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Driving the LCD - share your experience

Anthocyanina

Hi! So, I've been working on the software for this challenge and have reached the point where i need to figure out the LCD. The datasheet has a character map and and the addresses for the position of each character. I don't have much experience with driving LCDs so I'm struggling with where to start. Have any of you figured out the LCD yet? 

I found a couple threads on the arduino forum that talk about this display, with people saying you could use the HD44780 libraries, or similar to drive it. I'll be trying that with an arduino board first, but still would like to hear about your experience with this display so far. 

Thank you!

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  • I just created a first version of a Raspberry Pi python library for the RW1063 LCD controller of the MIDAS Display.
    I will update as I add new functionality to the library. You are free to use it however you want, without any guarantee, I haven't tested it thoroughly yet.

    https://github.com/javagoza/lcdrw1063

  • in reply to javagoza

    oh wow, that's amazing! thank you for sharing. i think i might end up using it in this challenge. i tried writing a library myself, but i can barely handle loops and ifs in software! :P

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  • in reply to Anthocyanina

    You and anyone else are welcome to use that library.

    In any case, after having studied the data sheet and the controller manual well, I think that any library that works for the HD44780 could work for you.

    Aspects to configure:

    • I2C communication. It should allow the address to be configured to any of these values: 0x3C, 0x3D, 0x3E or 0x3F
    • Data length 8 bits, this is important, since many libraries that work with parallel communication only implement 4-bit communications
    • Configuration of the 2-line display, although the display has 4 lines, it is configured as two 2-line displays working in parallel with two LCD drivers.
    • Only write mode is allowed for I2C, instruction write, and memory write operations can be used. It is not possible to use read operations, the display only asserts with ACK, it does not send data via I2C.
    • The DDRAM memory addresses of the four display lines are 7 bits: 0x00, 0x40, 0x14, 0x54
    • The CGRAM memory addresses for custom characters are 6 bits, from 0x00 to 0x56, each 5x8 bit character you need to send 8 bytes to configure it.

    Some of the aspects that I want to improve in my implementation are:

    • Add digital port for controlling the Chip Select (CS) state from the library.
    • Add a digital port to turn the LCD backlight on/off.
    • Add configuration of number of columns and rows.
    • Property for setting cursor at specific row and column position. cursor_pos = (0, 5)
    • Encapsulate private methods.

    Finally, I must remind myself that the purpose of this challenge is to test the Hammond enclosure, that this is an accessory aspect and although I am having a great time, the box is calling me in my dreams.

  • in reply to javagoza

    actual dreams? i want to experiment with makeshift magnetic connectors to interface with the outside world. i tried with a piece of polycarbonate, and it went so bad i ended up actually having a bit of a nightmare about the actual enclosure breaking and falling apart when i tried the magnetic connector in an actual dream, hahahaha

  • in reply to Anthocyanina

    I have ordered a capacitive sensor, the cheapest I have found, I want to do tests to see if it is capable of detecting my fingers behind the lid. Good idea about the magnetic sensor, it could be put on one of the sides.

  • in reply to Anthocyanina

    Some time ago I built a magnetic quadrature encoder with magnetic reed switches.

    This encoder can be hidden on the internal lateral sides of the enclosure.

    VenTTracker #07 - Adjusting the window sensor

  • in reply to javagoza

    oh, i meant a magnetic connector, like these

     image

    my idea was to have ferromagnetic contacts, melting through the plastic to make a waterproof seal, and then use a cable attached to tiny magnets to get signals into and out of the box, more than the 2 we can get out of it with the included connector. but my experiments with a polycarbonate piece i had were not successful at getting a waterpoof seal or even a good melting! I'll be showing that in a blog :P

  • in reply to Anthocyanina

    LoL, I hadn't understood anything.

    I have yet to make a hole for a waterproof microphone connector. But I don't have the tool to make the hole precisely, so I keep thinking about it to see if I can do something with a Dremel tool without making a mess.

  • in reply to javagoza

    I'm going to get a pair of USB 3 connectors, not for USB but to have 9 pins to use for various things on the outside. it has a simple circular shape, with 2 flat edges, like the connector we got with the kit, but a simple circular hole should be easy enough to make with a large enough drill bit

  • in reply to Anthocyanina

    For acrylic plastic I have had good results with a drill bit with a sharp tip 60º or less, soaping it well with dish soap, so that it does not get hot and at low speed, without pressing, allowing the chip to come out. And with a block of wood on the other side so that it doesn't break when the tip comes out of the plastic by the other side.

    But I can't find anything that works for the Dremel for an 18.5 mm hole that I have to make. I might try it with a soapy file and manual sandpaper.