Consolidated Statements of Operations and Comprehensive Loss - USD ($) shares in Thousands, $ in Thousands	12 Months Ended
	Sep. 30, 2020	Sep. 30, 2019	Sep. 30, 2018
Income Statement [Abstract]
Revenue	$ 110,128	$ 87,265	$ 85,617
Cost of revenue	74,546	72,176	67,130
Gross profit	35,582	15,089	18,487
Operating expense (income):
Selling, general, and administrative	24,631	32,080	21,377
Research and development	20,269	19,443	15,387
(Gain) loss on sale of assets	(2,284)	(302)	34
Total operating expense	42,616	51,221	36,798
Operating loss	(7,034)	(36,132)	(18,311)
Other income:
Interest (expense) income, net	(104)	629	733
Foreign exchange gain (loss)	198	(427)	(434)
Other income			110
Total other income	94	202	409
Loss before income taxes	(6,940)	(35,930)	(17,902)
Income tax (expense) benefit	(60)	(54)	449
Net loss	(7,000)	(35,984)	(17,453)
Foreign exchange translation adjustment	(32)	65	324
Comprehensive loss	$ (7,032)	$ (35,919)	$ (17,129)
Per share data:
Net loss per basic and diluted share (in dollars per share)	$ (0.24)	$ (1.29)	$ (0.64)
Weighted-average number of basic and diluted shares outstanding	29,136	27,983	27,266