Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended
	Mar. 31, 2018	Mar. 31, 2017
Cash flows from operating activities:
Net loss	$ (2,390)	$ (4,522)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation	151	177
Stock-based compensation	195	207
Stock-based compensation reversal	0	(269)
Provision for doubtful accounts receivable	(22)	0
Provision for slow-moving and obsolete inventories and valuation reserves	(487)	162
Provision for warranties	(33)	13
(Gain) loss on dispositions of property and equipment	(19)	8
Changes in operating assets and liabilities:
Accounts Receivable	66	3,054
Inventories	597	866
Prepaid and other assets	(274)	(114)
Accounts payable	1,398	(1,649)
Accrued and other liabilities	53	248
Deferred revenue	22	174
Total adjustments	1,647	2,877
Net cash used in operating activities	(743)	(1,645)
Cash flows from investing activities:
Acquisitions of property and equipment	(57)	(29)
Proceeds from the sale of property and equipment	244	0
Net cash provided by (used in) investing activities	187	(29)
Cash flows from financing activities:
Proceeds from exercises of stock options and employee stock purchase plan purchases	0	77
Common stock withheld to satisfy income tax withholding on vesting of restricted stock units	32	47
Net cash (used in) provided by financing activities	(32)	30
Effect of exchange rate changes on cash	(1)	(15)
Net decrease in cash and cash equivalents	(589)	(1,659)
Cash and cash equivalents, beginning of period	10,761	16,629
Cash and cash equivalents, end of period	10,172	14,970
Classification of cash and cash equivalents:
Cash and cash equivalents, end of period	$ 10,761	$ 16,629