Condensed Consolidated Statements of Cash Flows (Unaudited) - USD ($) $ in Thousands	3 Months Ended		6 Months Ended
	Jul. 03, 2021	Jun. 27, 2020	Jul. 03, 2021	Jul. 03, 2021	Jun. 27, 2020	Jun. 27, 2020
Operating activities:
Net loss			$ (617)			$ (4,431)
Adjustments to reconcile net loss to net cash provided by (used in) operating activities:
PPP loan forgiveness			(2,497)
Depreciation and amortization			365			277
Stock-based compensation	$ 280	$ 436	646	$ 646	$ 531	531
Provision for doubtful accounts						101
Changes in operating assets and liabilities:
Accounts receivable			(1,312)			3,435
Inventories			(22)			278
Prepaid expenses and other current assets			(181)			(107)
Operating lease right-of-use assets			431			608
Other long-term assets			75			(7)
Accounts payable			1,101			(2,035)
Accrued compensation			103			(845)
Accrued expenses			464			(177)
Accrued warranty			(67)			(162)
Deferred revenue			11,257			(286)
Operating lease liabilities			(524)			(696)
Other liabilities			1,377			77
Net cash provided by (used in) operating activities			10,599			(3,439)
Investing activities:
Acquisition of property and equipment			(125)			(79)
Cash paid for business combination, net			(5,343)
Net cash used in investing activities			(5,468)			(79)
Financing activities:
Proceeds from issuance of common stock, net of issuance costs			9,878
Proceeds from stock option exercise			97
Taxes paid related to net share settlements of equity awards			(518)			(4)
Proceeds from PPP loan						2,497
Net cash provided by financing activities			9,457			2,493
Effect of foreign exchange rate changes			45			(4)
Net increase (decrease) in cash and cash equivalents			14,633			(1,029)
Cash and cash equivalents, beginning of period			11,626			12,653
Cash and cash equivalents, end of period	$ 26,259	$ 11,624	26,259	$ 26,259	$ 11,624	11,624
Supplemental disclosure of cash flow information:
Cash paid during the period for income taxes			23			21
Supplemental disclosure of non-cash activities:
Transfer of inventory to property and equipment			78			$ 49
ROU assets obtained with extension of operating lease			$ 1,824