Condensed Consolidated Statements of Changes in 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	0	0	0
Stock-based compensation	0	383	0	383
Net income (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 income (loss)				(3,035)
Balance (in shares) at Oct. 02, 2022	13,110
Balance at Oct. 02, 2022	$ 13	316,355	(304,060)	12,308
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 income (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
Issuance of common stock under public stock offering, net of stock issuance cost (in shares)	487
Issuance of common stock under public stock offering, net of stock issuance cost	$ 1	3,182	0	3,183
Common stock issued under stock plans and employee stock purchase plans (in shares)	195
Common stock issued under stock plans and employee stock purchase plans	$ 0	0	0	0
Stock-based compensation	0	487	0	487
Net income (loss)	$ 0	0	(1,347)	(1,347)
Balance (in shares) at Oct. 02, 2022	13,110
Balance at Oct. 02, 2022	$ 13	316,355	(304,060)	12,308
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 income (loss)	$ 0	0	(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 income (loss)				(2,305)
Balance (in shares) at Oct. 01, 2023	13,906
Balance at Oct. 01, 2023	$ 14	321,623	(307,597)	14,040
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 income (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
Issuance of common stock under public stock offering, net of stock issuance cost	$ 0	0	0	0
Common stock issued under stock plans and employee stock purchase plans (in shares)	181
Common stock issued under stock plans and employee stock purchase plans	$ 0	0	0	0
Stock-based compensation	0	673	0	673
Net income (loss)	$ 0	0	1,192	1,192
Balance (in shares) at Oct. 01, 2023	13,906
Balance at Oct. 01, 2023	$ 14	$ 321,623	$ (307,597)	$ 14,040