Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	9 Months Ended
	Sep. 26, 2020	Sep. 28, 2019
Operating activities:
Net loss	$ (6,150)	$ (7,252)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	399	534
Change in fair value of earn-out liability		47
Stock-based compensation	774	1,398
Provision for doubtful accounts	138	25
Loss on sale of property and equipment	13
Changes in operating assets and liabilities:
Accounts receivable	3,110	265
Inventories	1,155	(188)
Prepaid expenses and other current assets	(141)	(43)
Operating lease right-of-use assets	1,073	922
Other long-term assets	5	11
Accounts payable	(1,117)	(86)
Accrued compensation	(510)	(1,015)
Accrued expenses	135	(726)
Accrued warranty	(252)	(347)
Deferred revenue	(452)	(331)
Operating lease liabilities	(1,209)	(938)
Net cash used in operating activities	(3,029)	(7,724)
Investing activities:
Acquisition of property and equipment	(87)	(125)
Payment on earn-out liability		(318)
Proceeds from sale of property and equipment	3
Net cash used in investing activities	(84)	(443)
Financing activities:
Proceeds from PPP loan	2,497
Taxes paid related to net share settlements of equity awards	(29)	(151)
Net cash provided by (used in) financing activities	2,468	(151)
Effect of foreign exchange rate changes	(76)	72
Net decrease in cash and cash equivalents	(721)	(8,246)
Cash and cash equivalents, beginning of period	12,653	21,194
Cash and cash equivalents, end of period	11,932	12,948
Supplemental disclosure of cash flow information:
Cash (received) paid during the period for income taxes	(25)	19
Supplemental disclosure of non-cash activities:
Transfer of inventory to property and equipment	$ 36	$ 65