NEW: SDRAM Module for Propeller Platform
Nick McClick
Posts: 1,003
Jazzed has designed an awesome 32MB SDRAM expansion module for the Propeller Platform, I have a few available now & more are coming soon;
Three versions are available;
There's a little more info on the project page, & a lot more info on the SDRAM expansion forum thread.
Let me know if you have any questions!
Three versions are available;
- SDRAM: includes 32MB of SDRAM & a microSD card slot
- SDRAM+TV: Includes 32MB of SDRAM, microSD card slot, 2xPS/2 Connectors, a pre-programmed ATTiny for PS/2 - I2C translation, and composite video out
- SDRAM+VGA: Includes 32MB of SDRAM & VGA video out. Does not include a microSD card slot
There's a little more info on the project page, & a lot more info on the SDRAM expansion forum thread.
Let me know if you have any questions!
Comments
Nice work
The SDRAM only board doesn't include any through hole parts (everything is surface mount).
The SDRAM+VGA board just needs the VGA connector added on
The SDRAM+TV board needs the ATTiny 8-pin dip socket, PS/2 connectors, and the RCA jack.
Parts are included.
@Sapieha - Thanks! This is jazzed's creation, I can't take any credit, but he's made an awesome board.
@Nick, thanks for all your patience with me Warning! This is just the beginning.
@David, I've attached a parts-list with notes on the options on the project page. Now if I can only figure out how to make the normal parts-list link correctly to it
Today VGA+SDCARD is not supported, but VGA can be used without SDCARD of course. VGA does need a connector and few more parts.
For people wanting to use VGA and SDCARD, another solution will come but it will be more expensive since it will rely on a second Propeller - this means the buffer and VGA signal generation will be completely off-loaded from the main CPU.
It is unlikely that C3 will ever be able to use this SDRAM module - efficiently.
A fully integrated Propeller+SDRAM solution is planned, but it will never be as flexible as the Propeller Platform solution.
Cheers.
--Steve
The board(s) look great and another fine addition to the propeller platform.
Ray
You can get email when more product is available if you sign up for "Tell Me!" on the product page. http://www.gadgetgangster.com/359
Thanks.
I know that jazzed had been working on the TinyTwoWire module, which overlaps some of the functionality -- the keyboard/mouse logic using an ATTiny (84 vs. 85).
Did I miss something about future availability, or a new design, or something else?
@Ding-Batty,
The SDRAM only version that is left can have TV with an RCA connector and a few SMD resistors (270, 560, 1.1K). The all-in-one boards are still available if demand justifies more production. Anyone interested in the all-in-one boards should leave a note here or email Nick.
Regarding new design(s): a new module that has SDRAM+TV/AV standard with 2 RCA connectors (minus Keyboard/Mouse) will be shipping soon. I'll leave the details of that up to Nick.
There are other product-line additions coming later. One of the most interesting is the single-board PropellerPC designed for a small enclosure. I'll post more on the PropellerPC in a blog/thread later.
The first thing I did was to remove the headers already mounted, and put on new ones like the long-tail female headers used for some Arduino shields (in fact, those are exactly what I used: 4 8-pin headers plus one more split into two 4-pin pieces), and put then in my "preferred" holes on the board.
My first bit of good luck was that the board worked after that modification.
Next, I got the SdramTest.spin code working so that I could make sure the board worked. This was a little harder than I expected: Between starting with an older version of the test and cache code, and trying to find a copy of FullDuplexSingleton, I thrashed around a bit. I finally found a copy of the right version of FullDuplexSingleton in an earlier copy of the SdramTest zip files in the project thread, but the file is not currently in the SdramTest.zip file on the Gadget Gangster website.
Good news for me: with the right serial driver, and the right version of the cache code and test code, the SDRAM access on the board passed with flying colors.
Next problem: test the microSD card. So I got a copy of Kye's newest SD3.01 Fat16/32 driver code. Now, I know the SDRAM pins are not the usual ones, so I went to find out exactly how the Propeller pins map to the SD card socket. Hmmm.... not really documented anywhere obvious, that I could find -- not in the most recent schematic (which Steve said was not up-to-date). I went hunting for test code, and finally found the pin definitions in some of the code in the ZOG thread.
More good news: SD card access seems to work fine as well. So I didn't kill the card (at least not those portions), and I can move on to the next round of experiments.
Just to memorialize the pin assignments on the board, in case anyone else is looking:
To be thorough, since the TV resistors and TV-audio capacitors are present on the board, these seem the signals used for the TV video and audio (I have not tested these, and I hope if I am wrong I will be corrected):
TV video pins: P20..P22
Audio pin: P23
Thanks guys -- now I can have some real fun!
We have been running ZOG on the C3 and the SDRAM board. A release will be available soon.
The demos are a little thin right now, but with a release you'll find a TvText driver, a version of Bagger's Half-Height TV driver (Tv2Text) that allows more lines per screen. I'm working on Keyboard/Mouse drivers as well. Do you have the AVR KEYBD/MOUSE chip and connectors?
David Betz will post a release candidate of ZOG at some point in the near future.
Thanks.
--Steve
- Module pictures
- A list of Propeller pins usage
- Parts list
- Parts placement drawing
- The original A1 schematic as .pdf
- An updated SdramTest* package
*SdramTest software requires BST or Homespun compiler, but can be used with Propeller Tool with #ifdef code selection removed. I will not be held hostage by missing tool features!Ray
This particular design is being superceeded by 2 new boards:
1. TinyTwoWire for KB/Mouse currently available
2. A new SDRAM/TV board which Nick is now building.
Separating the functions of the all-in-one module into two boards makes sense
for users who do not want the Keybd/Mouse ports.
The original design can still be had if you want it - I will build it myself
to your specification today if you like. I have enough parts for 4 boards.
I thought about a using a SDRAM for the DracBlade but feeble mindedness ( and idleness) got me nowhere, again
I just assumed ...