Consolidated Balance Sheets (Parentheticals) - USD ($) $ in Thousands	Sep. 30, 2020	Sep. 30, 2019
Statement of Financial Position [Abstract]
Accounts receivable, allowance for credit loss, current	$ 250	$ 150
Inventory valuation reserves	$ 3,054	$ 1,275
Common stock, par or stated value per share (in dollars per share)	$ 0.01	$ 0.01
Common stock, shares authorized (in shares)	30,000,000	30,000,000
Common stock issuance (in shares)	11,822,009	10,861,950
Common stock, shares, outstanding (in shares)	11,822,009	10,361,292
Treasury stock, shares (in shares)	0	500,658
Other current liabilities	$ 41	$ 758
Total current liabilities	$ 11,194	$ 7,204