Note 7 - Shareholders' Equity - Stock-based Compensation Expense (Details) - USD ($) $ in Thousands	3 Months Ended	9 Months Ended
Sep. 30, 2021	Sep. 30, 2020	Sep. 30, 2021	Sep. 30, 2020
Total stock-based compensation expense	$ 218	$ 281	$ 596	$ 601
Cost of Sales [Member] \| Edge to Cloud [Member]
Total stock-based compensation expense	6	26	30	50
Selling, General and Administrative Expenses [Member]
Total stock-based compensation expense	188	250	515	536
Research and Development Expense [Member]
Total stock-based compensation expense	$ 24	$ 5	$ 51	$ 15

Amount of expense for award under share-based payment arrangement. Excludes amount capitalized.

Reference 1: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 2: http://fasb.org/us-gaap/role/ref/legacyRef
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Reference 3: http://fasb.org/us-gaap/role/ref/legacyRef
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