Condensed Consolidated Balance Sheets - USD ($)	Mar. 31, 2021	Dec. 31, 2020
Current assets:
Cash	$ 548,000	$ 1,836,000
Trade accounts receivable, less allowances of $14 and $8, respectively	1,492,000	2,021,000
Inventories, net	7,515,000	5,641,000
Short-term deposits	784,000	796,000
Prepaid and other current assets	778,000	782,000
Total current assets	11,117,000	11,076,000
Property and equipment, net	482,000	420,000
Operating lease right-of-use assets	676,000	794,000
Restructured lease right-of-use assets	54,000	107,000
Total assets	12,329,000	12,397,000
Current liabilities:
Accounts payable	3,437,000	2,477,000
Accrued liabilities	177,000	45,000
Accrued legal and professional fees	19,000	149,000
Accrued payroll and related benefits	787,000	885,000
Accrued sales commissions	29,000	95,000
Accrued restructuring	5,000	11,000
Accrued warranty reserve	239,000	227,000
Deferred revenue	73,000	72,000
Operating lease liabilities	609,000	598,000
Restructured lease liabilities	85,000	168,000
Finance lease liabilities	3,000	3,000
PPP loan	0	529,000
Credit line borrowings, net of loan origination fees	3,416,000	2,298,000
Total current liabilities	8,879,000	7,557,000
Operating lease liabilities, net of current portion	172,000	318,000
Finance lease liabilities, net of current portion	0	1,000
PPP loan, net of current maturities	0	266,000
Total liabilities	9,051,000	8,142,000
STOCKHOLDERS' EQUITY
Preferred stock, par value $0.0001 per share	0	0
Common stock, par value $0.0001 per share	0	0
Additional paid-in capital	135,778,000	135,113,000
Accumulated other comprehensive loss	(3,000)	(3,000)
Accumulated deficit	(132,497,000)	(130,855,000)
Total stockholders' equity	3,278,000	4,255,000
Total liabilities and stockholders' equity	$ 12,329,000	$ 12,397,000