Note 10 - Stock-based Compensation (Tables)

3 Months Ended

Mar. 31, 2021

Notes Tables

Share-based Payment Arrangement, Expensed and Capitalized, Amount [Table Text Block]

	Three Months Ended March 31,
	2021		2020
Cost of revenues	$	-	$	-
Selling expense		3		3
Engineering and product development expense		10		10
General and administrative expense		256		174
	$	269	$	187

Schedule of Nonvested Share Activity [Table Text Block]

	Number of Shares			Weighted Average Grant Date Fair Value
Unvested shares outstanding, January 1, 2021		237,155		$	4.93
Granted		81,468			10.62
Vested		(22,200	)		8.56
Forfeited		-			-
Unvested shares outstanding, March 31, 2021		296,423			6.22

Schedule of Share-based Payment Award, Stock Options, Valuation Assumptions [Table Text Block]

	2021			2020
Risk-free interest rate		1.00	%		0.48	%
Dividend yield		0.00	%		0.00	%
Expected common stock market price volatility factor		.49			.43
Weighted average expected life of stock options (years)		6.25			6.25

Share-based Payment Arrangement, Option, Activity [Table Text Block]

	Number of Shares			Weighted Average Grant Date Fair Value
Options outstanding, January 1, 2021 (204,630 exercisable)		438,200		$	6.25
Granted		164,800			10.62
Exercised		(99,740	)		7.19
Forfeited		-			-
Options outstanding, March 31, 2021 (144,265 exercisable)		503,260			7.49