Note 8 - Equity Transactions and Stock-based Compensation - Summary of the Company's Stock Option Activity, and Related Information (Details)	9 Months Ended
	Mar. 31, 2023 $ / shares shares
Balance (in shares) | shares	4,443,933
Balance, weighted average exercise price (in dollars per share) | $ / shares	$ 0.36
Granted (in shares) | shares	527,000
Granted (in dollars per share) | $ / shares	$ 0.42
Exercised (in shares) | shares	0
Exercised (in dollars per share) | $ / shares	$ 0
Terminated (in shares) | shares	(591,949)
Terminated (in dollars per share) | $ / shares	$ 0.46
Balance (in shares) | shares	4,378,984
Balance (in dollars per share) | $ / shares	$ 0.35
Exercisable at March 31, 2023 (in shares) | shares	3,576,550
Exercisable at March 31, 2023 (in dollars per share) | $ / shares	$ 0.30