Condensed Consolidated Balance Sheets (Current Period Unaudited) - USD ($) $ in Thousands	Sep. 30, 2022	Jun. 30, 2022
Current assets
Cash and cash equivalents	$ 18,273	$ 26,453
Short-term investments	30,675	26,173
Accounts receivable	38	56
Cost and estimated revenue in excess of billings	0	2
Inventory, net:
Raw materials	925	864
Work-in-process	76	136
Finished goods	465	518
Prepaid expenses and other current assets	901	748
Total current assets	51,353	54,950
Property and equipment, net	1,350	1,098
Operating lease assets	140	162
Other assets	11	11
Total assets	52,854	56,221
Current liabilities
Accounts payable	287	169
Payroll related accruals	478	816
Accrued expenses and other liabilities	883	961
Income tax payable	1	2
Term note payable - related party	0	500
Lease liabilities, current	239	234
Total current liabilities	1,888	2,682
Lease liabilities, net of current portion	241	303
Total liabilities	2,129	2,985
Commitments and contingencies (Note 13)
Stockholders’ equity
Convertible preferred stock, $0.001 par value, 2,500,000 shares authorized; 280,898 shares of Series D issued and outstanding at September 30, 2022 and June 30, 2022	0	0
Common stock, $0.001 par value, 250,000,000 shares authorized at September 30, 2022 and June 30, 2022; 50,629,183 and 50,567,864 shares issued and outstanding at September 30, 2022 and June 30, 2022, respectively	190,642	190,642
Additional paid-in capital	79,892	79,505
Accumulated deficit	(218,242)	(215,712)
Accumulated other comprehensive loss	(1,567)	(1,199)
Total stockholders’ equity	50,725	53,236
Total liabilities and stockholders’ equity	$ 52,854	$ 56,221