Note 17 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($)	Mar. 31, 2016	Mar. 31, 2015
Inventory reserves	$ 504,000	$ 115,000
Accrued vacation	439,000	244,000
Stock option compensation	141,000	47,000
Warranty reserve	74,000	85,000
Accounts and notes receivable reserve	181,000	83,000
Net operating loss carryforwards	5,353,000
Federal credits	4,784,000
263A inventory capitalization	60,000	145,000
Other	112,000	79,000
Total deferred tax assets	11,648,000	798,000
Deferred Revenue	(52,000)
Prepaid expenses	(563,000)	(473,000)
Property and equipment	(70,000)	(463,000)
Intangibles	(388,000)
Total deferred tax liabilities	(1,073,000)	(936,000)
Net deferred tax (liability) asset	10,575,000	(138,000)
Less Valuation Allowance	(10,830,000)
Net deferred tax (liability) asset after Valuation Allowance	$ (255,000)	$ (138,000)