Note 15 - Quarterly Financial Data (Details) - USD ($) $ in Thousands	3 Months Ended	6 Months Ended
Dec. 31, 2015	Jul. 04, 2015	Apr. 04, 2015	Dec. 31, 2014	Sep. 27, 2014	Jun. 28, 2014	Mar. 29, 2014	Oct. 03, 2015
Segment revenue	$ 12,287	$ 15,796	$ 18,446	$ 20,879	$ 18,871	$ 23,261	$ 23,271	$ 12,123
Cost of sales	10,223	12,823	14,438	17,139	16,038	22,616	21,000	10,495
Gross profit	2,064	2,973	4,008	3,740	2,833	645	2,271	1,628
Research and development expenses	4,689	5,063	5,211	5,270	5,600	7,262	8,576	4,695
Selling and administrative expense	$ 3,078	3,520	$ 3,803	3,640	3,792	4,536	5,126	$ 3,080
Restructuring Charges		561		133	105	4,409	1,451
Operating loss	$ (5,703)	$ (6,171)	$ (5,006)	$ (5,303)	(6,664)	(15,562)	(12,882)	$ (6,147)
Interest income					1	1	5
Interest expense	$ (28)	$ (19)	$ (16)	$ (134)	(76)	(60)	(33)	$ (20)
Other income, net	(399)	10	(3)		70	587	1,160	12
Net loss	$ (6,130)	$ (6,180)	$ (5,025)	$ (5,437)	$ (6,669)	$ (15,034)	$ (11,750)	$ (6,155)
Basic (in dollars per share)	$ (0.07)	$ (0.07)	$ (0.06)	$ (0.06)	$ (0.08)	$ (0.18)	$ (0.14)	$ (0.07)
Diluted (in dollars per share)	$ (0.07)	$ (0.07)	$ (0.06)	$ (0.06)	$ (0.08)	$ (0.18)	$ (0.14)	$ (0.07)

Total costs related to goods produced and sold during the reporting period.

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The amount of net income (loss) for the period available to each share of common stock or common unit outstanding during the reporting period and to each share or unit that would have been outstanding assuming the issuance of common shares or units for all dilutive potential common shares or units outstanding during the reporting period.

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The net amount of other income and expense amounts, the components of which are not separately disclosed on the income statement, resulting from ancillary business-related activities (that is, excluding major activities considered part of the normal operations of the business) also known as other nonoperating income (expense) recognized for the period. Such amounts may include: (a) dividends, (b) interest on securities, (c) net gains or losses on securities, (d) unusual costs, (e) gains or losses on foreign exchange transactions, and (f) miscellaneous other income and expense items.

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The aggregate costs incurred (1) in a planned search or critical investigation aimed at discovery of new knowledge with the hope that such knowledge will be useful in developing a new product or service, a new process or technique, or in bringing about a significant improvement to an existing product or process; or (2) to translate research findings or other knowledge into a plan or design for a new product or process or for a significant improvement to an existing product or process whether intended for sale or the entity's use, during the reporting period charged to research and development projects, including the costs of developing computer software up to the point in time of achieving technological feasibility, and costs allocated in accounting for a business combination to in-process projects deemed to have no alternative future use.

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Amount of expenses associated with exit or disposal activities pursuant to an authorized plan. Excludes expenses related to a discontinued operation or an asset retirement obligation.

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Total revenue from sale of goods and services rendered during the reporting period, in the normal course of business, reduced by sales returns and allowances, and sales discounts.

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The aggregate total costs related to selling a firm's product and services, as well as all other general and administrative expenses. Direct selling expenses (for example, credit, warranty, and advertising) are expenses that can be directly linked to the sale of specific products. Indirect selling expenses are expenses that cannot be directly linked to the sale of specific products, for example telephone expenses, Internet, and postal charges. General and administrative expenses include salaries of non-sales personnel, rent, utilities, communication, etc.

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