CONDENSED UNAUDITED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands	3 Months Ended
	Apr. 03, 2016	Mar. 29, 2015
Income Statement [Abstract]
Revenue	$ 2,950	$ 6,159
Cost of revenue	1,794	3,280
Gross profit	1,156	2,879
Operating expenses:
Research and development	3,447	3,477
Selling, general and administrative	2,693	2,960
Total operating expenses	6,140	6,437
Loss from operations	(4,984)	(3,558)
Interest expense	(38)	(14)
Interest income and other expense, net	(7)	(26)
Loss before income taxes	(5,029)	(3,598)
Provision for income taxes	64	40
Net loss	$ (5,093)	$ (3,638)
Net loss per share:
Basic (in dollars per share)	$ (0.09)	$ (0.06)
Diluted (in dollars per share)	$ (0.09)	$ (0.06)
Weighted average shares:
Basic (in shares)	58,371	56,190
Diluted (in shares)	58,371	56,190