CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 29, 2019	Dec. 30, 2018	Dec. 31, 2017
Cash flows from operating activities:
Net loss	$ (15,444,000)	$ (13,779,000)	$ (14,131,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,201,000	1,276,000	1,373,000
Stock-based compensation	3,144,000	1,901,000	1,441,000
Write-down of inventories	94,000	386,000	232,000
Write-off of equipment	4,000	5,000	12,000
Tax benefit from acquisition	(185,000)
Gain on disposal of assets		(62,000)
Changes in operating assets and liabilities:
Accounts receivable	218,000	(1,284,000)	(86,000)
Inventories	483,000	(662,000)	(1,774,000)
Other assets	229,000	(879,000)	103,000
Trade payables	(456,000)	223,000	(145,000)
Accrued liabilities	(1,024,000)	235,000	72,000
Deferred income	158,000
Other long-term liabilities	(16,000)	2,000	(35,000)
Net cash used in operating activities	(11,594,000)	(12,638,000)	(12,938,000)
Cash flows from investing activities:
Capital expenditures for property and equipment	(576,000)	(351,000)	(642,000)
Capitalized internal-use software	(365,000)
Cash received from business acquisition	20,000
Proceeds from sale of assets		63,000
Net cash used in investing activities	(921,000)	(288,000)	(642,000)
Cash flows from financing activities:
Payment of finance lease obligations	(365,000)	(407,000)	(344,000)
Proceeds from line of credit	46,000,000	36,000,000	18,000,000
Repayment of line of credit	(46,000,000)	(27,000,000)	(18,000,000)
Proceeds from issuance of common stock	9,437,000	16,215,000	17,550,000
Stock issuance costs	(1,181,000)	(1,638,000)	(1,771,000)
Taxes paid related to net settlement of equity awards	(291,000)	(308,000)	(198,000)
Net cash provided by financing activities	7,600,000	22,862,000	15,237,000
Net (decrease) increase in cash, cash equivalents and restricted cash	(4,915,000)	9,936,000	1,657,000
Cash, cash equivalents and restricted cash at the beginning of the period	26,463,000	16,527,000	14,870,000
Cash, cash equivalents, and restricted cash at the end of the period	21,548,000	26,463,000	16,527,000
Supplemental disclosures of cash flow information:
Interest paid	300,000	89,000	106,000
Income taxes paid	126,000	171,000	157,000
Supplemental schedule of non-cash investing and financing activities :
Fair value of common stock issued as consideration for business acquisition	903,000
Finance lease obligation to finance capital expenditures	$ 471,000	424,000	654,000
Purchase of equipment included in accounts payable		$ 5,000	$ 436,000