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Topic: Does FTDI232 chip need programming before use? (Read 13092 times) previous topic - next topic

CrossRoads

DTR output from FT232 thru 100nF cap to 328P reset, with 10K pullup & diode in parallel, keeps everything working fine.

You can see that on my simple 1284P schematic - an FTDI Basic plugs on the FTDI header to supply the DTR and serial signals.  I stopped mounting FT232 on my boards as a way to keep costs down and to make assembly easier - the FT232 TSSOP and QFRL packages  have pins that are too close for hand assembly for us.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

liuzengqiang

Thanks CR. Yes, the pins are really close. I've never soldered pins that close. Gotta learn how to drag solder. With the price of FTDI breakout boards so cheap, I've thought about just using them. Thing is, I want to make my device independent from ebay market trends :)
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

CrossRoads

We tried 10 times, could only make 5 work, got 5 boards we could not salvage for FTDI. Even tried sending the cards out. Designs made to use FTDI modules since then. Price of chip plus connector plus cap & other parts is about a wash vs a module plus the parts don't need mounting. Can supply boards less a module also to lower cost as an option.
FT232, CP2102, PL2303, 16U2/8U2, or something, lots of ways to a USB/Serial interface.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

liuzengqiang

My board area is also limited to free version of EAGLE. I'm making something open source. Gotta stay on the free version side of things so others can easily use and modify. I'll run out of board edge space for connectors if I use a breakout board.

So my experience with SMD is the SOIC (0.05" pitch) and the TQFP (0.8mm or 0.031" pitch). SOIC was no problem. TQFP was difficult for me. Did 3 only and struggled with a few pins. I'm going to learn drag soldering before trying the SSOP(0.025" or 0.635mm). I've been soldering with an iron.

How has your experience with SOIC and TQFP been?
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

CrossRoads

0.05" and TQFP, 328P-AU space, is not too bad. Use a stencil, solder paste, and reflow oven. TSSOP is too small tho.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

liuzengqiang


0.05" and TQFP, 328P-AU space, is not too bad. Use a stencil, solder paste, and reflow oven. TSSOP is too small tho.


I see. You used a lot of itead PCB service. Have you considered using their assembly service to help you with the SSOP etc.?
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

CrossRoads

Nope. I use cbas-usa in CA for assembling small stuff. Will occassionally buy small parts on DIP adapters from proto-advantage.com in CA. They'll buy the chips and install on adapters for you.  Will get back to my ADC to SD card for playback thru DAC later project eventually.

Stuff for my own use or for planned kits, I stay away from the really small stuff . 0805 for Rs, Cs, DIPs when I can, larger size SMDs for chips.

Stuff I design for others, I warn them about small sizes and then they're on their own for assembly. Especially where a double sided board with components on both sides that has more parts than should be allowed in a design are used!
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

graynomad

#22
Oct 02, 2014, 08:07 am Last Edit: Oct 02, 2014, 08:15 am by Graynomad Reason: 1
I soldered an FTDI TSSOP-28 using paste and a hot air gun, worked just fine, but my last board had a lot of fine-pitch chips (both sides) so I had the PCBA done for me.





______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

CrossRoads

I pay a lot more attention to pads & where traces come off the pads now, but I farm out assy where really small parts are used.
I have a 2560 mega on a board designed, will brave putting a chip on one of these weekends.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

CrossRoads

Need to remember to order a crystal also.
Designing & building electrical circuits for over 25 years.  Screw Shield for Mega/Due/Uno,  Bobuino with ATMega1284P, & other '328P & '1284P creations & offerings at  my website.

liuzengqiang

Rob,

That board looks great! Is there any particular rules you follow regarding orientation and spacing of your various components?
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

liuzengqiang

CR,

I am trying to make a design and go through some PCBA service with itead or seeed so that this device can be readily ordered by any physics teacher with my design files and BOM. Otherwise only those with a lot of knowledge of electronics can make and the device. I'll let you know how the PCBA process goes.
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

bobcousins

I've found that parts of 0805 size and SOIC pitch can be soldered OK with small amount of magnification, using fine tip soldering iron and solder. I tried some other techniques like solder paste and heat gun without consistent success, what really kicked my SMT into high gear was buying a cheapish stereo microscope, with wide field x10 eyepieces. With practice I can do QFP and TSSOP without problem, I am moving to 0603 part also.

That's ok for 1 offs,  I wouldn't want to make multiple boards with that method. I think solder paste and reflow oven (toaster oven) is the way to go there.

I think without an effective SMT technique and cheap PCBs from China I would be doing a lot less hardware projects. I've nothing against DIP and 0.1 stripboard, I spent many a year building those, but now most of the chips I am interested in are not available in 0.1 packages.

Btw, Microchip do a USB-serial chip in SOIC package, MCP2200, which is pretty handy.

Please ask questions in the forum so everyone can benefit. PM me for paid work.

liuzengqiang

bobcousins,

Thanks. So with the MCP2200, how easy is it to install windows driver? Do you have experience using it on mac or linux?

Why is everyone replying this thread a Bob, Rob, or Robert?! ;)
Serial LCD keypad panel,phi_prompt user interface library,SDI-12 USB Adapter

graynomad

Quote
Is there any particular rules you follow regarding orientation and spacing of your various components?

Yep, I place stuff wherever it fits :)

Obviously I pay attention to where things are in terms of trying to optimise traces, but these days I don't place anything on a grid or worry about orientation or anything that's not a specific technical thing.

And the old "vertical on one side and horizontal on the other side" has gone out the window as well, with large components totally blocking one side it's not practical any more IMO. That Mega2560 for example, you can't fit traces between the pins so almost that entire area is blocked on the top layer, no way to enforce "vertical only" rules.

______
Rob
Rob Gray aka the GRAYnomad www.robgray.com

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