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FT232 alternative? — Parallax Forums

FT232 alternative?

kittmasterkittmaster Posts: 77
edited 2007-12-10 22:33 in Propeller 1
Has anyone tried to use an alternative uart? the ssoc footprint will be difficult to prototype out on the CNC routers due to the pitch size. Just wondering if there is something that would do the same job in a dip or soic 100mil pitch.

Thanks
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Comments

  • RaymanRayman Posts: 14,793
    edited 2007-12-07 02:07
    You want to go from USB to RS232? I'd imagine FTDI is the way to go...
  • Mike GreenMike Green Posts: 23,101
    edited 2007-12-07 02:24
    If you really mean UART, the MAX3100 is available in DIP packaging. If you are just referring to a USB to serial logic adapter, I'd get a DIP format module from FTDI. Have a look at their website for their development modules.
  • kittmasterkittmaster Posts: 77
    edited 2007-12-07 02:25
    the datasheet shows, that this is used for programming the device. If I were having production boards done, this question wouldn't even come up. But since I want to prototype it, I don't think I can get my routing bits between the smd pads.

    hmm..
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2007-12-07 02:36
    Use a Prop Clip or Prop Plug. You could even unsolder the connector from the Prop Plug and solder the whole thing to your board using a four-pin header.

    -Phil
  • kittmasterkittmaster Posts: 77
    edited 2007-12-07 02:39
    I was thinking that, but I'm really shooting for the being able to not depending upon ordering or keeping modules on hand. I really want to built it discretely.

    I'll keep it in mind though if I run out of options. At least I can build the serial aspect of it for now, but I really want to get the usb implimented at some point.
  • DroneDrone Posts: 433
    edited 2007-12-07 09:10
    I agree with Mike, I think what you want is a 0.1" dip breakout board.

    The FTDI UM232R 24 pin DIP breakout board is on this page www.ftdichip.com/Products/EvaluationKits/UM232R.htm.

    Or, design a little breakout board yourself and have a panel of them made. You might even be able to sell some.

    At www.sparkfun.com they have breakout boards with the FTDI chip, USB connector, and misc. other parts needed for both the FT-232RL (SKU#: BOB-00718, $14.95 USD) and FT245RL (SKU#: BOB-07841, $17.95 USD). But at first glance these don't look like the breakout is on 0.1" centers. But with a little ingenuity, some pins and break-apart sockets, I'm sure you could get these little sparkfun board to mount like daughter-boards.

    Good Luck,

    David
  • Gerry KeelyGerry Keely Posts: 75
    edited 2007-12-07 11:33
    Another possibility is· http://www.dontronics-shop.com/4d-Micro-USB-CE5-p-16685.html

    Regards

    Gerry
  • Paul Sr.Paul Sr. Posts: 435
    edited 2007-12-07 14:15
    I use the SparkFun BOB-00718 almost daily on various systems with my portable uOLED-96-Prop - works flawlessly.

    There is a picture (4th page of the thread about 3/4 way down) of the setup I use here: http://forums.parallax.com/showthread.php?p=679308
  • DroneDrone Posts: 433
    edited 2007-12-07 15:21
    Thanks Gerry for the Dontronics ref.

    Overall, I'm disturbed about the cost of these USB/Serial parts from the likes of FTDI. A PropPlug is $30. Even the Sparkfun breakout board is $15 and SparkFun is not known as a gouger. I would've thought someone would come up with a Prop app that deals with the USB port directly using some sort of Open USB virtual COM port driver or something. Heck, PIC parts that cost a few bucks in small quantity should at least be able to handle USB at low rates. Obviously I'm missing something here. Royaties to the USB-Cartel? Heck I was out in a shopping mall today and saw a 128MB MP3 player with a USB interface (no display) for $25 USD, and I'm sure there are cheaper examples out there. Why should we be paying so much for a seemingly simple thing? Economies of scale, licensing/Lawyers/Patents, what? Again, a PropPlug is $30, a Prop Proto-Board is $20, even in volume and PCB area compared between the two, there is something amiss here.

    End of Rant...

    David
  • kittmasterkittmaster Posts: 77
    edited 2007-12-07 16:09
    good point drone.......serious......I guess it because they are buying thousands and we are only looking for onez, twoz's......lol

    Thanks for the tips everyone, I was looking for more of any else besides FTDI that is more prototype friendly. Daughter boards work and all, but for me I'd rather have a more complete final solution. I guess I can look at a breakout board, but its more wiring and more ways for something to fail via breakout wiring.

    I'll have to plug a way a bit more.

    If I come up with something I'll post back to see what your input is.
  • hippyhippy Posts: 1,981
    edited 2007-12-07 16:22
    Drone said...
    Overall, I'm disturbed about the cost of these USB/Serial parts from the likes of FTDI. A PropPlug is $30. Even the Sparkfun breakout board is $15 and SparkFun is not known as a gouger.

    FT232RL and FT232RQ chips are just $5 as one offs, $4 at 100 off so any excessive cost cannot be laid entirely at FTDI's door. I'm at a loss to understand why a PropPlug is so much more expensive than a ProtoBoard.

    With UK supplier's 60% mark-up on ProtoBoards ($32) and only 30% mark-up on the PropPlug ($40) the differential isn't as noticeable cry.gif

    Post Edited (hippy) : 12/7/2007 4:28:45 PM GMT
  • OwenSOwenS Posts: 173
    edited 2007-12-07 17:13
    If the FT232RL isn't suitable, how about the FT232BL in a 32-Pin LQFP package? It requires more external components, but FTDI have no plans as so far to discontinue the BL parts
  • kittmasterkittmaster Posts: 77
    edited 2007-12-07 19:28
    the ft232BM seems to be the only way to go. Can't find anything else unless I move into a PIC.

    It will be a bit more difficult to solder, but at least I can route it on the machines and try to get it going.
  • Fred HawkinsFred Hawkins Posts: 997
    edited 2007-12-07 19:51
    here's a monster chip: http://focus.ti.com/docs/prod/folders/print/tusb5052.html

    $8.72 or so but I bet it chews gum too. (5 usb, 2 serial, i2c....)
  • kittmasterkittmaster Posts: 77
    edited 2007-12-07 19:56
    LOL......that would be nice, but definetely not prototype friendly......LOL

    100 pins to solder by hand....neh......
  • Fred HawkinsFred Hawkins Posts: 997
    edited 2007-12-07 21:56
    Your fortune awaits: conductive super glue.
  • DroneDrone Posts: 433
    edited 2007-12-08 06:34
    Get a 0.1" wire wrap socket, flip the chip upside down and hot glue it to the center of the socket. Solder wires to the chip then plug the wires to the pin sockets. You might even go as far as potting the thing in non-conductive epoxy resin.
  • DroneDrone Posts: 433
    edited 2007-12-08 06:51
    Hippy, I didn't look up the price of the FT232RL, $5 in ones you say - sheeesh. Today I was in a computer store and saw a USB/Serial cable in a blister pack with drivers on CDROM for $12 USD, 10% tax included. Maybe I should buy one of those and make an adapter between the RS-232 connector and a four-pin 0.1" socket instead of paying $29.95 USD for the prop-plug.

    On second thought the RS-232 on the cable is probably +/- voltage. So this means in the $12 USB/RS232 cable there's even more complexity involved compared with the $29.95 prop-plug; a USB/serial bridge function back to back with a serial/RS-232 level shifter. Imaging an FT232 back to back connected to a MAX232.

    Post Edited (Drone) : 12/8/2007 7:00:01 AM GMT
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2007-12-08 07:19
    The FT232RL comes in an SSOP-28 package (0.65mm lead pitch). SparkFun sells a breakout board for these for $3.95 that will convert the chip to a DIP. It's not as difficult as you might imagine, despite the tight lead spacing, to solder an SSOP to its pads. Once the part is lined up and a couple leads are tacked down, the rest is a breeze. Just make sure you have some good-quality solder wick on hand for cleanup, along with an ohmmeter to check for shorts.

    -Phil
  • DroneDrone Posts: 433
    edited 2007-12-08 14:48
    Phil,

    I missed these SparkFun SSOP-28 break-out boards (BOBs) when I was searching. Nice find.

    However, my problem with BOBs in-general is plugging them into DIP sockets and/or plug-protoboards. As SparkFun states on the link you provided (full URL echoed for those that save posts using "print version" www.sparkfun.com/commerce/product_info.php?products_id=500), the breakaway pin headers shown as "related items" are often too big to fit into DIP sockets and for similar reason often "stress" plug-protoboard holes to the point where they don't like taking smaller guage wires any more. I wish we could find a reasonably priced bag of qty 50s, 100s or so individual socket-pluggable pins that can be soldered into these DIP BOBs to solve this problem. Still searching. P.S. the breakaway headers with their square pins do work well for wire-wrap on a 0.1" centered perf-board, and they can be easily obtained in longer pin lengths and small quantity for multiple wraps. But I think that's not what the original poster Kitmaster is looking for. Addressing the smaller pin issue may provide Kitmaster with a solution.

    David
  • RoadsterRoadster Posts: 209
    edited 2007-12-08 17:36
    Check this post, it has a USB·to serial project using a AVR micro controller

    http://forums.parallax.com/showthread.php?p=667708
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2007-12-08 17:53
    David,

    The ideal terminals for the breakout board would be the Samtec TS series (DigiKey) in the 0.018" (.46mm) diameter. Anything above 0.020" will overstress the socket. Oddly enough, SparkFun sells machined-pin terminal strips, but the diameter, at 0.025" on one end (0.030" on the other), is too large.

    One thing I dislike about generic breakout boards, though, is that there are no pads for bypass caps which, by all rights, should be mounted close to the chip. By the time a chip lead gets routed around the board and down the connecting pin, there's so much inductance involved that any bypassing measures taken on the host PCB are compromised.

    -Phil
  • Harrison.Harrison. Posts: 484
    edited 2007-12-08 21:55
    There is already an implementation of a software usb->serial interface for the Propeller. It seems to have a few bugs that have not been fully addressed yet, probably due to lack of interest by the community...

    Anyways, here is the link: http://forums.parallax.com/showthread.php?p=675656
  • DroneDrone Posts: 433
    edited 2007-12-10 02:11
    Hi Phil, Thanks for the digikey link, unfortunately no datasheet though. These folks seem to be a go-to source for all things regarding pins: www.mill-max.com. I emailed SparkFun about the pin issue, they replied, "...we will look into stocking some smaller gauge and longer pinned headers. I understand the issues with the headers we stock." So far so good.

    Harisson, Thanks for the USB driver link. I missed that one.

    David
  • Phil Pilgrim (PhiPi)Phil Pilgrim (PhiPi) Posts: 23,514
    edited 2007-12-10 02:38
    Here's the Samtec link to the TS-series pin strips: www.samtec.com/technical_specifications/overview.aspx?series=TS. I don't know that Mill-Max makes pins molded together in strips. At least neither DigiKey nor Mouser seems to carry any.

    -Phil
  • DroneDrone Posts: 433
    edited 2007-12-10 06:24
    Thanks Phil... So to summarize in one place for Kittman (original Poster) what is needed to break out an FTDI chip to a standard 0.1" DIP footprint:

    1. Qty.-1, SparkFun SSOP to DIP Adapter 28-Pin, SKU#: BOB-00500, Unit Price: $3.95 ea.

    www.sparkfun.com/commerce/product_info.php?products_id=500

    2. Qty.-1, Breakaway Pin Header 0.1" 32 position, tin plated, Samtec P/N SAM1112-32-ND, Digikey P/N TS-132-T-A, Unit Price: $3.22 ea.

    www.samtec.com/technical_specifications/overview.aspx?series=TS

    http://search.digikey.com/scripts/DkSearch/dksus.dll?Detail?name=SAM1112-32-ND

    This solution has no parts on the breakout board other than the FTDI chip - this is a good.

    David
  • Nick MuellerNick Mueller Posts: 815
    edited 2007-12-10 07:44
    If RS 232 is universal enough (for the "U" in UART), why not a MAX3232?

    Nick

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Never use force, just go for a bigger hammer!

    The DIY Digital-Readout for mills, lathes etc.:
    YADRO
  • DroneDrone Posts: 433
    edited 2007-12-10 16:14
    Hi Nick,

    I think kittmaster (originating Poster) is looking for a USB to serial (serial at logic levels, not true RS-232 phy) solution in a DIP footprint. Nobody so-far it seems can find the likes of FTDI USB/serial in native DIP form-factor.

    The MAX3232 (DIP package P/N MAX3232CPE) takes serial logic levels to/from true RS-232. This is different from what kittmaster was asking about. Even though this thread diverges at times (mea culpa) from Kittmaster's original request (as I interpret it), in the end I think we've provided a summary solution scraped from the contributions of others herein that is best as of today. If Kittmaster isn't interested in the solutions (Hello - Kittmaster?), at least the thread is here for others.

    Happy Holidays...

    David
  • kittmasterkittmaster Posts: 77
    edited 2007-12-10 16:22
    LOL

    Still here, yes drone you are spot on. While I understand the new parts have less components, they are very difficult to prototype and solder by hand. I have 1/64th tips to do the job, but its getting the copper cut properly.

    I am still looking for a native solution, the ssop is just way to small to be done by hand so is the QFN. The BM device is the only footprint that is remotely possible to properly prototype hence way I got a few samples of it.

    I understand there are breakout boads, but I don't want that, my final design shall not have any type of daughter board since it will add to possible failure into the design.

    THis is for automotive application and the vibration over time.....is well.....something I want to avoid.

    At this point I'm also consideringa PIC solution since I can't find a proper dip version.......but I understand why dips are not used (usb keys and such)
  • Nick MuellerNick Mueller Posts: 815
    edited 2007-12-10 16:56
    > The MAX3232 (DIP package P/N MAX3232CPE) takes serial logic levels to/from true RS-232.
    > This is different from what kittmaster was asking about.

    He's been asking for a UART. A "universal asynchronus receiver / transmitter".
    Quite a vague question, leaving room for interpretation what he really meant.
    A different UART for the propeller would be just a different COG. smile.gif


    Nick

    ▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔▔
    Never use force, just go for a bigger hammer!

    The DIY Digital-Readout for mills, lathes etc.:
    YADRO
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