Note 5 - Stockholders' Equity (Deficit) - Outstanding Stock Option (Details) - $ / shares	12 Months Ended
	Sep. 30, 2022	Sep. 30, 2021
Options, Outstanding at beginning of year (in shares)	1,853,479	1,707,515
Weighted Average Exercise Price, Outstanding Balance (in dollars per share)	$ 4.44	$ 5.09
Non-vested options, granted (in shares)	890,750	578,467
Weighted Average Exercise Price, Granted (in dollars per share)	$ 3.17	$ 3.42
Options, Exercised (in shares)	(166,098)	(127,555)
Weighted Average Exercise Price, Exercised (in dollars per share)	$ 1.98	$ 2.14
Options, Forfeited, cancelled, and expired (in shares)	(482,593)	(304,948)
Weighted Average Exercise Price,Forfeited and cancelled (in dollars per share)	$ 5.99	$ 6.89
Options, Outstanding at end of year (in shares)	2,095,538	1,853,479
Weighted Average Exercise Price, Outstanding Balance (in dollars per share)	$ 3.74	$ 4.44
Options, Exercisable at end of year (in shares)	1,163,820	1,269,854
Weighted Average Exercise Price, Exercisable (in dollars per share)	$ 4.15
Weighted-Average Grant Date Fair Value, Non-vested granted (in dollars per share)	$ 1.48	$ 1.57