Note 12 - Equity Transactions and Stock-based Compensation (Details Textual) - USD ($) | 1 Months Ended | 12 Months Ended |
Aug. 31, 2024 | Jun. 30, 2024 | Jun. 30, 2023 |
Share-Based Compensation Arrangement by Share-Based Payment Award, Number of Shares Available for Grant (in shares) | | 6,351,818 | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) | | 782,500 | 527,000 |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | | $ 0.27 | $ 0.42 |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | 3 years | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Exercisable, Intrinsic Value | | $ 129,000 | $ 461,000 |
Director [Member] | Subsequent Event [Member] | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) | 200,000 | | |
Each Director [Member] | Subsequent Event [Member] | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) | 50,000 | | |
Maximum [Member] | Director [Member] | Subsequent Event [Member] | | | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | $ 0.2 | | |
Minimum [Member] | Director [Member] | Subsequent Event [Member] | | | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | $ 0.18 | | |
Share-Based Payment Arrangement, Option [Member] | | | |
Share-Based Payment Arrangement, Expense | | 252,000 | $ 320,000 |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Amount | | $ 205 | |
Share-Based Payment Arrangement, Nonvested Award, Cost Not yet Recognized, Period for Recognition (Year) | | 2 years 6 months | |
Antidilutive Securities Excluded from Computation of Earnings Per Share, Amount (in shares) | | 2,101,683 | 4,376,284 |
Share-Based Payment Arrangement, Option [Member] | Director [Member] | Subsequent Event [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | 1 year | | |
Share-Based Payment Arrangement, Option [Member] | Director [Member] | Subsequent Event [Member] | Share-Based Payment Arrangement, Tranche One [Member] | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 25% | | |
Share-Based Payment Arrangement, Option [Member] | Director [Member] | Subsequent Event [Member] | Share-Based Payment Arrangement, Tranche Four [Member] | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 25% | | |
Share-Based Payment Arrangement, Option [Member] | Director [Member] | Subsequent Event [Member] | Share-Based Payment Arrangement, Tranche Three [Member] | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 25% | | |
Share-Based Payment Arrangement, Option [Member] | Director [Member] | Subsequent Event [Member] | Share-Based Payment Arrangement, Tranche Two [Member] | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Award Vesting Rights, Percentage | 25% | | |
Share-Based Payment Arrangement, Option [Member] | Maximum [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) | | 10 years | |
Share-Based Payment Arrangement, Option [Member] | Minimum [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) | | 5 years | |
Stock Option 2001 Plan [Member] | | | |
Share Based Compensation Arrangement by Share Based Payment Award Number of Shares Originally Authorized (in shares) | | 7,000,000 | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Additional Shares Authorized (in shares) | | 6,000,000 | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | | 13,000,000 | |
Stock Option 1997 Plan [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | | 5,000,000 | |
Stock Option 2024 Plan [Member] | Officers and Employees [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | | 592,500 | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) | | 582,500 | |
Stock Option 2024 Plan [Member] | Non-executive Directors [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Number of Shares Authorized (in shares) | | 200,000 | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) | | 200,000 | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | | $ 0.33 | |
Stock Option 2024 Plan [Member] | Maximum [Member] | Officers and Employees [Member] | | | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | | 0.26 | |
Stock Option 2024 Plan [Member] | Minimum [Member] | Officers and Employees [Member] | | | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | | $ 0.24 | |
Stock Option 2024 Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Officers and Employees [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | 3 years | |
Stock Option 2024 Plan [Member] | Share-Based Payment Arrangement, Option [Member] | Non-executive Directors [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) | | 10 years | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | 1 year | |
Stock Option Plan 2023 [Member] | Director [Member] | | | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | | | $ 0.33 |
Stock Option Plan 2023 [Member] | Officers, Employees, and Directors [Member] | | | |
Share-Based Compensation Arrangement by Share-Based Payment Award, Options, Grants in Period, Gross (in shares) | | | 738,500 |
Stock Option Plan 2023 [Member] | Officer [Member] | | | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | | | $ 0.41 |
Stock Option Plan 2023 [Member] | Employees [Member] | | | |
Share-Based Compensation Arrangements by Share-Based Payment Award, Options, Grants in Period, Weighted Average Exercise Price (in dollars per share) | | | $ 0.45 |
Stock Option Plan 2023 [Member] | Share-Based Payment Arrangement, Option [Member] | Maximum [Member] | Officers, Employees, and Directors [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) | | 10 years | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | | 3 years |
Stock Option Plan 2023 [Member] | Share-Based Payment Arrangement, Option [Member] | Minimum [Member] | Officers, Employees, and Directors [Member] | | | |
Share-based Compensation Arrangement by Share-based Payment Award, Expiration Period (Year) | | 5 years | |
Share-based Compensation Arrangement by Share-based Payment Award, Award Vesting Period (Year) | | | 1 year |