UNAUDITED CONDENSED CONSOLIDATED STATEMENTS OF OPERATIONS - USD ($) shares in Thousands, $ in Thousands		3 Months Ended
		Mar. 29, 2020	Mar. 31, 2019
Income Statement [Abstract]
Revenue		$ 2,158	$ 3,194
Cost of revenue		1,043	1,215
Gross profit		1,115	1,979
Operating expenses:
Research and development		1,819	3,242
Selling, general and administrative		1,879	2,446
Restructuring costs		479
Total operating expenses		4,177	5,688
Loss from operations		(3,062)	(3,709)
Interest expense		(80)	(83)
Interest income and other (expense), net		(5)	48
Loss before income taxes		(3,147)	(3,744)
Provision for (benefit from) income taxes		18	(268)
Net loss		$ (3,165)	$ (3,476)
Net loss per share:
Basic and diluted	[1]	$ (0.38)	$ (0.50)
Weighted average shares outstanding:
Basic and diluted	[1]	8,362	6,916

[1] Net loss per share, and weighted average shares outstanding basic and diluted are adjusted to reflect 1-for-14 reverse stock split effected on December 23, 2019.