When your board is nearing completion, you should check operation of the DDS.
The sketch AD9834_Test.ino switches the DDS output between two frequencies in the CW portion of the 40m band at a 1Hz rate. If you tune a receiver close to 7 MHz or 7.03 MHz, you'll hear carrier bursts if all is well.
Those with access to an oscilloscope can check for the presence of a sinusoidal voltage between pin 'S1' and 'Gnd' of the 'm0xpd RF Bus' (which is located on the same edge of the board as the USB socket). This voltage should be at an amplitude of approximately 600mV pk - pk (approx 200 mV RMS) when unloaded.
The subroutines included within the AD9834_Test.ino sketch emphasize how simple it is to control the DDS module.