Note 5 - Stockholders' Equity (Deficit) - Outstanding Stock Option (Details) - $ / shares	12 Months Ended
	Sep. 30, 2023	Sep. 30, 2022
Options, Outstanding at beginning of year (in shares)	2,095,538	1,853,479
Weighted Average Exercise Price, Outstanding Balance (in dollars per share)	$ 3.74	$ 4.44
Non-vested options, granted (in shares)	652,850	890,750
Weighted Average Exercise Price, Granted (in dollars per share)	$ 0.84	$ 3.17
Options, Exercised (in shares)	(2,550)	(166,098)
Weighted Average Exercise Price, Exercised (in dollars per share)	$ 0.66	$ 1.98
Options, Forfeited, cancelled, and expired (in shares)	(350,298)	(482,593)
Weighted Average Exercise Price,Forfeited and cancelled (in dollars per share)	$ 3.72	$ 5.99
Options, Outstanding at end of year (in shares)	2,395,540	2,095,538
Weighted Average Exercise Price, Outstanding Balance (in dollars per share)	$ 2.95	$ 3.74
Options, Exercisable at end of year (in shares)	1,533,870	1,163,820
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 3.53	$ 4.15
Weighted-Average Grant Date Fair Value, Non-vested granted (in dollars per share)	$ 0.41	$ 1.48