Note 7 - Stockholders' Equity (Details Textual)		9 Months Ended	12 Months Ended
	Jul. 01, 2014 $ / shares shares	Mar. 31, 2021 USD ($)	Jun. 30, 2021 USD ($) $ / shares shares	Jun. 30, 2020 USD ($) $ / shares shares
Common Stock Voting Rights Votes Per Share			1
Shares Held by Subsidiaries (in shares)			704,309	704,309
Stock Issued During Period, Value, Issued for Services | $			$ 72,000	$ 16,350
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.75
Proceeds from the Sale of Units | $			$ 1,860,000	1,584,000
Payments of Stock Issuance Costs | $			161,000	147,900
Adjustments to Additional Paid in Capital, Warrant Issued | $			2,500	2,500
Proceeds from Issuance of Common Stock | $			$ 300,000
Class of Warrant or Right, Exercised During Period (in shares)			4,065,988
Common Stock Shares Issued upon Exercise of Warrants (in shares)			4,065,988
Warrants Exercised for Common Stock | $			$ 3,049,490
Stock Issued During Period, Shares, Commission on Sale of Units and Warrant Exercises (in shares)			129,364
Payments of Commissions on Exercise of Warrants | $			$ 3,537
Class of Warrant or Right, Outstanding (in shares)			21,900,000
Weighted Average Exercise Price for Outstanding Warrants (in dollars per share) | $ / shares			$ 0.73
Weighted Average Remaining Contractual Life for Outstanding Warrants (Year)			2 years 292 days
Share-based Payment Arrangement, Noncash Expense, Total | $			$ 1,126,481	$ 2,589,134
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			960,000	2,210,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Vested in Period, Fair Value | $			$ 1,017,700	$ 429,200
Share-based Payment Arrangement, Nonvested Award, Option, Cost Not yet Recognized, Amount | $			$ 0
Warrants with Extended Expiration Dates [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.75
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			4,497,924
Modification of Warrants | $			$ 25,506
Interest Expense Related to the Modification of Warrants | $			$ 187,139
Warrants Expired [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			164,251
Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares)			36,000,000
Share-based Payment Arrangement, Expense | $			$ 1,107,700	$ 429,200
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			960,000	2,210,000
Stock Option Held by Employees and Consultants [Member]
Share-based Payment Arrangement, Noncash Expense, Total | $				$ 626,058
Subscription Agreement [Member]
Share Price (in dollars per share) | $ / shares			$ 0.75	$ 0.75
Shares Issued, Price Per Share (in dollars per share) | $ / shares			$ 0.50	$ 0.50
Number of Warrants Per Unit (in shares)			1	1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.50	$ 0.50
Sale of Units, Number Of Units Issued (in shares)			3,720,000	18,000
Proceeds from the Sale of Units | $			$ 1,860,000	$ 9,000
Proceeds from Sale of Units, Net of Commissions | $			1,699,000	8,100
Payments of Stock Issuance Costs | $			$ 161,000	$ 900
Stock Issued During Period, Shares, New Issues (in shares)			3,720,000	18,000
Class of Warrant or Right, Issued During Period (in shares)			3,720,000	9,000
Warrant Fair Value Price Per Share (in dollars per share) | $ / shares			$ 0.05	$ 0.05
Adjustments to Additional Paid in Capital, Warrant Issued | $			$ 114,148	$ 333
Adjustments to Additional Paid in Capital, Other | $			$ 1,745,852	$ 8,667
Warrant Component of Equity Unit, Number of Shares of Restricted Common Stock Called by Each Warrant (in shares)			1
Subscription Agreement [Member] | Restricted Stock [Member]
Number of Shares Per Unit (in shares)			1	1
Subscription Agreement Two [Member]
Share Price (in dollars per share) | $ / shares				$ 0.75
Number of Warrants Per Unit (in shares)				1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares				$ 0.50
Sale of Units, Number Of Units Issued (in shares)				2,000,001
Proceeds from the Sale of Units | $				$ 1,000,000
Proceeds from Sale of Units, Net of Commissions | $				910,500
Payments of Stock Issuance Costs | $				$ 89,500
Stock Issued During Period, Shares, New Issues (in shares)				2,000,001
Class of Warrant or Right, Issued During Period (in shares)				2,000,001
Warrant Fair Value Price Per Share (in dollars per share) | $ / shares				$ 0.05
Adjustments to Additional Paid in Capital, Warrant Issued | $				$ 48,604
Adjustments to Additional Paid in Capital, Other | $				$ 951,396
Warrant Component of Equity Unit, Number of Shares of Restricted Common Stock Called by Each Warrant (in shares)				1
Subscription Agreement Two [Member] | Restricted Stock [Member]
Number of Shares Per Unit (in shares)				1
Subscription Agreement Three [Member]
Share Price (in dollars per share) | $ / shares				$ 0.75
Number of Warrants Per Unit (in shares)				1
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares				$ 0.50
Sale of Units, Number Of Units Issued (in shares)				1,150,000
Proceeds from the Sale of Units | $				$ 575,000
Proceeds from Sale of Units, Net of Commissions | $				517,500
Payments of Stock Issuance Costs | $				$ 57,500
Stock Issued During Period, Shares, New Issues (in shares)				1,150,000
Class of Warrant or Right, Issued During Period (in shares)				1,150,000
Warrant Fair Value Price Per Share (in dollars per share) | $ / shares				$ 0.05
Adjustments to Additional Paid in Capital, Warrant Issued | $				$ 25,041
Adjustments to Additional Paid in Capital, Other | $				$ 549,959
Warrant Component of Equity Unit, Number of Shares of Restricted Common Stock Called by Each Warrant (in shares)				1
Subscription Agreement Three [Member] | Restricted Stock [Member]
Number of Shares Per Unit (in shares)				1
Minimum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.60
Minimum [Member] | Warrants Expired [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			0.75
Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			1.50
Maximum [Member] | Warrants Expired [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 2
Maximum [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year)			10 years
Employees and Consultants [Member]
Stock Issued During Period, Shares, Issued for Services (in shares)				29,000
Stock Issued During Period, Value, Issued for Services | $				$ 16,350
Employees and Consultants [Member] | Minimum [Member]
Share Price (in dollars per share) | $ / shares				$ 0.48
Employees and Consultants [Member] | Maximum [Member]
Share Price (in dollars per share) | $ / shares				$ 0.75
President [Member]
Shares Issued, Price Per Share (in dollars per share) | $ / shares			$ 0.50
Number of Shares Per Unit (in shares)				1
Number of Warrants Per Unit (in shares)			1	1
Warrant Component of Equity Unit, Number of Shares of Restricted Common Stock Called by Each Warrant (in shares)			1
Deferred Compensation, Converted to Units, Amount | $			$ 128,039	$ 3,828
Loan Payable Converted to Units, Amount | $				15,000
Accounts Payable, Converted to Units, Amount | $			$ 52,361	$ 52,830
Deferred Compensation and Accounts Payable Converted to Units, Shares (in shares)			360,805	143,316
Deferred Compensation, Loan Payable, and Accounts Payable Converted to Units, Price Per Unit (in dollars per share) | $ / shares			$ 0.50	$ 0.50
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)				1
President [Member] | Warrants Related to the Conversion of Deferred Compensation and Accounts Payable into Units [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.75	$ 0.75
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
President [Member] | Warrants Issued in Connection with Sale of Units in Exchange for Salary [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.75
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
President [Member] | Restricted Stock [Member]
Number of Shares Per Unit (in shares)			1
President [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Plan Modification, Incremental Cost | $		$ 8,775
Share-based Payment Arrangement, Expense | $			$ 277,500	$ 115,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			250,000	600,000
President [Member] | Stock Option Held by Employees and Consultants [Member]
Share-based Payment Arrangement, Noncash Expense, Total | $				$ 110,625
President [Member] | Sale of Units in Exchange for Salary [Member]
Number of Warrants Per Unit (in shares)			1
Sale of Units, Number Of Units Issued (in shares)			144,000
Sale of Units in Exchange for Salary and Expense, Salary Amount | $			$ 72,000
President [Member] | Sale of Units in Exchange for Salary [Member] | Restricted Stock [Member]
Number of Shares Per Unit (in shares)			1
An Investor [Member]
Stock Issued During Period, Shares, New Issues (in shares)			300,000
Proceeds from Issuance of Common Stock | $			$ 300,000
Two Consultants [Member]
Shares Issued, Price Per Share (in dollars per share) | $ / shares			$ 0.50
Number of Warrants Per Unit (in shares)			1
Deferred Compensation, Converted to Units, Amount | $			$ 593,411
Deferred Compensation and Accounts Payable Converted to Units, Shares (in shares)			1,186,824
Deferred Compensation, Loan Payable, and Accounts Payable Converted to Units, Price Per Unit (in dollars per share) | $ / shares			$ 0.50
Two Consultants [Member] | Warrants Related to Deferred Compensation Conversions [Member]
Class of Warrant or Right, Number of Securities Called by Each Warrant or Right (in shares)			1
Two Consultants [Member] | Restricted Stock [Member]
Number of Shares Per Unit (in shares)			1
Consultant [Member]
Class of Warrant or Right, Issued During Period (in shares)			50,000
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			50,000
Class of Warrant or Right, Issued During the Period, Value Issued for Expenses | $			$ 2,500
Consultant [Member] | Maximum [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.90
Brokers [Member] | Warrants Issued as Commissions Expiring at December 31, 2022 [Member]
Class of Warrant or Right, Number of Securities Called by Warrants or Rights (in shares)			322,000
Brokers [Member] | Warrants Issued as Commissions [Member]
Class of Warrant or Right, Exercise Price of Warrants or Rights (in dollars per share) | $ / shares			$ 0.75
Chief Executive Officer [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Expense | $			$ 277,500	$ 90,000
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			250,000	500,000
Chief Executive Officer [Member] | Stock Option Held by Employees and Consultants [Member]
Share-based Payment Arrangement, Noncash Expense, Total | $				$ 184,550
Executive Vice Chairman [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Expense | $			$ 55,500	$ 33,250
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			50,000	175,000
Executive Vice Chairman [Member] | Stock Option Held by Employees and Consultants [Member]
Share-based Payment Arrangement, Noncash Expense, Total | $				$ 116,970
Secretary and Director [Member] | Share-based Payment Arrangement, Option [Member]
Share-based Payment Arrangement, Expense | $			$ 27,500	$ 28,750
Share-based Compensation Arrangement by Share-based Payment Award, Options, Grants in Period, Gross (in shares)			25,000	150,000
Secretary and Director [Member] | Stock Option Held by Employees and Consultants [Member]
Share-based Payment Arrangement, Noncash Expense, Total | $				$ 32,700
Centerpoint [Member]
Shares Held by Subsidiaries (in shares)			704,309
Series B Preferred Stock [Member]
Preferred Stock, Shares Outstanding, Ending Balance (in shares)	200		200	200
Preferred Stock, Par or Stated Value Per Share (in dollars per share) | $ / shares	$ 0.01		$ 0.01	$ 0.01
Preferred Stock, Convertible Option Per Share (in dollars per share) | $ / shares	$ 2
Preferred Stock, Dividend Rate, Percentage	2.50%
Preferred Stock, Redemption Price Per Share (in dollars per share) | $ / shares	$ 100
Convertible Preferred Stock Redemption Period (Year)	3 years
Dividends, Preferred Stock, Total | $			$ 2,000	$ 2,000
Dividends Payable | $			$ 20,000