The XMultiKit and Xmegalab can output the standard waveforms of a function generator and can adjust the frequency, amplitude, offset and duty cycle of the selected waveform.
The waveform is stored in a 256 byte long buffer, this buffer is fed to the XMEGA's DAC thru the DMA. Once the waveform is set, the waveform will be generated without any CPU intervention. The maximum conversion rate of the DAC is 1MSPS, this limits the maximum output frequency of the AWG as a system.For example, if the AWG is generating a sinewave with 256 points, the maximum frequency is 3906.25Hz. If generating a sinewave with only 32 points, the maximum frequency is 31.25KHz. The AWG amplifier has a cut off frequency of 66KHz.
The predefined waveforms of the AWG are:
By modifying the source code, any kind of waveform can be generated on the AWG.
Buttons KA thru KE select the waveform.
The numbers on the keypad select predefined frequencies:
Pressing the number 0 on the keypad will set the offset to 0V.
Pressing the # on the keypad will toggle the behaviour of the rotary encoders:
|Encoder 1||Encoder 2|
|Mode 2||Offset||Duty Cycle|
To exit, press *. The AWG will continue to output the waveform.