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DIP version of FTDI chip — Parallax Forums

DIP version of FTDI chip

dnaddordnaddor Posts: 26
edited 2008-03-19 13:42 in Propeller 1
Hi everyone.

I'm making prototypes of my first product using a Propeller chip. I went looking for a DIP version of the FTDI chip, but they only make modules (and they aren't cheap). I don't have the tools or the skills to do SMT.

I will preprogram the first 32K of the 128K SRAM, but the customer's PC must still communicate with the unit in order to custom program the other 96K.

I have a couple of options, but I don't like any of them.

I could buy a Parallax PropPlug ($24.95) with every unit. I was hoping to sell finished units for about $80.00, so that extra $25 is a big hit.

I could use a standard 232 chip and use a DB-9. The problem is that computers don't have serial ports anymore! I might have to include a USB-to-serial cable.

Is there some chip that's used in a USB mouse that I could use somehow?

Does anyone have any other suggestions?

Thanks!

P.S. Thank you Chip Gracey. The Propeller is really great on so many levels. I've been using PIC16C5x/SX28/SX48 for more than 10 years, but plan to switch to the Propeller exclusively.

Comments

  • Graham StablerGraham Stabler Posts: 2,510
    edited 2008-03-19 02:02
    I know this is just what you don't want to hear but I really would not be scared off by SMT, particularly the leaded types. The skills are easy to acquire and the only tools you really have to get is a flux pen and a hot thing (known as a soldering iron) plus some solder paste. If vision is an issue then get a cheap stereo microscope.

    It will also free you up with a lot of other component choices.

    Graham
  • DynamoBenDynamoBen Posts: 366
    edited 2008-03-19 02:32
    If you are looking for USB to TTL I have used these before (they are identical to the prop plug):

    http://www.dlpdesign.com/usb/usb232.shtml· (Mouser sells these)

    This will also work and is a little less expensive:

    http://www.sparkfun.com/commerce/product_info.php?products_id=718

    Hope that helps. In the end it is a lot less expensive to do some SMT soldering but at least these options will get you going.



    Post Edited (DynamoBen) : 3/19/2008 2:37:13 AM GMT
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2008-03-19 04:44
    I agree with Graham: SMT soldering skills are not that difficult to pick up. In addition to the tools he recommends, I would add non-magnetic tweezers, fine-braid solder wick, and a strategically-placed hand- or armrest. The last item makes parts alignment that much easier — especially after a couple cups of coffee. smile.gif A board vise that raises the PCB closer to eye level is also a big help.

    The FT232BM is a bit simpler to solder than the FT232R, BTW, since the lead spacing is wider. The downside to the 'BM, though, is that more external parts are required. But in any event, I wouldn't be daunted by the soldering aspect.

    -Phil

    P.S. One thing I wish I had, but have been able to do without so far, is a pair of glasses-mounted telescopes like surgeons wear — the kind that have a long working distance. The only ones I've seen are dreadfully expensive, though. The set my dental hygienist wears, for example, cost nearly $1000. If anyone knows of a less expensive source for them, I'd be grateful to know about it.
  • JavalinJavalin Posts: 892
    edited 2008-03-19 10:20
    FTDI (on the website) make prototyping dev boards with the usual 0.1" header pins!
  • hippyhippy Posts: 1,981
    edited 2008-03-19 13:42
    dnaddor said...
    I will preprogram the first 32K of the 128K SRAM, but the customer's PC must still communicate with the unit in order to custom program the other 96K.

    Presumably then this isn't using the serial in the same way as a program download needs to be done, it's under your program control and you could do it anyway you want.

    Traditional serial could be implemented using just a two-wire (TX/RX/0V) interface and a couple of resistors though not compliant to RS232. If serial isn't acceptable it will most likely have to be USB.

    The Propeller can be programmed to act as a Slave USB for serial comms with a Virtual Serial Port exposed on the PC. This would just require a USB socket on your Propeller and a few resistors plus the USB cable and driver software. That would seem to be the lowest cost method.

    I'm afraid my search didn't turn up the links to propeller USB serial, but it is on the forum somewhere.

    Added : one of the threads, including my Win98SE driver ...

    http://forums.parallax.com/showthread.php?p=675656

    Post Edited (hippy) : 3/19/2008 1:49:30 PM GMT
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