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Ozindfw

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  1. OK, I think understanding is beginng to dawn... I'm trying to keep the basic design really simple. I have spare pins to accomodate this, but I'm thinking this may be a different flash option. I'll need to gather some more display datasheets to see if there is a standard pinout. I need to do this for the 2X8 header as well. If there's no convention tehn everything in this class is going to be a custom cable. No matter that happens the single controller/simple board case is going to drive selections and the other stuff will be optional. I'm not going to let it raise base cost or drive much additional complexity. I'm trying to simplify the design and reduce base costs, not add to it. I need to think on this some more. Backlight power consumption is a non-issue. If the board can't handle it then you just handle it off board for those rare cases. IF I do anything, I'm not planning on a Launchpad BoosterPack - I'm looking at a design that has the same footprint as a standard 16X2 display (36 X 80 mm)
  2. Ah. This seems reasonable. If they were displaying the same content this should be (relatively) easy. Conceptually and from an active hardware standpoint, no. It would add a lot of board area for the additional connectors and would require some more thought about how to differentiate the displays. What I was planning on doing was just to passing the same command bytes to the display. I'll need to give this some thought. I thought about this initially and figured I'd leave it for down the road if I needed it.
  3. I guess I need to go pull more datasheets. All I've found so far use the same pin number assignments for the 8X2 and 16 X 1 connector. I really like your design. Somehow I missed it when looking for what others have done. This is my quandry. My current draft uses a pair of TI TXB0104s. They are $3 alone. Where are you finding 3.3V displays for $5? Most I've seen start at $10.
  4. Yes, because all I'm planning on doing is passing bytes to the interface. I'm only using the 16X2 footprint.
  5. I'm looking for comments and suggestions to make this more generally useful. I have a pile of surplus character line LCDs based on the Hitachi HD44780 chipset. There are oodles of these available surplus, and really cheap, like $2 cheap. The probelm I see for most modern MCUs is that the LCDs are usually 5V I/O (at least for the surplus parts) parallel and chew up a lot of I/O slow so they require a bit of code to poll the display or timed delays to insure reliable operation. I'm not too motivated to reinvent the wheel, but all the options I've found seem to miss a lot. I've seen the Adafruit board, but it's hard-coded at 5V (deal killer) and the 16X1 connector (inconvenient for displays with the 8X2 connector.) I started thinking about a launchpad boosterpack that would provide a 3.3V SPI serial interface, but realized that it was too specialized and really didn't meet my needs. What I'm noodling about now is a 'backpack' board that is fairly universal. It would match the standard 16X2 character board mechanical footprint and provide the 16X1 header interface connector AND the 8X2 connector that is the other dominant standard usually used on 2X24 character dispalys. It would also provide: A simple, sequential version of the HD44780 command structure - send the bytes, the board worries about handshaking and timing. SPI I2C Serial UART (Logic or RS232 Levels) logic levels from 1.8V to 5V - selectable backlight current control (settable by component value selection) dimming by MCU command contrast by MCU command on board regulator for board on board regulator forLCD including backlight most options selected by hardware jumpers ASYNC serial autobaud I can fit all this on the board without a problem, but too many features results in too much cost and kills the advantage. A lot of this is optional BoM stuff - as in 'don't need RS-232 - don't stuff this.' I don't see any reason to: have more than one interface operational at a time - SPI or I2C or UART use variable resistors. use through hole components for other than connectors (would it be better to have backlight current setting as leaded resistors?) Use anything other than a 2X? 0.1" header for the external interface so:no DB9 for serial power on interface connector pins, not a seperate connector no screw terminals So, what do you think?
  6. Never mind. Just spotted what I need on the wiki. Not sure why I didn't see it the first time. D'oh The link to the file inteh wiki is malformed - in has a spurious "f" on the end. I can't edit it to correct it. http://doc.43oh.com/BoosterPack:Universal_Color_LCD Link under hardware revisions is: http://doc.43oh.com/File:Jdt1800-v2.pngf should be http://doc.43oh.com/File:Jdt1800-v2.png Oz (in DFW)
  7. I'm looking for documention on the V1.2 board - specifically schematic and parts list. I've rummaged around the forum and read this thread, but haven't spotted any. I have the board, but need to stuff it (with parts.) Oz (in DFW)
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