Note 17 - Quarterly Results of Operations (Unaudited) - Summary of Quarterly Results of Operations (Details) - USD ($)	3 Months Ended												12 Months Ended
	Sep. 30, 2019	Jun. 30, 2019	Mar. 31, 2019	Dec. 31, 2018	Sep. 30, 2018	Jun. 30, 2018	Mar. 31, 2018	Dec. 31, 2017	Sep. 30, 2017	Jun. 30, 2017	Mar. 31, 2017	Dec. 31, 2016	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2017
Sales	$ 6,810,097	$ 12,889,939	$ 17,559,315	$ 17,858,946	$ 6,458,360	$ 7,004,431	$ 7,674,997	$ 6,335,494	$ 5,521,002	$ 6,297,791	$ 6,952,487	$ 7,136,291
Gross profit	1,723,389	2,272,035	3,310,635	1,786,463	2,180,028	1,805,683	1,993,351	1,438,153	1,623,287	2,009,370	1,881,439	1,558,142	$ 9,092,522	$ 7,417,215	$ 7,072,238
Loss from continuing operations	$ (1,203,311)	$ (1,211,158)	$ (58,196)	$ (1,562,434)	$ (886,775)	$ (761,380)	$ (348,713)	$ (3,786,829)	$ (598,562)	$ (418,360)	$ (565,985)	$ (872,838)	$ (4,035,099)	$ (5,783,697)	$ (2,455,745)
Basic loss from continuing operations per common share (in dollars per share)	$ (0.12)	$ (0.12)	$ 0	$ (0.15)	$ (0.09)	$ (0.07)	$ (0.03)	$ (0.37)	$ (0.06)	$ (0.04)	$ (0.06)	$ (0.08)	$ (0.39)	$ (0.56)	$ (0.24)
Diluted loss from continuing operations per common share (in dollars per share)	$ (0.12)	$ (0.12)	$ 0	$ (0.15)	$ (0.09)	$ (0.07)	$ (0.03)	$ (0.37)	$ (0.06)	$ (0.04)	$ (0.06)	$ (0.08)	$ (0.12)	$ (0.15)	$ 0.23