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Parallel Display (Hitachi) HD44780U...standard - Page 2 — Parallax Forums

Parallel Display (Hitachi) HD44780U...standard

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  • hmlittle59hmlittle59 Posts: 404
    edited 2016-04-25 21:47
    Thanks Chris and Hal,

    Just saw your emails. Have to do some shipping will chking within the hour. But a quick check does look like that's the way it is hooked up..

    thanks again



  • hmlittle59hmlittle59 Posts: 404
    edited 2016-04-26 18:59
    Hello Chris, Hal, and All,

    Changed out displays and the viewing is no better. Changed the 10 K ohms fixed resistor off ground and no change. These displays were cheap a while back, so I'll try and get a Black on Yellow and see how they look...At lease the data is bright enough to get the Code convert over to the Parallel Display......Anyway.

    Learning the two (2) Commands has been changeling. The output format (Brackets []) is not used the same as the Serial. I've got both Serial and Parallel running the same Data to the screen and the formatting of code is different and only one (1) command at a time. NO, (LCD ON, LCD Home, LCD Clear Screen) at one time like with the Serial Display. OUCH!!!
    With LCDCMD & LCDOUT I'm about 75% of the way on how to use one or both during Data output. Once the Light comes on in my head (and stays ON), things should move quicker. Now I'm having to go back to the examples and re-read them. Also the Formatting to the Screen itself is not always working the way I'm thinking it should work. OFF-SETS (from HOME) does not always come out correctly to the display. Stumbling their. The Serial Display is my example as I'm converting the coded to Parallel and ODD data is popping up and then clears once the program bounces back to the more STABLE code in RAM Slot 1. All changed data seems to be saved/updated, but the random data needs to be cleared up. Slot one (1) Code is stable, 5 more to go...WOW!!!
    I had planned a month....looks like it may be 2 months.

    PS: Chris, in one example the Code has a "PAUSE 0" and in the Editor Help file it has a "PAUSE 1", should it be either or "PAUSE 5" Like the Serial?

    Thanks
  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    Howard,

    I'm not sure what example you're referring to. I did want to mention though that, while you don't have LCD Clear anymore, all you need to do is send a single-byte using LCDCMD to do the same thing.
  • Hello Chris,

    The "Help" file 2.5.4 example (LCDOUT) under Init_LCD and (LCDCMD) under Init_LCD, shows different values. Just not sure what to use. Also, looking at those example (AGAIN), I realized why I was having formatting issues. I was using (LCDHome + 13) instead of (Lcddram + 13) as an example for doing OFFSET. Don't quite understand why though. That's helping with a lot of my current problems. Like I said earlier, some of this will get a bit tricky with splitting routines.

    Please let me know when you find out if I need to go back and add those "PAUSE" statements after those two (2) commands. Some don't have either. Just a bit confusing.

    Thank again

  • Chris SavageChris Savage Parallax Engineering Posts: 14,406
    edited 2016-04-27 15:13
    Howard, you're not just converting from serial back to parallel. The serial backpack does more than just convert from serial to parallel on the display. The parallel display works so much differently. It has a data bus and two registers. Each register is designed to accept commands or data. And then some commands require multiple bytes to accomplish. The serial backpacks make this stuff easy and mostly transparent to the user, so it's easy to forget that the underlying display is a bit more complex. The LCD commands on the BS2p-series make it easier to handle the parallel interface and timing of the lines on the display, but you're still talking to the display in its native format.
  • Hello Chris,
    I started with a OEM BS2e + Shift Reg. chip and got the program/concept to working(without the user friendly front end). Then I thought that I would have to relearn Assembly Language (C-64 was old) with a different MC + Parallel Display and get that (concept) to working again. That's when I talked to someone at Parallax Tech. 3 or 4 years ago (Davis or David not really sure now), but he told me that I could use this OEM BS2p chip when I was ready to start this project. This has allowed me to do it all. I've already decided to change from only convert to combined displays because it seems to be going so well. Can always go back and strip one out as needed.
    Got a second burst of energy last night til 2:00 am and now have only 3 RAM Slots to go. One of those slots currently has no video output (yet). Plenty of RAM space to added if needed. One of the others 2 will have to have a 1 for 1 exchange of video command codes. That was half completed and working when I called it quits this morning. The other Slot has the same calculations done in 5 Slots to maintain really time accuracy (ex.:program setting at "Main Menu" per user). I might be able to get away with 4 and add a save to EEPROM RAM or DS1302 and "GET" as needed. I use "GET" now for configuration data and some Flags SET/Reset.
    Back down to 1 month before completion...The data from the DS1302 was almost a Copy and Paste of the Serial formatting. Wow, that was one of the main ones that had me worried.

    The Serial Display does seem to be a bit quicker. Could be these old eyes though. Can see a lag of letters from screen to screen on the Parallel, not so on the Serial. Will try and redo the clearing of a location(s) first before printing their. That may help with that affect. New Video should be here soon (Black on Yellow).

    Thanks again for the feedback
  • Hello All,

    Wow, formatting error in the "AM/PM" mode. The first letter would not show up unless buffered with a space on both sides in the data field and then the "M" was shifted off view. Wow, up to 2:30 am this time and still couldn't fix it. Anyway.

    Back to regular job for now.
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