Note 4 - Revenue - Disaggregation By Revenue (Details) - USD ($)	3 Months Ended		6 Months Ended
	Mar. 28, 2020	Mar. 30, 2019	Mar. 28, 2020	Mar. 30, 2019
Net revenue	$ 722,751	$ 1,928,468	$ 1,388,676	$ 3,040,813
Engineering Services [Member]
Net revenue	457,818	877,080	866,642	1,867,519
Equipment Sales [Member]
Net revenue	$ 264,933	$ 1,051,388	$ 522,034	$ 1,173,294