Consolidated Statements of Operations and Comprehensive Income (Loss) - USD ($)	12 Months Ended
	May 31, 2020	May 31, 2019
Income Statement [Abstract]
Net sales	$ 4,189,924	$ 4,729,442
Cost of revenue	2,239,376	2,960,680
Gross profit	1,950,548	1,768,762
Operating expenses
General, administration and sales	4,061,621	3,180,497
Research and development	68,849	56,833
Total operating expenses	4,130,470	3,237,330
Operating (loss)	(2,179,922)	(1,468,568)
Other income (expense), net	322,980	8,919
Loss before income taxes	(1,856,942)	(1,459,649)
Income tax provision (benefit) from continuing operations	(14,638)	8,783
Net loss from continuing operations	(1,842,304)	(1,468,432)
Income from discontinued operations, including gain on sale, net of tax	5,722,879	257,442
Net income (loss)	$ 3,880,575	$ (1,210,990)
Net loss per common share from continuing operations, basic	$ (.47)	$ (0.37)
Net loss per common share from continuing operations, diluted	(0.47)	(0.37)
Net income per common share from discontinued operations, basic	1.45	0.06
Net income per common share from discontinued operations, diluted	1.45	0.06
Net income (loss) per common share, basic	0.98	(0.30)
Net income (loss) per common share, diluted	$ 0.98	$ (0.30)
Weighted average number of common shares, basic	3,939,833	4,005,795
Weighted average number of common shares, diluted	3,939,833	4,005,795
Comprehensive income (loss)
Net income (loss)	$ 3,880,575	$ (1,210,990)
Foreign currency translation adjustment	0	8,480
Total comprehensive income (loss)	$ 3,880,575	$ (1,202,510)