Condensed Consolidated Statements of Operations (Unaudited) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2019	Sep. 30, 2018	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 9,613	$ 8,667	$ 21,809	$ 22,190
Cost of revenue	4,874	4,220	10,862	10,513
Gross profit	4,739	4,447	10,947	11,677
Operating expenses
Research and development	1,686	1,704	4,762	5,493
Selling, general and administrative	1,442	1,899	4,939	5,092
Total operating expenses	3,128	3,603	9,701	10,585
Income from operations	1,611	844	1,246	1,092
Other income (expense)	2	(94)	41	130
Income before income taxes	1,613	750	1,287	1,222
Income tax provision (benefits)	156	186	113	(16)
Net income	$ 1,457	$ 564	$ 1,174	$ 1,238
Net income per share:
Basic	$ 0.08	$ 0.03	$ 0.07	$ 0.07
Diluted	$ 0.08	$ 0.03	$ 0.07	$ 0.07
Weighted average shares outstanding in computing net income per share
Basic	17,316,172	17,045,689	17,239,544	16,936,898
Diluted	17,899,140	17,922,635	17,850,360	18,039,404