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NEW - EEPROM expansion (bank switch adapter) — Parallax Forums

NEW - EEPROM expansion (bank switch adapter)

RobotWorkshopRobotWorkshop Posts: 2,307
edited 2012-11-29 18:36 in General Discussion
A while back I created a little adapter board to use as a way to expand the memory for the Propeller and also the OEM BASIC Stamp chips. The board replaces the DIP version of the EEPROM and will allow a pair of EEPROM chips to be installed instead. It has a three pin header which is used to determine which chip is addressed at address 0 and which one at address 1. By moving a jumper (or connecting a SPST switch) you can toggle between the two chips.

This has been very useful for me since you can have two complete different images available and just swap them with the flip of a switch. I've use this on a small robot that was running an OEM Stamp so I could keep two entire programs loaded and just switch between the two without reloading the Stamp each time.

Attached is a picture of the adapter board itself, the adapter installed on a DracBlade board, and also one that shows the kit. The advantage of using it here is you can switch between a couple different emulators without reloading the EEPROM each time.

This should work on most of the Propeller boards that are currently using a single DIP EEPROM chip for program storage. Boards like the DracBlade, PropRPM, PPDB (Propeller Professional Development Board), Briel PocketTerm, and others (like the other blades which names escape me). It may work on the SpinStudio or Propeller Platform depending upon what other things you install on those boards due to physical interference.

Since the Hydra and Hybrid already do some banking with the cartridge this adapter isn't for those particular boards.

The board has two .1uf caps at the supply for each memory chip and two 10K pull-ups for the chip selection. It also has two open spots so you can add pull-up resistors (1206 package) on the SDA and SCL lines in case the board you are plugging the module into is missing them and you find that you need those resistors.

I have plenty of extra boards so I wanted to offer them here. Blank boards run $1.95 or the whole kit is $3.95 The kits include machine pin headers where it plugs into the socket so it doesn't stretch out the contacts (like the square pins do) so you can easily go back to a single chip if you want.

If you'd like one (or more) of these just send me a PM or e-mail to rdoerr@bizserve.com with what you want (blank boards or kits) and location or zip code so I can get a total w/shipping.
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Comments

  • Toby SeckshundToby Seckshund Posts: 2,027
    edited 2010-11-02 02:28
    I switched the A0 pins on the board on one of my "DracBlades". The original idea was to allow for CP/M or Nascom code to be booted. As soon as I had made this Kye made it posible to boot off of a menu from the SD. I have kept it on anyway so that the Nascom option is there on a switch, for those moments when the "first computer owned syndrome" kicks in.
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-11-02 05:23
    Hello Toby,

    I saw your versions of the DracBlade (in the DracBlade thread) and it's pretty cool how you have that last version all mounted in a single case w/keyboard!

    For those that would like to switch between EEPROM chips as well they can use this adapter as a plug-in upgrade easily. I originally made this a few years ago for a small robot powered with an OEM Stamp but I found it to work well with the Propeller as well.

    Even with booting from the SD card it is still nice to have the option of switching the EEPROM chips to instantly startup in a different environment. This adapter also helps for those projects that don't have an SD card and also for the OEM Stamps which can't boot that way.

    Attached are pictures of a small Propeller module (in a BS2p40 format) and an OEM BS2p40 Stamp module both using this adapter.

    Robert
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  • Toby SeckshundToby Seckshund Posts: 2,027
    edited 2010-11-02 07:11
    That case started out as a sloping fronted box that had enough room to house a 12" by 8" PCB (the original size of a Nascom) and a PSU. Then I weakened and put a ChipBasic2 (atMega644) board in it, as it was so lost in the corner a hacksaw got to it and I just made it the size of the KBD, which was just the sloping bit.

    Then these wonderful people, here on the Prop forum, came up with all the right elements for a Dracblade running Z80 emulators-running Nascoms etc. The AVR got evicted.

    It runs on the internal Li batts for about 12 hours (idling).

    All this made one happy little bunny !
  • KaosKiddKaosKidd Posts: 296
    edited 2010-11-02 09:05
    RobotWorkshop wrote: »
    Hello Toby,

    I saw your versions of the DracBlade (in the DracBlade thread) and it's pretty cool how you have that last version all mounted in a single case w/keyboard!

    For those that would like to switch between EEPROM chips as well they can use this adapter as a plug-in upgrade easily. I originally made this a few years ago for a small robot powered with an OEM Stamp but I found it to work well with the Propeller as well.

    Even with booting from the SD card it is still nice to have the option of switching the EEPROM chips to instantly startup in a different environment. This adapter also helps for those projects that don't have an SD card and also for the OEM Stamps which can't boot that way.

    Attached are pictures of a small Propeller module (in a BS2p40 format) and an OEM BS2p40 Stamp module both using this adapter.

    Robert

    I dig your "EEPROM PLUG" method of expanding the EEPROM capability!. Nice!
    KK
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-11-03 08:51
    The documentation (in pdf form) for this board has just been attached to the first post.

    Robert
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-11-05 12:27
    Besides this adapter I made up a couple other variations. One has 4 sockets and will assign a fixed address (0,1, 2, and 3) of each chip on the adapter. It was intended to allow a board using only one EEPROM (at address 0) to allow for three extra chips.

    I was going to make an adapter for just two chips but that was kind of pointless after making the bank switch adapter since it does that by just leaving the jumper in place to set the address of the chips instead of switching them.

    Hope to hear some feedback from the kits that have already mailed out.

    Robert
  • KaosKiddKaosKidd Posts: 296
    edited 2010-11-05 13:07
    RobotWorkshop wrote: »
    Besides this adapter I made up a couple other variations. One has 4 sockets and will assign a fixed address (0,1, 2, and 3) of each chip on the adapter. It was intended to allow a board using only one EEPROM (at address 0) to allow for three extra chips.

    I was going to make an adapter for just two chips but that was kind of pointless after making the bank switch adapter since it does that by just leaving the jumper in place to set the address of the chips instead of switching them.

    Hope to hear some feedback from the kits that have already mailed out.

    Robert

    I'm interested in one of the 4 socket flavors.
    How much are you looking for?
    kk
  • ElectricAyeElectricAye Posts: 4,561
    edited 2010-11-09 20:52
    This topic was moved to the Classifieds at the request of the original poster.
  • KaosKiddKaosKidd Posts: 296
    edited 2010-11-10 12:37
    I can't wait until mine gets here...
    I'm "space deprived" as it is with two projects...

    KK
  • RavenkallenRavenkallen Posts: 1,057
    edited 2010-11-10 13:21
    Hey, nice idea. My current OS system uses two eeproms in a method similar to the one descried... I thought i was the only one who used a system like that, haha
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-11-16 11:38
    I still have some kits ready that could go right out and also plenty of the blank boards. If anyone needs a large quantity of boards let me know and I can get a discount on those.

    Robert
  • KaosKiddKaosKidd Posts: 296
    edited 2010-11-18 08:12
    Just a quick Note...
    I got my kit last night, and it's awesome...
    Great product!

    KK
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-11-29 10:36
    I just wanted to add a couple more notes about these adapter boards.

    The spots for the two resistors on the SDA and SCL lines are optional. These are for the whole I2C bus not just one chip. If the micro has internal pull-ups enabled then you don't need them. Most boards will already have whatever pull-ups are required so I would leave them open. They are in case you do need to add a pull-up resistor on the SDA or SCL lines. Some boards never had them and if you find that you do need them you can just add them on the adapter board. From what I have seen I think 4.7K or 10K is a value that a lot of people use (only if they need them).

    When installing the 4-pin heads make sure the thicker lead gets soldered into the PCB. If you find that clearance is a problem you can use one (or more) regular 8-pin DIP sockets as extension for the height to help clear parts.

    Robert
  • KPRKPR Posts: 189
    edited 2010-11-29 18:18
    got pics of the 4 socket version?
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2010-11-29 20:18
    Sure, attached is a picture that shows all of them. I also had a 4 position one setup with the sockets with two rows of two but didn't get any of those boards made yet.

    Robert
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  • KaosKiddKaosKidd Posts: 296
    edited 2010-11-30 06:09
    RobotWorkshop wrote: »
    Sure, attached is a picture that shows all of them. I also had a 4 position one setup with the sockets with two rows of two but didn't get any of those boards made yet.

    Robert

    The 4X version is slick. It's set up just like I did my proto board before the PPDB was in production... 4 EEPROMS on the same address set... just different addresses. Made life great.

    This is a slick add on for projects that need some extra space! :)

    KK
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2011-02-10 11:02
    I've used these adapters on each one of the small 40-pin DIP modules below with excellent results. Even without bank switching you can just leave the jumper in one spot and use it to add a second I2C memory device.

    http://forums.parallax.com/showthread.php?92127-NEW-40-pin-Propeller-prototype-module-Most-hackable-yet&highlight=bs2p40

    http://forums.parallax.com/showthread.php?114299-Carrier-PCB-for-OEM-BS2p40-Stamp-chip.&highlight=bs2p40

    http://forums.parallax.com/showthread.php?94916-SX48-40-pin-DIP-full-kit-and-PCB-available.&highlight=bs2p40

    Robert
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2011-04-07 09:41
    There are still plenty of the blank boards available as well as full kits for the two chip version shown in the first post of the thread.

    Robert
  • WhitWhit Posts: 4,191
    edited 2011-05-11 14:00
    Neat idea Robert! I missied this when it originally posted (don't know how).

    I found it with your comment on the RoboProp Board.
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2011-07-12 09:59
    I expect to bring these boards to the next UPENE show coming up in August. If you can't wait until then just send me a PM and I'll be glad to sell some ahead of time.

    Robert
  • RobotWorkshopRobotWorkshop Posts: 2,307
    edited 2011-10-16 13:18
    These are still available in case anyone would like one. Just send me a PM.

    Robert
  • Oldbitcollector (Jeff)Oldbitcollector (Jeff) Posts: 8,091
    edited 2012-11-29 18:36
    These (PCB) are now available from Propellerpowered.com thanks to Robert!

    http://propellerpowered.com/shop/?page_id=1315

    Jeff
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