Note 11 - Income Taxes - Schedule of Deferred Tax Assets and Liabilities (Details) - USD ($) $ in Thousands	Jun. 30, 2022	Jun. 30, 2021
Deferred tax assets:
Net operating loss carryforwards	$ 17,202	$ 15,882
Tax credit carryforwards	1,330	1,165
Lease liability - current and non-current	113	62
Accrued expenses and other timing	180	65
Stock-based compensation	579	676
Property and equipment, principally due to differences in depreciation	0	77
Total gross deferred tax assets	19,404	17,927
Less — valuation allowance	(19,348)	(17,875)
Net deferred tax assets	56	52
Deferred tax liabilities:
Right-of-use assets	(34)	(52)
Property and equipment, principally due to differences in depreciation	(22)	0
Total gross deferred tax liabilities	(56)	(52)
Net deferred tax assets	$ 0	$ 0