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Back to the Future - making an SX48 Proto Board ? — Parallax Forums

Back to the Future - making an SX48 Proto Board ?

CounterRotatingPropsCounterRotatingProps Posts: 1,132
in General Discussion
OK, I did do my homework first :)

Despite the SX chip's EOL, and that I've not used them in a few years, I still like them and have a few new projects that they would work great on.

Considering the Parallax store has 61k+ units of the SX48 TQFP available for 77 cents a piece, they're really tempting.

A few days ago, I got the IDE (on Win7), SX-Key, and both a Tech and Proto board to fly again - actually was surprisingly easy to get going. (Except I pulled my hair out for a few minutes trying to run Debug. Yup, I forgot to pull the resonator off to allow the SX-Key to do the clocking. Oops. That's why it's good I still also have all the books.)

So, I've been hunting 'round for the old Parallax Proto Boards - or the Robotworkshop SX OEM board --- of course, no one that I could find has any - probably sold out years ago.

Not having done a board design in decades, I think I could do one with Eagle. Not sure about soldering a TQFP though - got a good iron, but no pick and place machine - and that drag soldering thang is a bit intimidating. LOL.

I know there are a few of you here that run board shops ... suggestions ?
To Parallax: could the Proto Board production files be made available open source ? That would be wonderful.

thx
- And, sorry, none of my SX-based projects are "Mr. Fusion" ...

Comments

  • jmgjmg Posts: 15,173
    CounterRotatingProps wrote: »
    Considering the Parallax store has 61k+ units of the SX48 TQFP available for 77 cents a piece, they're really tempting.
    I wonder if some intern at Parallax could be given the task of a breakout board for the SX48 ?
    Parallax should be able to mount that, and sell for under $4, and help reduce that sunk-cost stock pile ?
    (they have a SMD PSU board for $3.87, with manually mounted parts..)

    I see many Chinese kits offer SMD pre-mounted, users add everything else approach.

  • K2K2 Posts: 693
    jmg wrote: »
    I wonder if some intern at Parallax could be given the task of a breakout board for the SX48 ?
    Parallax should be able to mount that, and sell for under $4, and help reduce that sunk-cost stock pile ?
    (they have a SMD PSU board for $3.87, with manually mounted parts..)

    I see many Chinese kits offer SMD pre-mounted, users add everything else approach.

    Can't express how much I'd love to see this happen. Do it! Do it! Do it! Do it! Do it! Do it!

  • Peter JakackiPeter Jakacki Posts: 10,193
    I would consider these chips a "write-off" in terms of assets and selling them individually even at 77 cents apiece would cost. Better to sell 100 for $40 than 77 cents one hundred times. However at present those chips cost the company practically nothing anymore but once they start manufacturing a board it costs money up front. How many will they sell and over what time? With the costs amortized over a few dozen boards I can see them selling for hundreds of dollars. Perhaps some entrepreneur could make an offer for the remainder, spend some more money and build thousands of proto boards, stock them, advertise them, and then wait for all those orders to roll in.......

    Better to let sleeping dogs lie and dead donkeys buried.
  • BeanBean Posts: 8,129
    The problem is you need the SX-Key to program them.
    The SX-Key is $99.

    Who is going to spend $99 to be able to program a $0.77 chip ?

    Bean
  • jmgjmg Posts: 15,173
    Peter Jakacki wrote: »
    Better to let sleeping dogs lie and dead donkeys buried.
    Well, yes, they are a dead end, ... but I was trying to think of ways to move stock...
    Bean wrote: »
    The problem is you need the SX-Key to program them.
    The SX-Key is $99.

    Who is going to spend $99 to be able to program a $0.77 chip ?
    Good point, - given you can buy 50MHz MCUs from 62c/100, even the chip price is not that compelling, and the SX-Key is quite expensive.
    Atmel/Microchip, Silabs, etc have full Debug on boards for $10-25 regions.

  • CounterRotatingPropsCounterRotatingProps Posts: 1,132
    oops - I didn't mean to start a discussion over the pros and cons of reanimating the SX !

    This is merely for my own projects. I have the SX-Key (in fact, two of them). Sure, I could get the other MCU's jmg mentions, but I have the SX stuff already.

    Seems like a protoboard would be cheap to make.

    Still hoping Parallax might open source it ...

  • CounterRotatingPropsCounterRotatingProps Posts: 1,132
    jmg wrote: »
    Peter Jakacki wrote: »
    ... Atmel/Microchip, Silabs, etc have full Debug on boards for $10-25 regions.

    Ok, let's steer the thread in that direction for a bit, if you will. Do you mean "full debug on-board the board", or JTAG-ish?

    Many of the MCU dev boards also require programmers / debuggers - pretty much what the SX-Key is for the SX. One of the reasons I'm looking again at the SX is the only two JTAG debuggers I had were ruined in a flood. The SX-Key was above water :-/ (*) So I'd rather spend my limited funds on things I have still.

    I've had good experiences with Atmel and Microchip, but haven't looked at their gear since before MC gobbled up Atmel.

    Any recommendations for something comparable to the SX that doesn't require external plugs/programmer/debugger?

    thanks!
    - H

    (* Yah, long, bad story named, "Hurricane Matthew" - my neighbor's story is worse - one of our 80 foot tall trees fell on his roof - yikers :o and it had one of my ISM antennas on it - ouch. )
  • jmgjmg Posts: 15,173
    edited 2017-05-04 00:11
    CounterRotatingProps wrote: »
    ... Atmel/Microchip, Silabs, etc have full Debug on boards for $10-25 regions.

    Ok, let's steer the thread in that direction for a bit, if you will. Do you mean "full debug on-board the board", or JTAG-ish?
    Modern MCUs use two pin, or one pin debug interfaces.
    They have some on-silicon support for a modest number of breakpoints, and a link to the PC via a Debug Bridge MCU.
    CounterRotatingProps wrote: »
    Many of the MCU dev boards also require programmers / debuggers - pretty much what the SX-Key is for the SX. One of the reasons I'm looking again at the SX is the only two JTAG debuggers I had were ruined in a flood. The SX-Key was above water :-/ (*) So I'd rather spend my limited funds on things I have still.

    I've had good experiences with Atmel and Microchip, but haven't looked at their gear since before MC gobbled up Atmel.

    Any recommendations for something comparable to the SX that doesn't require external plugs/programmer/debugger?

    let's Start with what a SX48 had

    The on-chip functions of the SX48BD-G include two general-purpose 16-bit timers, an analog comparator, watchdog timer, a power-save mode with wakeup capability, a configurable internal oscillator and high-current outputs;
    262 bytes of RAM for speed
    4KB of EEPROM for programming
    36 I/O pins, enough for most applications
    Up to 75 MIPS for speed
    Internal oscillator (32 kHz to 4 MHz)
    Package: 48-pin TQFP


    4MHz Osc, 262 bytes of RAM and 4kB, 2 timers, no ADC, no UART, no i2c, no SPI, no PWM, is quite modest these days.

    some candidates for Small MCU / Debug Included Eval boards could be...

    Starting with cheapest/most general devices...
    https://direct.nuvoton.com/en/nutiny-n76e003
    https://direct.nuvoton.com/en/nutiny-n76e885

    any one of this series from Silabs (include a LCD display, so the price is sub $30)
    http://www.findchips.com/search/SLSTK20
    These EFM8 MCUs come up to 64kF, 4.25kR, 72MHz with high performance Analog A/D 20x14b, D/A 4x12b (EFM8LB1)

    or any of the Xplained Mini series Eval PCBs from Atmel/Microchip
    https://www.digikey.com/products/en?keywords=xplained mini

    or, for 32b, Wide Vcc, maybe any of these XMC1xxx eval boards
    https://www.digikey.com/products/en/development-boards-kits-programmers/evaluation-boards-embedded-mcu-dsp/786?k=XMC1

    addit: another 32b one, coming soon...FLiP
    https://www.parallax.com/product/32123
  • CounterRotatingPropsCounterRotatingProps Posts: 1,132
    Wonderful, jmg - excellent review and summary - thank you so much! I came across the Xplained stuff while you were posting your reply ... so I guess I'm on the right track. - H
  • jmgjmg Posts: 15,173
    CounterRotatingProps wrote: »
    Wonderful, jmg - excellent review and summary - thank you so much! I came across the Xplained stuff while you were posting your reply ... so I guess I'm on the right track. - H
    I added another one above, not released yet, but close : the FLiP from Parallax.
    Small form factor, with USB-link & SMPS included, but no Native Debug, however you can use a COG for debug messages.

  • VonSzarvasVonSzarvas Posts: 3,451
    Looks like FLiP has a ship date and is open for pre-orders. They might sell out before they ship the first batch!
  • jmgjmg Posts: 15,173
    VonSzarvas wrote: »
    Looks like FLiP has a ship date and is open for pre-orders. They might sell out before they ship the first batch!
    Nicely packaged.
  • homosapienhomosapien Posts: 147
    edited 2017-05-04 23:22
    FYI - I have about 25 of the SX-52 boards in stock. I use 2-3 per year for 1-off projects that need exactly what they have (lots IO, speed, output drive, turn-key module).

    I find they are the kind of thing that is nice to have around for emergency/oddball projects. However if anyone needs 1 or 2 I could be persuaded to sell for $20 + shipping/ each.


    Nate
  • CounterRotatingPropsCounterRotatingProps Posts: 1,132
    Hi homosapien - can you post a pic of that board, please - I don't remember what the '52 boards have. I might be interested in it. thanks -H
  • PublisonPublison Posts: 12,366
    edited 2018-05-16 19:41
    CounterRotatingProps wrote: »
    Hi homosapien - can you post a pic of that board, please - I don't remember what the '52 boards have. I might be interested in it. thanks -H



    First post has a picture:

    http://forums.parallax.com/discussion/79753/ready-to-use-sx52-proto-board




  • CounterRotatingPropsCounterRotatingProps Posts: 1,132
    Homosapien, is it the same board as Publison posts ? thx - H
  • homosapienhomosapien Posts: 147
    edited 2017-05-08 11:27
    Yes, that is a picture of the SX-52 boards that I have.

    The boards I have are unused, therefore no headers in the prototyping area. They also need a resonator of your choice to be inserted into the resonator socket (light blue component in the picture).


    Nate
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