Condensed Consolidated Balance Sheets (Current Period Unaudited) (USD $) In Thousands, unless otherwise specified	Mar. 31, 2015	Dec. 31, 2014
Current assets:
Cash and cash equivalents	$ 8,869	$ 7,531
Trade accounts receivable less allowances of $296 and $323, respectively	3,126	3,113
Inventories, net	10,826	7,283
Prepaid and other current assets	991	1,002
Total current assets	23,812	18,929
Property and equipment, net	539	479
Other assets	86	88
Total assets	24,437	19,496
Current liabilities:
Accounts payable	7,061	7,601
Accrued liabilities	1,215	1,209
Accrued warranty reserve	503	188
Deferred revenue	236	133
Billings in excess of costs and estimated earnings on uncompleted contracts		23
Credit line borrowings	1,726	453
Total current liabilities	10,741	9,607
Other liabilities	89	46
Long-term debt	70	70
Total liabilities	10,900	9,723
Preferred stock, par value $0.0001 per share:
Issued and outstanding: no shares in 2015 and 2014	0	0
Common stock, par value $0.0001 per share:
9,423,975 at December 31, 2014	1	1
Additional paid-in capital	100,741	98,133
Accumulated other comprehensive income	496	469
Accumulated deficit	(87,701)	(88,830)
Total stockholders' equity	13,537	9,773
Total liabilities and stockholders' equity	$ 24,437	$ 19,496