Note 5 - Stockholders' Equity (Deficit) - Outstanding Stock Option (Details) - $ / shares	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019
Options, Outstanding at beginning of year (in shares)	1,654,429	2,029,741
Weighted Average Exercise Price, Outstanding Balance (in dollars per share)	$ 5.62	$ 7.04
Non-vested options, granted (in shares)	228,750	229,350
Weighted Average Exercise Price, Granted (in dollars per share)	$ 1.86	$ 0.73
Options, Exercised (in shares)	(37,998)
Weighted Average Exercise Price, Exercised (in dollars per share)	$ 1.53
Options, Forfeited (in shares)	(137,666)	(604,662)
Weighted Average Exercise Price, Forfeited (in dollars per share)	$ 6.82	$ 8.53
Options, Outstanding at end of year (in shares)	1,707,515	1,654,429
Weighted Average Exercise Price, Outstanding Balance (in dollars per share)	$ 5.09	$ 5.62
Options, Exercisable at end of year (in shares)	1,367,618	1,297,315
Weighted-Average Grant Date Fair Value, Non-vested granted (in dollars per share)	$ 0.84	$ 0.28