Generate Standard Periodic Waveforms Using Digilent Analog Discovery
Use function generator channels to generate a 1 kHz sinusoidal waveform, and record data at the same time, using an analog input channel.
Discover Digilent Devices
Discover Digilent devices connected to your system using daqlist
daqlist("digilent") dq = daq("digilent")
ans = 1×4 table DeviceID Description Model DeviceInfo ________ _____________________________________________ ____________________ _______________________ "AD1" "Digilent Inc. Analog Discovery 2 Kit Rev. C" "Analog Discovery 2" [1×1 daq.di.DeviceInfo] dq = DataAcquisition using Digilent Inc. hardware: Running: 0 Rate: 10000 NumScansAvailable: 0 NumScansAcquired: 0 NumScansQueued: 0 NumScansOutputByHardware: 0 RateLimit: [] Show channels Show properties and methods
Add a Function Generator Channel
Add a function generator channel with device ID AD1
and channel ID 1
. Set the waveform type to Sine
.
ch_fgen = addoutput(dq, "AD1", "1", "Sine");
Set Channel Properties
Set channel gain to 5 (sets the amplitude of the sinusoid to 5 V). Assign the gain to a variable.
ch_fgen.Name = "AD1_1_fgen"
gain = 5;
ch_fgen.Gain = gain;
ch_fgen = Index Type Device Channel Measurement Type Range Name _____ ______ ______ _______ ________________ ____________________ ____________ 1 "fgen" "AD1" "1" "Sine" "-5.0 to +5.0 Volts" "AD1_1_fgen"
Set the signal frequency to 1 kHz
ch_fgen.Frequency = 1000;
Add an Analog Input Channel
Add an analog input channel with device ID AD1
and channel ID 1
. Set the measurement type to Voltage
.
ch_in = addinput(dq, "AD1", "1", "Voltage"); ch_in.Name = "AD1_1_in"
ch_in = Index Type Device Channel Measurement Type Range Name _____ ____ ______ _______ ________________ __________________ __________ 1 "ai" "AD1" "1" "Voltage (Diff)" "-25 to +25 Volts" "AD1_1_in"
Set DataAcquisition Properties
Acquire data at a higher scan rate than the highest frequency in the generated waveform.
dq.Rate = 100 * ch_fgen.Frequency;
Generate a Periodic Waveform and Record Input
[data, startTime] = read(dq, seconds(1));
Plot Data
period = 1/ch_fgen.Frequency; plot(data.Time, data.AD1_1_in); xlabel('Time in seconds'); ylabel('Voltage in volts'); title(['Period = ', num2str(period), ' seconds']) xlim([seconds(0) seconds(5*period)]); ylim([-gain gain]);