  We present a microwave source that is controlled by a commercially available
field programmable gate array (FPGA). Using an FPGA allows for precise control
of the time dependent microwave-dressing applied to a sample of trapped cold
atoms. We test our microwave source by exciting Rabi oscillations in a Na
spinor Bose-Einstein Condensate. We include, as supplements, the complete
source code, parts lists, pin connection diagrams, and schematics to make it
easy for any group to build and use this device.
