How to fabricate the IRX2.0 Printed Circuit board

Step 1: Choose a PC Fabrication House

There are many companies that will fabricate PC boards directly from machine-readable design files. Currently, my favorite company of choice is Lone Star Circuits--they do excellent work at significantly lower prices than other companies I've found.

Company	Phone	FAX	Contact
Lone Star Circuits	(972) 771-1930	(972) 771-0360	Theda Medley
Quick Turn Circuits, Inc.	(408) 727-4125	(408) 727-1411	Jim Khosh
West Coast Circuits, Inc.	(800) 637-3452	(408) 728-1827	Jennifer Rojas
Davila International Circuits	(415) 969-5700	(415) 969-6385	Bill Cooke

Step 2: The design files

Once you choose a PC fabrication house, you'll need to send them the design files from which they'll make the circuit boards. Most of them have a modem dial-up line and a BBS to which you can upload the files, some of them have an FTP or WEB based connection. PC fab houses universally accept DOS format files with "eight dot three" file names.

The design files are available online here. You'll need to send these files to your PC fabrication house, using whatever form of communication the fab house wants. You will typically send them the single "ZIP" file that bundles these files together.

File name	Description
irx20.gtl	Gerber format: Top ("component") side traces
irx20.gbl	Gerber format, Bottom ("solder") side traces
irx20.gts	Gerber format, Top side solder mask
irx20.gbs	Gerber format, Bottom side solder mask
irx20.gto	Gerber format: Top side silk screen
irx20.gko	Gerber format, Board outline
irx20.apt	Aperture list for the Gerber files
irx20.txt	NC drill file
irx20.drr	"Drill report" (indicates drill sizes) for NC drill file
readme.txt	Your name, contact information, list of file names, etc..

You'll send the fab house the ZIP file and a PURCHASE ORDER. Some weeks later, they'll send you completed (but unstuffed) boards. If you are using an outside service to assemble the boards, you can ask the fab house deliver the boards directly to the assembly shop.

Layout of the iRX 2.0

Step 3: Buy the components

All of the components, with the exception of the Sharp 1SU60 and the printed circuit board itself, are available from Digi-Key, a mail-order electronics part supplier. While Digi-Key is not always the cheapest, they have a large selection, take telephone credit card orders, and will get you your parts the next day via FedEx. If you have more time than money on your hands, you can probably shop around and get a better price on some of the parts shown here.

Following is a list of all the components for the LOCUST. When possible, we've shown Digi-Key's part numbers and prices (as of Jan 1997).

Bill of Materials
Ref	Digi-Key Part#	Description	unit $ [note 1]
--	-na-	Printed Circuit Board	2.60
JI	CP-002A	+9V DC Jack	0.38
--	ED3318	18 pin DIP socket	0.5254
U1	NJM78L05A	78L05 +5V voltage regulator	0.26
U2	PIC16C84-04/P	PIC16C84 processor	4.52
L1	LT1061	Infrared LED [note 2]	0.216
L2	LT1078	Red LED [note 3]	0.11
D1	1N4001CT	1N4001 diode	0.048
Y1	PX400-ND	4MHz ceramic resonator with built-in capacitors	0.5758
C1	P6224	22uF electrolytic capacitor [16V or greater]	0.0588
C2	P6224	22uF electrolytic capacitor [16V or greater]	0.0588
C3	P4914	.01uF ceramic capacitor	0.1017
R1	100QBK	100 ohm 1/8W resistor	0.01945
R2	100QBK	100 ohm 1/8W resistor	0.01945
R3	10KQBK	10K ohm 1/8W resistor	0.01945
U3	MAX233CPP	MAX233 RS-232 level converter	3.737
U4	-na-	Sharp IS1U60 Infrared Demodulator	2.50
-	-	TOTAL:	$15.22

Notes:
[Note 1] Prices shown are approximate, taken when possible from Digi-Key May 1996 catalog and assuming 100 unit pricing. Prices preceded with `*' aren't counted in the total.

[Note 2] The LT1061 infrared LED listed has a 40? viewing angle. Almost any other infrared LED may be substituted, depending on the application. Narrower viewing angles will give you a longer on-axis projection distance, but will require more accurate aiming.

[Note 3] Almost any visible LED will suffice for L2--the LT1078 shown is inexpensive and bright.

Table 5. Suppliers
Vendor	Telephone	Which parts
Digi-Key	(800) 344-4539	Everything else...
Reptron	(800) 800-5441	SHARP IS1U60
Marshall	(800) 522-0084	SHARP IS1U60
Wiley	(617) 271-9953	SHARP IS1U60
Milgray	(800) 648-3595	SHARP IS1U60
Sterling	(617) 938-6200	SHARP IS1U60

Step 4: Stuff the Boards

You may either solder the components to the circuit board yourself or send them to an outside service for assembly--it all comes down to a trade-off between time, money and patience.

Sending the boards out for assembly

I've only used one company to stuff boards: Outsource Solutions, Inc. in McKinney, TX. They've done good work: on a run of 200 ID badges, I found no defects attributable to assembly. OSI is conveniently located down the street from Lone Star Circuits (PC board fabricators).

PC Assembly Houses

I've used Outsource Solutions for assembling components on PC boards. They are conveniently located near Lone Star Circuits (see above), and I've had good luck with them. Assured Manufacturing is also a good company, they come highly recommended by Lone Star, they too are only a stones throw away from LS, and their quotes were less expensive than Outsource Solutions.

Table 7. PC Assembly Houses
Company	Phone	FAX	Contact
Outsource Solutions, Inc.	(972) 562-6253	(972) 562-7057	Jeff Benson
Assured Manufacturing	(972) 669-7900	(972) 669-7979	Dave Daniels x101
PACTRON	(408) 747-1237	(408)747-1239	Dan Graft

Step 5: The Solar Panels and Power Connectors

All Electronics sells the 9v 6" x 6" 60mA solar panels. #SPL-960 $5.25/ea 1-800-826-5432.
Digi Key has the 2.1mm DC Plug. Part# CP-004A $0.43/ea. Buy extra because these are easy to break. 1-800-344-4539

Return to the iRX2.0 home page or the LOCUST home page