rate = myM2K.getAnalogOutSampleRate();

setWaveform(channelNumber, signalArray)

Generates a waveform on W1 or W2.

The following example requires the SignalLab class.

myM2K.setWaveform(1, signalArray);

Power Supply (V+, V−)

enablePowerSupply(supplyNumber)

Enables V+ or V-.

Inputs:
| Parameter | Values | Description |
|-----------------|--------|-------------|
| supplyNumber | 1 | Enable V+ |
| supplyNumber | 2 | Enable V− |

myM2K.enablePowerSupply(1); % Enable V+
myM2K.enablePowerSupply(2); % Enable V-

setPowerSupply(supplyNumber, voltage)

Sets the output voltage for a specified power supply.

Inputs:

myM2K.setPowerSupply(1, 3.1); % Set V+ to 3.1V
myM2K.setPowerSupply(2, -2.8); % Set V- to -2.8V

Note: V+ accepts positive voltage value only. V- accepts negative voltage value only.

Example — Plotting a Signal in Time and Frequency Domains

This example first generates a sine wave using the SignalLab class, pushes the generated signal to M2K's waveform generator (W1), reads W1 through 1+/1-, then plots the received signal in both time and frequency domains.

Make sure to include both the M2K class and the SignalLab class in your working directory.

Connect 1+ with W1, 1- with GND.

% Before connecting the M2K with your circuit, run this block fo code.

% This ensures the accuracy of the calibration procedure
myM2K = M2K(); % create M2K object
myM2K.enableAnalogIn(1); % enable Ch1
myM2K.enableAnalogIn(2); % enable Ch2
myM2K.enableAnalogOut(1); % enable W1

% After connecting M2K with your circuit, run this block of code.

Vpp = 2; % waveform peak to peak is 2V
waveFreq = 1000; % frequency of the waveform is 1 kHz

ADCRate = 1000000; % ADC rate = 1MHz 
DACRate = 750000; % DAC rate = 750kHz

% set the ADC and DAC rates
myM2K.setAnalogOutSampleRate(DACRate);
myM2K.setAnalogInSampleRate(ADCRate);

% use signalLab to generate a 2 Vpp, 1 kHz sine wave
% the sampling frequency is the DAC rate because the generated signal is used by M2K's W1
s_generated = SignalLab(Vpp / 2, waveFreq, DACRate);
s_generated.info()
% generate siganl
[t_generated, samples_generated] = s_generated.generate(0.01);

% plot the generated signal in time and frequency domains 
figure;
s_generated.plotSignal(t_generated, samples_generated);
title(sprintf('Generated %s Signal --- Time Domain', s_generated.waveType));
figure;
s_generated.plotSpectrum(samples_generated);
title(sprintf('Generated %s Signal --- Frequency Domain', s_generated.waveType));

% push the generated signal to M2K waveform generator W1
myM2K.setWaveform(1, samples_generated);
% clear the ADC buffer
myM2K.clearAnalogInSampleBuffer();
% read 10 periods of the received signals from Ch1 and Ch2 
[t_received, ch1_samples, ch2_samples] = myM2K.getAnalogInSamples(10 / waveFreq);


% create another signalLab object with the ADC sampling rate
% the sampling frequency is the ADC rate because the received signal is read by M2K's Ch1(1+/1-)
s_received = s_generated;
s_received.samplingRate = ADCRate;
s_received.info()

% plot the received signal in time and frequency domains 
figure;
s_received.plotSignal(t_received, ch1_samples);
title(sprintf('Received %s Signal --- Time Domain', s_received.waveType));
figure;
s_received.plotSpectrum(ch1_samples);
title(sprintf('Received %s Signal --- Frequency Domain', s_received.waveType));

Quick-Reference Card

Troubleshooting

• Can't register M2K:
• Check USB connection.
• Ensure Scopy is closed so it is not holding the serial port.
• Check if M2K.m is in your working directory.
• Check if libm2k is in your search path.
• Restart MATLAB.

• Call clearM2K() by the end or at the beginning of your script.

• Invalid ADC/DAC Rate

• Only set the sample rate to a valid value.
• Valid ADC rates: 1k, 10k, 100k, 1M, 10M, 100M (samples per second).

• Valid DAC rates: 750, 7.5k, 75k, 750k, 7.5M, 75M (samples per second).

• Captured waveforms are off

• Call clearAnalogInSampleBuffer() before getAnalogInSamples().
• Make sure your ADC rate is above the Nyquist rate.