Consolidated Statements of Stockholders' Equity - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	AOCI Attributable to Parent [Member]	Total
Balance (in shares) at Dec. 30, 2018	6,823
Balance at Dec. 30, 2018	$ 7	$ 285,062	$ (267,814)	$ 17,255
Common stock issued under stock plans and employee stock purchase plans (in shares)	110
Common stock issued under stock plans and employee stock purchase plans	$ 0	(37)	0	(37)
Common stock offering, net of issuance costs (in shares)	1,314
Common stock offering, net of issuance costs	$ 1	8,001	0	8,002
Common stock issued for SensiML acquisition (in shares)	84
Common stock issued for SensiML acquisition	$ 0	903	0	903
Stock-based compensation	0	3,144	0	3,144
Net loss	$ 0	0	(15,444)	(15,444)
Balance (in shares) at Dec. 29, 2019	8,331
Balance at Dec. 29, 2019	$ 8	297,073	(283,258)	13,823
Common stock issued under stock plans and employee stock purchase plans (in shares)	121
Common stock issued under stock plans and employee stock purchase plans	$ 0	(24)	0	(24)
Common stock offering, net of issuance costs (in shares)	2,642
Common stock offering, net of issuance costs	$ 3	8,097	0	8,100
Common stock issued for SensiML acquisition (in shares)	0
Common stock issued for SensiML acquisition	$ 0	0	0	0
Stock-based compensation	0	1,739	0	1,739
Net loss	$ 0	0	(11,151)	(11,151)
Balance (in shares) at Jan. 03, 2021	11,094
Balance at Jan. 03, 2021	$ 11	306,885	(294,409)	12,487
Common stock issued under stock plans and employee stock purchase plans (in shares)	571
Common stock issued under stock plans and employee stock purchase plans	$ 0	(222)	0	(222)
Common stock offering, net of issuance costs (in shares)	198
Common stock offering, net of issuance costs	$ 1	1,033	0	1,034
Stock-based compensation	0	2,526		2,526
Net loss	$ 0	0	(6,616)	(6,616)
Balance (in shares) at Jan. 02, 2022	11,863
Balance at Jan. 02, 2022	$ 12	$ 310,222	$ (301,025)	$ 9,209