Note 10 - Income Taxes - Effective Tax Rate Reconciliation (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 29, 2024	Dec. 31, 2023	Jan. 01, 2023
Income tax benefit at statutory rate, amount	$ (806)	$ (55)	$ (876)
Income tax benefit at statutory rate, percent	21.00%	21.00%	21.00%
State taxes, amount	$ (2)	$ 9	$ 3
State taxes, percent	0.10%	(3.40%)	(0.10%)
Foreign taxes, amount	$ 17	$ 0	$ 106
Foreign taxes, percent	(0.40%)	(0.10%)	(2.50%)
Stock compensation and other permanent differences, amount	$ 8	$ (740)	$ 21
Stock compensation and other permanent differences	(0.20%)	282.90%	(0.50%)
162(m), amount	$ 147	$ 0	$ 0
162(m), percent	(3.80%)	0.00%	0.00%
R&D tax credits	$ (543)	$ (480)	$ (318)
R&D tax credits	14.10%	183.80%	7.60%
Expired tax attributes, amount	$ 585	$ 1,290	$ 3,563
Expired tax attributes, percent	(15.30%)	(493.50%)	(85.50%)
Future benefit of deferred tax assets not recognized, amount	$ 597	$ (22)	$ (2,401)
Future benefit of deferred tax assets not recognized, percent	(15.60%)	8.60%	57.60%
Provision for income taxes, amount	$ 3	$ 2	$ 98
Provision for income taxes, percent	(0.10%)	(0.70%)	(2.40%)