Note 13 - Stock-based Compensation - Schedule of Allocation of Recognized Period Cost (Details) - USD ($) $ in Thousands	12 Months Ended
	Jan. 03, 2021	Dec. 29, 2019	Dec. 30, 2018
Total costs and expenses	$ 1,739	$ 3,144	$ 1,901
Cost of Sales [Member]
Total costs and expenses	162	78	129
Research and Development Expense [Member]
Total costs and expenses	670	2,242	760
Selling, General and Administrative Expenses [Member]
Total costs and expenses	$ 907	$ 824	$ 1,012