Unaudited Condensed Consolidated Statements of Stockholders' Equity (Unaudited) - USD ($) shares in Thousands, $ in Thousands	Common Stock [Member]	Additional Paid-in Capital [Member]	Retained Earnings [Member]	Total
Balance (in shares) at Jan. 02, 2022	11,863
Balance at Jan. 02, 2022	$ 12	$ 310,222	$ (301,025)	$ 9,209
Issuance of common stock under public stock offering, net of stock issuance cost (in shares)	310
Issuance of common stock under public stock offering, net of stock issuance cost	$ 0	1,482	0	1,482
Common stock issued under stock plans and employee stock purchase plans (in shares)	189
Common stock issued under stock plans and employee stock purchase plans	$ 0	383	0	383
Net loss	0	0	(1,164)	(1,164)
Net loss	$ 0	0	(1,164)	(1,164)
Balance (in shares) at Apr. 03, 2022	12,362
Balance at Apr. 03, 2022	$ 12	312,087	(302,189)	9,910
Balance (in shares) at Jan. 02, 2022	11,863
Balance at Jan. 02, 2022	$ 12	310,222	(301,025)	9,209
Net loss				(1,688)
Net loss				(1,688)
Balance (in shares) at Jul. 03, 2022	12,428
Balance at Jul. 03, 2022	$ 12	312,686	(302,713)	9,985
Balance (in shares) at Apr. 03, 2022	12,362
Balance at Apr. 03, 2022	$ 12	312,087	(302,189)	9,910
Common stock issued under stock plans and employee stock purchase plans (in shares)	66
Common stock issued under stock plans and employee stock purchase plans	$ 0	122	0	122
Stock-based compensation	0	477	0	477
Net loss	0	0	(524)	(524)
Net loss	$ 0	0	(524)	(524)
Balance (in shares) at Jul. 03, 2022	12,428
Balance at Jul. 03, 2022	$ 12	312,686	(302,713)	9,985
Balance (in shares) at Jan. 01, 2023	13,202
Balance at Jan. 01, 2023	$ 13	317,174	(305,292)	11,895
Issuance of common stock under public stock offering, net of stock issuance cost (in shares)	450
Issuance of common stock under public stock offering, net of stock issuance cost	$ 1	2,292	0	2,293
Common stock issued under stock plans and employee stock purchase plans (in shares)	34
Common stock issued under stock plans and employee stock purchase plans	$ 0	0	0	0
Stock-based compensation	0	715	0	715
Net loss			(1,228)	(1,228)
Net loss			(1,228)	(1,228)
Balance (in shares) at Apr. 02, 2023	13,686
Balance at Apr. 02, 2023	$ 14	320,181	(306,520)	13,675
Balance (in shares) at Jan. 01, 2023	13,202
Balance at Jan. 01, 2023	$ 13	317,174	(305,292)	11,895
Net loss				(3,497)
Net loss				(3,497)
Balance (in shares) at Jul. 02, 2023	13,725
Balance at Jul. 02, 2023	$ 14	320,950	(308,789)	12,175
Balance (in shares) at Apr. 02, 2023	13,686
Balance at Apr. 02, 2023	$ 14	320,181	(306,520)	13,675
Common stock issued under stock plans and employee stock purchase plans (in shares)	39
Common stock issued under stock plans and employee stock purchase plans	$ 0	122	0	122
Stock-based compensation	0	647	0	647
Net loss	0	0	(2,269)	(2,269)
Net loss	$ 0	0	(2,269)	(2,269)
Balance (in shares) at Jul. 02, 2023	13,725
Balance at Jul. 02, 2023	$ 14	$ 320,950	$ (308,789)	$ 12,175