$35 Mini Propeller Module: PropBSC --- cancelled

WBA ConsultingWBA Consulting Posts: 2,868
edited 2014-03-07 - 13:11:48 in Propeller 1
the PropBSC or "Propeller: BASIC Stamp Compatible" development thread
The purpose of this post is to provide details regarding a new product that has been completed to the prototype stage. A colleague of mine and I have worked together on creating a product that fits a particular gap that exists in the market while also providing additional features not currently available with other active Propeller based assemblies. We are at a point that we would like to make the design known to the forums and request for feedback regarding the current design.

Project Purpose: A mini Propeller based module that is compatible to the BASIC Stamp connection pinout and provides full circuit versatitlity to Propeller based projects. It is to provide a method of using a Propeller microcontroller in place of a BASIC stamp with absolute minimal impact to existing PCBs that accept a 24 pin BASIC Stamp module. It is also designed to be used as a core module for building your own Propeller based projects.
Project Status: Currently completed Prototype build and qualification of full functionality. After reviewing feedback, review shall be performed before continuing to production stage.

SS2_Top-Bottom-Quarter.JPG


Design Details:
  • Propeller P8X32A-M44 Microcontroller
  • 32KB EEPROM (64KB Option)
  • Micro USB for programming as well as direct power input (use your cell phone charger to power your project)
  • 5 Mhz Crystal
  • Vin of 2.5V to 12V supporting automatic step-up to step-down to provide 5V output with up to 2.5A current capability (buck boost switcher)
    • Up to 93% efficiency and greater than 80% efficient under light loads to support battery operation
    • Max 26mV ripple under load
    • Can run down to an input voltage of 1.9v, but requires a minimum of 2.1v to start up.
    • Power options are wide: 2 AA batteries, 3.7v LiPo, coin cells, solar cells, 7.2v NiCAD packs, etc
  • 3.3V available on header with 2A current capacity
    • Max 18mV ripple under load
    • Step down switcher is sourced from 5v output
  • Compatible with 3.3 and 5 volt logic systems:
    • Bi-directional level translators provide 5V I/O on P0-P15 (translators stable to 60MHZ)
    • Prop P16-P31 3.3v I/O accessible
  • 600 Mil, 24 pin, BS2 compatible headers on bottom side
  • Compatible with Parallax BS2 Carrier Boards:
    • USB and Serial Boards of Education
    • BS2 Carrier Board
    • BS2 Super Carrier Board
    • Professional Development Board
  • All Power and IOs accessible from top via 0.050" pitch headers
  • Dimensions: 1.1" W x 1.4" L x 0.55" H
  • Plans for add on boards (breakout, prototyping area, etc)
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Comments

  • WBA ConsultingWBA Consulting Posts: 2,868
    edited 2012-10-24 - 17:44:20
    This post wil be a running collection of answers to questions added to the thread.....

    How are Rx, Tx, and ATN spec'd?
    Rx and Tx are tied to P31/P30. ATN is tied to RTS of the FT230X which feeds the reset circuit for the propeller.

    How are you doing the voltage translation on the Stamp I/O pins?
    High speed bidirectional level translators, TXS0108E, tested to 60Mhz. The Prop Servo controller uses TXB series parts which are different in regards to architecture, which create limitations as you mention. TXB parts use a weak buffer with one-shot circuitry whereas the TXS parts use FET-based architectures that utilize an N-channel pass-gate transistor. From TI's docs: "The combination of an N-channel pass FET, integrated 10-kΩ pull-up resistors, and edge-rate acceleration circuits makes the TXS type translators ideal for interfacing devices or systems operating at disparate voltage levels while also allowing for simple interfacing with open-drain (O.D.) as is required in I2C, 1-wire, and MMC-card interface applications."

    My bias is to always use a 64K EEPROM and perhaps offer a 128K one as an option.
    The prototypes have a 32k, and a 64k is an option to pursue. Due to size constraints of the PCB footprint, there are limitations to the package that can be used. SDA/SCL is brought out so you can easily add secondary EEPROMs and use the onboard for a bootloader.

    Any discussion with Parallax about a PBasic interpreter for the Propeller?
    Bean's PropBASIC would be one target platform for this module to allow BASIC Stamp users a very quick migration. No plans to create another interpreter.

    I've seen a couple carrier boards that a had a stable 5V supply on board and would feed in a regulated 5V on the VOUT pin of the Stamp to power the module. Do you have a setting to accommodate that?
    Parallax's BS2 carrier, super carrier, and BOEs tie the onboard 5v regulator output to the BS2 module 5v regulator output. Our design intent was to use this module for all power needs and incoming power should be supplied at the Vin pin. (or the USB connector which supplies Vin) The "5v out pin" is an output and should not be used as an input. You can supply 3.3v to the module and it will function, however, without 5v on VccB of the translators, P0-P15 usage is undetermined (but I can test this and update this answer).

    Can you please list what advantages / improvements this has over the existing Spin Stamp ?
    Key items are: 2.5-12v input range, 5v I/O, 5v and 3.3v switching supplies for efficiency and higher current, all 32 I/Os available, USB programming (no prop plug required)

    Will it be possible to feed 3.3V in via the 3.3V terminal in order to have a really low power SLEEP mode and backup? That is usually possible with a SEPIC buck boost.
    The enable pin of the buck boost 5v switcher is brought out to the 50 mil header to effectively shutdown 5v, 3.3v, and the FTDI. Also, if Vin is less than 1.8V the 5V switcher goes into shutdown mode and will pull a maximum of 2uA. This will also disable the FTDI chip further lowering the current draw of the module. We’ve configured the 5V switcher to operate in power save mode so even with a current draw of 1mA the efficiency is over 80% in most cases. You can supply 3.3v to the module and it will function, however, without 5v on VccB of the translators, P0-P15 usage is undetermined (but I can test this and update this answer).

    Regarding the SMD power inductor behind the Prop did you test it at elevated loads/temperatures and Crystal values. Will it need a limit on crystal/pll range ?
    This has been tested and no issues have been found, including during VGA generation. Note that this is a 4 layer board with full ground and power planes.

    What is the target price point?
    The target has been to have the full module pricing at a point to place it by or under the BS2. We will be able to meet that target, but we are still resolving some pricing on a few parts to know exactly where it will be. A base version without headers looks to be possible around the $35 mark. will have a price point of $35. Full version that includes headers will be above that at an amount to cover the part cost. We will need confidence in roughly 70 orders to start production.

    Why does it have Micro USB rather than Mini USB?

    There are two main reasons for the selection of the Micro USB. One is due to board real estate. The mini-USB consumes much more real estate and in a board of this size, real estate is precious. The second is for power options. Since the design offers full power options from the USB jack, it makes sense to utilize a connector that is already a standard for powering other small devices. Micro USB is now the standard in that realm, so that was the wise choice.

    So, this is a prop board that will fit in a bread board, and all we need to add is power?
    Yes, that is correct! The width makes it appear as if it blocks some access to a breadboard, but it's height allows room for jumpers easily.

    I think I would want three to start with, when can we order?

    We are working out logistics of the startup costs to kick off production and updates will be given as frequently as possible.

    0.050" is not easy to work with, what about 0.1" headers in double row?
    The 50 mil headers were selected based upon real estate and the ability to provide as much versatility as possible. Growing the board wider would restrict it from mating with some BS2 boards.There are 0.1" headers available that will plug into every other pin allowing you to gain I/O easily. Plus, we would be offering an expansion board to mate with the module for even easier connectivity.

    If I may suggest, make a kickstarter.

    That is an option, but we are looking at other avenues that fit the business model. This will be managed by a business already in place (kickstarter works well for startups) and we are focused in addressing on initial material costs. We are looking into pre-order type solutions that will provide that and enable quick delivery for early buy-ins.

    What USB drivers, if any, need to be installed for this to be programmed?
    Standard FTDI drivers as all Parallax's boards, etc. The only difference is the Propeller Tool needs to have the reset signal set to "DTR & RTS" under "Preferences:Operations". The FT230X uses RTS for reset since it does not offer DTR. This change does not affect functionality of the Propeller Tool for other boards with DTR.

    Do you have a better pinout chart?


    See attached pics. I created a pinout chart mapped to the 50 mil headers, odd pins of the 50 mil headers to get 0.1" pitch, even pins of the 50 mil headers to get 0.1" pitch, and the bottomside 24 pin DIP configuration. Also, I listed pin descriptions.
    PinoutChart-1.jpg
    PinoutChart-2.jpg
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  • Mike GreenMike Green Posts: 22,917
    edited 2012-10-24 - 17:59:44
    How are Rx, Tx, and ATN spec'd? How are you doing the voltage translation on the Stamp I/O pins? Hopefully it's different and better than that of the S2 hacker port and the Propeller Servo Controller. I've had nothing but trouble with those. My bias is to always use a 64K EEPROM and perhaps offer a 128K one as an option. That lets you have a file system in EEPROM. 128K is about what was available on-line with a 5 1/4" floppy drive on an Apple II. Any discussion with Parallax about a PBasic interpreter for the Propeller? It could be done without access to the PIC / SX source code, but it's harder to do.
  • RobotWorkshopRobotWorkshop Posts: 2,300
    edited 2012-10-24 - 19:45:29
    It looks like you've made a nice upgrade for systems that use the 24-pin Stamps. I've seen a couple carrier boards that a had a stable 5V supply on board and would feed in a regulated 5V on the VOUT pin of the Stamp to power the module. Do you have a setting to accomodate that? If not you may want to add some pads that could be solder bridged or a trace cut to isolate that line if needed.

    I built a couple prototypes for a 40-pin version that worked out pretty well. You still have to watch the I/O pins but I had it working so it could be programmed with the same serial connection that the BS2p40 stamp used. It is an older thread now but it is still on the forum here:

    http://forums.parallax.com/showthread.php?92127-NEW-40-pin-Propeller-prototype-module-Most-hackable-yet
  • FORDFORD Posts: 221
    edited 2012-10-25 - 04:45:52
    Hi,
    Can you please list what advantages / improvements this has over the existing Spin Stamp ?

    Sorry if I'm missing something, but we use those, and I am definitely interested...

    Cheers,
    Chris
  • David BetzDavid Betz Posts: 13,480
    edited 2012-10-25 - 05:02:49
    FORD wrote: »
    Hi,
    Can you please list what advantages / improvements this has over the existing Spin Stamp ?

    Sorry if I'm missing something, but we use those, and I am definitely interested...

    Cheers,
    Chris
    I think one of its advantages is that it supports 5V I/O. Besides, the SpinStamp has been discontinued hasn't it? I looked in the Parallax store and they say "while supplies are available" and the number in stock is zero. I had considered buying a few but they seem to be gone now.
  • FORDFORD Posts: 221
    edited 2012-10-25 - 05:06:43
    Cheers David,
    I hope they are still available, we use them in a production item, albeit in low numbers.

    i would be interested to know if they have been discontinued :(

    Parallax comment here please...
  • Heater.Heater. Posts: 21,213
    edited 2012-10-25 - 05:53:35
    I have never seen or used a BASIC stamp and hardly know what one is, but that board looks like it's too good to pass up.

    I especially like the power supply and being able to extract the last drop of juice from batteries efficiently.

    I would definitely go for Mike's suggestion of the 64K or 128K EEPROM, I'll be wanting to execute Compressed Memory Model (CMM) C code from there.
  • Tracy AllenTracy Allen Posts: 6,391
    edited 2012-10-25 - 09:46:57
    That looks great Andrew. Will it be possible to feed 3.3V in via the 3.3V terminal in order to have a really low power SLEEP mode and backup? That is usually possible with a SEPIC buck boost.
  • jmgjmg Posts: 13,920
    edited 2012-10-25 - 21:38:25
    • Bi-directional level translators provide 5V I/O on P0-P15 (translators stable to 60MHZ)
    • Prop P16-P31 3.3v I/O accessible

    What Bi-directional level translators are used ?
  • WBA ConsultingWBA Consulting Posts: 2,868
    edited 2012-10-25 - 23:37:27
    Thanks for the comments and questions. I addressed items to date in post #2.
    I built a couple prototypes for a 40-pin version that worked out pretty well.

    Yes, I know that module well. When I was doing research for feasibility for my M44D40+ module, yours was one I looked at quite a bit.
  • jmgjmg Posts: 13,920
    edited 2012-10-27 - 13:54:02
    That looks like a SMD power inductor, right behind the Prop ?
    I'd be cautious about the effect that might have on the PLL stability - did you test it at elevated loads/temperatures and Crystal values.
    It may need a limit on crystal/pll range ?
  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2012-10-27 - 15:36:36
    I like it But what is the target Price point ? that 30 buck one was a Good deal ! 20 less then the BS2 ....


    farakly if you can hit under a BS2 you have just made the worlds best Stamp replacement !
  • WBA ConsultingWBA Consulting Posts: 2,868
    edited 2012-10-28 - 14:15:57
    Updated post with additional answers to the latest questions.

    Peter, yes, I believe that offering a BS2 replacement is only valid if the cost is competitive which it definitely will be. With the significant feature additions over the SS1, it would be very difficult to get it to $30 unless interest would be driving adequate volumes to reduce raw material costs.
  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2012-10-29 - 18:09:53
    Must you use Micro ? IMO Mini is more usefull as most people use it for there boards ,

    the Prop Stick is Mini . I seee your device as a sister to the Prop Stick.
  • jmgjmg Posts: 13,920
    edited 2012-10-29 - 20:38:17
    Must you use Micro ? IMO Mini is more usefull as most people use it for there boards ,

    the Prop Stick is Mini . I seee your device as a sister to the Prop Stick.

    Broadly I'd agree, and I certainly have more Mini-USB here, but the flip side is USB-Micro is the new standard for Cell Phone power/data...

    http://en.wikipedia.org/wiki/Universal_Serial_Bus

    The newer Micro-USB receptacles are designed for up to 10,000 cycles of insertion and removal between the receptacle and plug, compared to 1,500 for the standard USB and 5,000 for the Mini-USB receptacle. This is accomplished by adding a locking device and by moving the leaf-spring connector from the jack to the plug, so that the most-stressed part is on the cable side of the connection. This change was made so that the connector on the less expensive cable would bear the most wear instead of the more expensive micro-USB device

    and this

    The cellular phone carrier group, Open Mobile Terminal Platform (OMTP) in 2007 endorsed Micro-USB as the standard connector for data and power on mobile devices, and in January 2009 it was accepted by almost all cell phone manufacturers as the standard charging port for Europe.
  • WBA ConsultingWBA Consulting Posts: 2,868
    edited 2012-10-29 - 21:52:05
    Peter, although the mini-USB is still widely used in a lot of development boards, micro-USB is the standard for charging handheld devices such as phones. As such, ou will be able to find a lot of power sources in various formats with the Micro-USB connector that will work well with the module.

    JMG, spot on, that is a major factor.

    I updated post 2 with the connector question.

    thanks!
  • WBA ConsultingWBA Consulting Posts: 2,868
    edited 2012-10-30 - 11:56:21
    Was able to get some more details so that I could updated notes regarding pricing and updated thread title. This product will not be referred to as Spin Stamp 2.
  • prof_brainoprof_braino Posts: 4,312
    edited 2012-10-30 - 17:11:59
    Was able to get some more details so that I could updated notes regarding pricing and updated thread title. This product will not be referred to as Spin Stamp 2.

    So, this is a prop board that will fit in a bread board, and all we need to add is power?

    I think I would want three to start with, when can we order?
  • WBA ConsultingWBA Consulting Posts: 2,868
    edited 2012-10-30 - 18:45:36
    prof_braino, yes it drops right into a breadboard. Plug in USB and you are in business. Here are some pics showing relative size and plugged into a BOE.

    added your questions to post #2......
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  • User NameUser Name Posts: 1,451
    edited 2012-10-30 - 19:06:42
    All I've got to add is that the $29 price point is attractive. I hope sales volumes will allow you to reach it.
    Platåberget
  • jmgjmg Posts: 13,920
    edited 2012-10-30 - 19:40:40
    Do those 0.1" headers come in double row ?
    0.050" is not easy to work with, and I've seen other DIP boards add a 'second row' as an option.
    The challenge is to do it in the same PCB area, and somehow allow a choice...
  • Peter KG6LSEPeter KG6LSE Posts: 1,383
    edited 2012-10-30 - 20:11:54
    I have a name for you


    prop mini module the PMM
    or the prop Mini Stamp PMS

    or PSM prop Stamp Mini

    Peter

    Edit just saw you gave it a name .. * Head desk*
  • msrobotsmsrobots Posts: 2,909
    edited 2012-10-30 - 23:31:03
    +1 for PMS...

    I think those header are very small. But I like it. I guess I could use a couple of them in the big PDB breadboard!

    Enjoy!

    Mike
    I am just another Code Monkey.
    A determined coder can write COBOL programs in any language. -- Author unknown.
    Press any key to continue, any other key to quit

    The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT", "SHOULD", "SHOULD NOT", "RECOMMENDED", "MAY", and "OPTIONAL" in this post are to be interpreted as described in RFC 2119.
  • prof_brainoprof_braino Posts: 4,312
    edited 2012-10-31 - 04:50:02
    If I may suggest, make a kickstarter.

    Put your 29 price for the first N parts, and 35 for the latecomers, and you can log orders, and we don't pay until you get a bunch. I think you could get a bunch! Just keep the project goals as small as possible, and you'll be more likely to get folks to support it.
  • shimniokshimniok Posts: 177
    edited 2012-10-31 - 07:01:07
    Sorry if I missed it; what USB drivers, if any, need to be installed for this to be programmed? I seem to have as many programmers (and associated drivers) as I have MCUs :D
    Check out my eeZee Propeller Breakout Board

    Michael Shimniok | www.bot-thoughts.com | "It should work..."
  • MagIO2MagIO2 Posts: 2,181
    edited 2012-10-31 - 07:13:52
    I would not opt for "PMS", as it is already used as abbreviation for premenstrual syndrome.
    Actually woman having PMS is the reason for going down into the basement workshop or garage workshop. So, if it's there as well, where shall we go then?
  • WBA ConsultingWBA Consulting Posts: 2,868
    edited 2012-11-01 - 00:14:41
    Updated post #2 with additional answers.

    Pretty certain PMS won't make the cut, but we'll get the name worked in due time.

    prof_braino: yes, the project goals are simple. We are working on a pre-order strategy to set a timeline.
  • davejamesdavejames Posts: 3,967
    edited 2012-11-01 - 13:38:55
    ...RE: picture number 3 from post #20 - to quote a favorite movie of mine:

    "OOOHHHHH!!! That's just not RIGHT!!!""


    Actually, Sir, that's a nicely done board.

    I am tempted...


    Erco! Erco!! I'm tempted!! Help me - quick!!!
    Well-written documentation requires no explanation.
  • RaymanRayman Posts: 9,716
    edited 2012-11-01 - 17:28:00
    This looks very nice. Very impressive price point too. PropBasic will be a good fit for those wanting an easy transition...
    Prop Info and Apps: http://www.rayslogic.com/
  • David BuckleyDavid Buckley Posts: 6
    edited 2012-11-03 - 12:37:40
    I'd certainly like to (pre?)order a few of these.

    The 0.05 connectors with pins every 0.1 - have you got a part number on those? And is there a droolworthy pinout diagram?
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