Building IOCards

I have ordered the kits on the IOCards website. They also sell fully built and tested boards instead of kits. However, i went with the kits as my goal is also to learn as much as possible. Having the kits gave me the opportunity to learn more about various electronic components and ample practice with soldering. If you let them build, the extra few bucks you need to pay are still worth paying to them, considering the time they have to spen soldering a large no of contacts (specially on master card).

Package from IOCards folks in Spain arrived in about 8 days (btw, i am in US). The PCBs are of excellent industrial quality, each component location well identified with clean legends making it really easy to solder the components. I had to rarely refer to the scheme diagram. Refer to the IOCards website for further information such as components lists and scheme diagrams etc.,

First of all thanks to IOCards folks for their excellent work and providing a great service by supplying these kits at a very reasonable price.

Few things before you start building the cards:

1) Needless to say - get yourself a good multimeter. I bought mine from a local Radioshack store ( http://www.radioshack.com/product.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F008%5F002%5F000&product%5Fid=22%2D813 ).

2) IOCards kits does not include IC sockets. Get yourself a couple of these sockets as listed to plugin the ICs inlcuded in the kit:

For USB expansion card: 16 pin (2 nos), 20 pin (8 nos).
For Master card: 16 pin (8 nos), 24 pin (1 no)
For Displays card: 16 pin (4 nos), 20 pin (1 no), 24 pin (1 no)

One of the sockets (24 pin) i have ordered online turned out to be wider than the distance between the two rows (width of the ic)on the pcb. I solved the problem by breaking the socket in the middle into two seperate columns and soldered each seperately.

3) PCB mounting screws - one each on the four corners of USB and master card

I haven't had all these ready at the time i sat down to build these cards and local radioshack stores did not have all of them available. I had to go to 3 different radioshack stores and still did not find all of them. Finally ended up waiting for one more week and ordered them online at Mouser ( http://www.mouser.com ).


Things you need after you built these 3 cards:

1) a 25 pin Male to Female cable (DB25 M to F) to connect master card with the USB card

2) a 40 conductor cable (a flat ribbon cable is preferable) to connect 40 male IDC socket on the master card to the similar one on the displays card.

3) A steady 5V dc power supply (preferably from a PC powersupply).

As mentioned, soldering the components is quite straight forward. All component locations on the pcb are clearly marked.

Only issue that one will run into is with the USB Kit. USB kit as shipped has missing part: 220 nF Ceramic Capacitor (C1). Instead kit includes an extra 0.1 mF capacitor. This is ok and is due to a later design change. Go ahead and use 0.1 mF capacitor inplace of the listed 220 nF for C1.

POWER SUPPLY FOR MASTER CARD
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Though USB expansion card is the one connected to the computer, it doesnot need external powersupply. However each master card connected to it requires a steady 5V DC power input. The best steady source is a PC power supply unit. I solvaged one from an old PC given to me kindly by my friend Prasad (Thanks Prasad). You can find a tutorial on how to do this on IOCards website or here: http://web2.murraystate.edu/andy.batts/ps/PowerSupply.htm

tips for building the cards:
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1) Have a tool to cut the long component leads on the back of the pcb. You will have to cut a lots of them specially on master card. Having a proper tool is critical.
2) Do not use a high wattage solder. Mine is 15 watt type.
3) Do not weld ICs directly to the board. Use sockets.


The lessons i learned from this very first milestone activity is - this is going to be a long term activity and i need to learn to be patient. If a part or two is missing, i need to take it easy and learn to wait until the next weekend to get it from online stores. Impulsively buying from a local store may not be possible and/or it is going to cost you a lot more. So plan much in advance or take it easy and wait. For example, price of a 6ft 25db cable in local compUSA is around $20.00 and a 10ft cable of same type online is $5.00 approximately.

Oh btw, i cannot forget to thank my wife vijju for helping me with building these cards. She sat with me, learned how to solder and built the displays card all by herself. Thanks chinna.

Next week, i will be hooking up the boards with the IOCards software and start testing them....