CONSOLIDATED STATEMENTS OF CASH FLOWS - USD ($)	12 Months Ended
	Dec. 30, 2018	Dec. 31, 2017	Jan. 01, 2017
Cash flows from operating activities:
Net loss	$ (13,779,000)	$ (14,131,000)	$ (19,148,000)
Adjustments to reconcile net loss to net cash used in operating activities:
Depreciation and amortization	1,276,000	1,373,000	1,332,000
Stock-based compensation	1,901,000	1,441,000	1,584,000
Write-down of inventories	386,000	232,000	296,000
Write-off of equipment	5,000	12,000	368,000
Gain on disposal of assets	(62,000)
Changes in operating assets and liabilities:
Accounts receivable	(1,284,000)	(86,000)	762,000
Inventories	(662,000)	(1,774,000)	565,000
Other assets	(879,000)	103,000	305,000
Trade payables	223,000	(145,000)	(1,337,000)
Accrued liabilities	235,000	72,000	124,000
Deferred income			(26,000)
Other long-term liabilities	2,000	(35,000)	(84,000)
Net cash used in operating activities	(12,638,000)	(12,938,000)	(15,259,000)
Cash flows from investing activities:
Capital expenditures for property and equipment	(351,000)	(642,000)	(1,954,000)
Proceeds on sale of assets	63,000
Net cash used in investing activities	(288,000)	(642,000)	(1,954,000)
Cash flows from financing activities:
Payment of capital software lease obligations	(407,000)	(344,000)	(280,000)
Proceeds from line of credit	36,000,000	18,000,000	4,000,000
Repayment of line of credit	(27,000,000)	(18,000,000)
Proceeds from issuance of common stock	16,215,000	17,550,000	10,603,000
Stock issuance costs	(1,638,000)	(1,771,000)	(1,197,000)
Taxes paid related to net settlement of equity awards	(308,000)	(198,000)	(179,000)
Net cash provided by financing activities	22,862,000	15,237,000	12,947,000
Net increase (decrease) in cash, cash equivalents and restricted cash	9,936,000	1,657,000	(4,266,000)
Cash, cash equivalents and restricted cash at the beginning of the period	16,527,000	14,870,000	19,136,000
Cash, cash equivalents, and restricted cash at the end of the period	26,463,000	16,527,000	14,870,000
Supplemental disclosures of cash flow information:
Interest paid	89,000	106,000	183,000
Income taxes paid	171,000	157,000	128,000
Supplemental schedule of non-cash investing and financing activities :
Capital software lease obligation to finance capital expenditures	424,000	654,000	$ 209,000
Purchase of equipment included in accounts payable	$ 5,000	$ 436,000