2. STOCK-BASED COMPENSATION (Details Narrative) - USD ($) $ / shares in Units, $ in Thousands	3 Months Ended			6 Months Ended
	Nov. 30, 2016	Aug. 31, 2016	Nov. 30, 2015	Nov. 30, 2016	Nov. 30, 2015
Stock-based compensation costs capitalized as part of inventory	$ 0		$ 0	$ 0	$ 0
Intrinsic value of options exercised	359		125	$ 411	185
Weighted average remaining contractual life of the options exercisable and expected to be exercisable				4 years 29 days
2006 and 2016 Equity Incentive Plans
Unrecognized stock-based compensation	1,266			$ 1,266
Estimated forfeitures of unvested stock based awards, amount	3			$ 3
Weighted average period for recognition of costs				2 years 4 months 24 days
Employee Stock Purchase Plan
Stock-based compensation related to the ESPP	30		$ 21	$ 70	$ 55
Compensation cost related to purchase rights under the ESPP but not yet recognized	$ 72			$ 72
Weighted average period for recognition of costs				10 months 24 days
ESPP purchase right granted	0		0	0	0
RSU Transactions
Restricted Stock Units granted (in thousands)	0			138
Market value on the date of the grant				$ 1.68
Stock Option and RSU Transactions
Shares reserved under 2016 Equity Incentive plan (in thousands)	2,238
Stock-based compensation expense related to stock options and RSUs	$ 185		$ 233	$ 464	$ 518
Restricted Stock Units granted (in thousands)	0	138