Note 9 - Equity - Warrant Activity (Details) - $ / shares	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2020
Outstanding, warrants (in shares)	11,238,650	9,478,650
Outstanding, warrants, weighted average exercise price (in dollars per share)	$ 1.52	$ 1.55
Outstanding, warrants, weighted average remaining contract term (Year)	1 year 292 days	2 years 109 days	2 years 219 days
Granted, warrants (in shares)		2,148,000
Granted, warrants, weighted average exercise price (in dollars per share)		$ 1.33
Exercised, warrants (in shares)	(1,600,000)	(388,000)
Exercised, warrants, weighted average exercise price (in dollars per share)		$ 1.23
Expired, warrants, weighted average exercise price (in dollars per share)	$ 2.25
Outstanding, warrants (in shares)	11,238,650	9,478,650	9,478,650	9,638,650
Outstanding, warrants, weighted average exercise price (in dollars per share)	$ 1.52	$ 1.55	$ 1.55	$ 1.39
Exercisable, warrants (in shares)	9,638,650
Exercisable, warrants, weighted average exercise price (in dollars per share)	$ 1.39
Exercisable, warrants, weighted average remaining contract term (Year)	1 year 182 days