Note 11 - Income Taxes - Schedule of Effective Income Tax Rate Reconciliation (Details) - USD ($)	12 Months Ended
	Jun. 30, 2022	Jun. 30, 2021
Expected benefit	$ 1,749,000	$ 1,596,000
Tax credits	166,000	187,000
Change in valuation allowance	(1,511,000)	(1,352,000)
Loan forgiveness - PPP loan	0	114,000
Stock-based compensation	(306,000)	(36,000)
Prior year true-up	(9,000)	26,000
Expiration of net operating loss carryovers	(89,000)	(533,000)
Other permanent items	0	(2,000)
Income tax benefit	$ 0	$ 0