CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2021	Jun. 30, 2020
Operating activities
Net income (loss)	$ 1,002	$ (1,494)
Adjustments to reconcile net income (loss) to net cash (used in) provided by operating activities:
Inventories allowances	368	72
Deferred tax expense	184	28
Depreciation and amortization	681	661
Share-based compensation expense-stock options	65	60
Share-based compensation expense-restricted stock units	128	89
(Gain) loss on investment in securities	(2,467)	506
Changes in operating assets and liabilities:
Trade accounts receivable	(744)	381
Inventories	(2,963)	3,914
Prepaid expenses and other current assets	12	325
Other assets	11	54
ROU asset and lease liability	(8)	44
Accounts payable	1,197	(838)
Accrued compensation and related taxes	(154)	(331)
Accrued warranty expense	(147)	(337)
Deferred revenue	(47)	557
Accrued other expenses and other current liabilities	57	(94)
Net cash (used in) provided by operating activities	(2,825)	3,597
Investing activities
Purchases of property, plant, and equipment	(1,541)	(525)
Net cash used in investing activities	(1,541)	(525)
Financing activities
Proceeds from common stock issuance, net of costs	11,599	0
Cash dividends paid	(501)	(502)
Repurchase of common stock	0	(269)
Proceeds from the credit facility and notes payable	3,543	2,196
Repayment of the credit facility and notes payable	(1,400)	(2,234)
Net cash provided by (used in) financing activities	13,201	(809)
Net change in cash and cash equivalents	8,835	2,263
Cash and cash equivalents, beginning of period	6,826	4,676
Cash and cash equivalents, end of period	15,661	6,939
Supplemental disclosure
Cash paid for interest	14	11
Non-cash financing activity
Common stock issued under restricted stock units	$ 84	$ 56