Note 2 - Summary of Significant Accounting Policies and Recent Developments (Details Textual)						1 Months Ended	3 Months Ended	12 Months Ended
	Mar. 28, 2023 USD ($) $ / shares shares	Feb. 22, 2023 USD ($) $ / shares shares	Nov. 03, 2022 USD ($) $ / shares shares	Jul. 15, 2022 USD ($) $ / shares	Mar. 18, 2022 USD ($)	Mar. 31, 2022 USD ($)	Mar. 31, 2021 USD ($)	Dec. 31, 2022 USD ($) $ / shares shares	Dec. 31, 2021 USD ($) $ / shares shares	Sep. 22, 2022 USD ($)	Mar. 24, 2022 USD ($)	Mar. 18, 2021 USD ($)	Dec. 31, 2020 $ / shares
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares								$ 3.10	$ 3.57				$ 3.73
Proceeds from Issuance or Sale of Equity, Total								$ 0	$ 9,660,000
Net Income (Loss) Attributable to Parent, Total								(5,575,000)	(8,052,000)
Liabilities, Current, Total								10,241,000	12,532,000
Assets, Current, Total								5,960,000	5,593,000
Working Capital Deficit								4,300,000	6,900,000
Accounts Receivable, Allowance for Credit Loss, Current								150,000	482,000
Accounts Receivable, Credit Loss Expense (Reversal)								(94,000)	268,000
Inventory Write-down								52,000	0
Operating Income (Loss), Total								(8,410,000)	(11,413,000)
Impairment, Long-Lived Asset, Held-for-Use, Total								0
Impairment of Long-Lived Assets to be Disposed of								0	128,000
Goodwill and Intangible Asset Impairment, Total								$ 0	$ 0
Share-based Compensation Arrangement by Share-based Payment Award, Options and Warrants, Outstanding, Number (in shares) | shares								1,760,805	1,193,419
Share-based Compensation Arrangement by Share-based Payment Award, Options and Warrants, Outstanding, Aggregate Intrinsic Value									$ 0
Adjustments to Additional Paid in Capital, Stock Issued, Issuance Costs								$ 0	815,000
Employee Retention Tax Credit, Maximum Amount Per Employee Per Quarter							$ 7,000
Employee Retention Tax Credit								0	$ 1,800,000
Payments of Dividends, Total								$ 0
Domestic Tax Authority [Member]
Open Tax Year								2019 2020 2021 2022
Domestic Tax Authority [Member] | Internal Revenue Service (IRS) [Member]
Open Tax Year								2019 2020 2021 2022
State and Local Jurisdiction [Member]
Open Tax Year								2018 2019 2020 2021 2022
Service-based Restricted Stock [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements (in shares) | shares								242,500
Performance Shares [Member]
Incremental Common Shares Attributable to Dilutive Effect of Share-Based Payment Arrangements (in shares) | shares								25,000
Minimum [Member]
Property, Plant and Equipment, Useful Life (Year)								5 years
Maximum [Member]
Property, Plant and Equipment, Useful Life (Year)								30 years
Accounts Receivable [Member] | Customer Concentration Risk [Member]
Number of Major Customers								1	2
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer One [Member]
Concentration Risk, Percentage								55.00%	31.00%
Accounts Receivable [Member] | Customer Concentration Risk [Member] | Customer Two [Member]
Concentration Risk, Percentage									14.00%
Revenue Benchmark [Member] | Customer Concentration Risk [Member]
Number of Major Customers								1
Revenue Benchmark [Member] | Customer Concentration Risk [Member] | Customer One [Member]
Concentration Risk, Percentage								31.00%	13.00%
March 2022 Convertible Note Into Common Stock [Member]
Debt Conversion, Original Debt, Amount								$ 1,200,000	$ 0
Subsequent Event [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares	2,400,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares	$ 0.55
Subsequent Event [Member] | March 2022 Convertible Note Into Common Stock [Member]
Debt Conversion, Original Debt, Amount	$ 1,100,000
Debt Conversion, Converted Instrument, Shares Issued (in shares) | shares	2,275,000
Debt Instrument, Convertible, Shares Issuable (in shares) | shares	322,402
The February 2023 Public Offering [Member] | Subsequent Event [Member]
Stock Issued During Period, Shares, New Issues (in shares) | shares		3,900,000
Proceeds from Issuance or Sale of Equity, Total		$ 3,200,000
Cross River Warrants [Member]
Warrants and Rights Outstanding, Term (Year)			5 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares			568,720
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 2.11
Prefunded Warrant [Member] | Subsequent Event [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares		3,100,000
Common Warrant [Member] | Subsequent Event [Member]
Warrants and Rights Outstanding, Term (Year)		5 years
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares) | shares		7,000,000
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares		$ 0.55
Class of Warrant or Right, Price Per Share or Warrant (in shares) | shares		0.005
Common Stock and Common Warrants [Member] | Subsequent Event [Member]
Class of Warrant or Right, Price Per Share or Warrant (in shares) | shares		0.50
Prefunded Warrants and Common Warrants [Member] | Subsequent Event [Member]
Class of Warrant or Right, Price Per Share or Warrant (in shares) | shares		0.495
The 2022 Refinancing Agreement [Member] | East West Bank [Member] | Revolving Credit Facility [Member]
Line of Credit Facility, Fair Value of Amount Outstanding					$ 13,800,000						$ 13,800,000
Repayments of Lines of Credit					$ 8,400,000
Lines of Credit, Percentage of Net Proceeds From Receivables Financing, Payments for Refinancing.					5.00%
Lines of Credit, Value of Net Proceeds From Receivables Financing, Payments for Refinancing.					$ 1,000,000.0							$ 1,000,000.0
The 2017 Credit Agreement [Member] | East West Bank [Member] | Revolving Credit Facility [Member]
Debt Instrument, Decrease, Forgiveness						$ 4,300,000
July 2022 Convertible Note [Member]
Proceeds from Convertible Debt				$ 1,200,000
Debt Instrument, Face Amount								$ 1,200,000
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ / shares				$ 1.69				$ 1.69
July 2022 Convertible Note [Member] | Subsequent Event [Member]
Debt Instrument, Convertible, Shares Issuable (in shares) | shares	2,400,000
Cross River Revolver [Member] | Cross River [Member]
Debt Instrument, Face Amount										$ 750,000
Payment of Financing and Stock Issuance Costs, Total			$ 450,000
Cross River Exchange Note [Member] | Cross River [Member]
Payment of Financing and Stock Issuance Costs, Total			450,000
Extinguishment of Debt, Amount			750,000
The November 2022 Convertible Note [Member]
Debt Instrument, Convertible, Conversion Price (in dollars per share) | $ / shares								$ 2.11
The November 2022 Convertible Note [Member] | Minimum [Member]
Debt Instrument Convertible, Price Per Share, Minimum Equity Offering Amount Received								$ 2,000,000.0
The November 2022 Convertible Note [Member] | Cross River [Member]
Debt Instrument, Face Amount			$ 1,200,000
March 2022 Convertible Note [Member]
Debt Instrument, Face Amount								$ 1,200,000
March 2022 Convertible Note [Member] | Subsequent Event [Member]
Debt Instrument, Convertible, Shares Issuable (in shares) | shares	322,402
March 2022 Convertible Note and July 2022 Convertible Note [Member]
Incremental Common Shares Attributable to Dilutive Effect of Conversion of Debt Securities (in shares) | shares								879,947