(8) Income Taxes - Deferred tax assets (Details) - USD ($)	Dec. 30, 2017	Dec. 31, 2016
Deferred Tax Assets:
Net operating loss carryforwards	$ 634,000	$ 363,000
Stock compensation	478,000	628,000
Credit carryforwards	1,494,000	1,265,000
Inventory	235,000	369,000
Accrued liabilities	20,000	27,000
Depreciation	175,000	171,000
Other	3,000	4,000
Gross deferred tax assets	3,039,000	2,827,000
Valuation allowance
Net deferred tax assets	$ 3,039,000	$ 2,827,000