Note 14 - Income Taxes - Reconciliation of Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Sep. 30, 2021	Sep. 30, 2020
Income taxes computed at the federal statutory rate	$ 239	$ 1,296
Change in valuation allowance	435	(7,134)
Nondeductible compensation, interest expense and other	57	24
State income taxes, net of federal tax benefit	210	364
Change in R&D credit carryover	19	(219)
Stock options and other prior year true-ups	(175)	(7)
Foreign rate differential	(117)	(21)
State business credit utilization	(234)	(9)
Provision (benefit) for income taxes	$ 434	$ (5,706)