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    ILI9341_t3/ILI9341_t3n implementing const reads and static SPI class

    Thank you so much! I'll definitely have a look at your code. Casting away const won't work because it would involve detrimentally modifying an existing cross platform graphics library I wrote (https://honeythecodewitch.com/gfx) :( Also I've run into scary issues doing that due to certain...
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    ILI9341_t3/ILI9341_t3n implementing const reads and static SPI class

    Sorry, to clarify what I'd like to see is this: readRect(int16_t x, int16_t y, int16_t w, int16_t h, uint16_t *pcolors) const; The way to make const would be like I said, to move all that internal state and SPI code to statics inside template classes, and then instance those *templates* with CS...
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    ILI9341_t3/ILI9341_t3n implementing const reads and static SPI class

    I've run into a problem with the optimized ILI9341 driver implementations by Paul S. and Kurt E. The issue is this: Reading from the display can't be done with a const class reference because the methods like readRect() are not marked const, which creates some encapsulation issues. It's also a...
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    ARM Cortex M7 MIMXRT1062 alternative?

    Fair enough. :) I've been studying the datasheets side by side. I'm about as good at that as I am at reading sheet music, which is to say I'm terrible at it, but eventually get it if I squint. I'm much better with code. ha. I guess I'll be the first to try it. It's at least the same processor...
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    ARM Cortex M7 MIMXRT1062 alternative?

    I'm looking to fab a design I made with the teensy, but the exact processor used in the Teensy 4.1 is out of stock at digikey, and I don't see it on mouser at all. I was wondering if I can use this in the alternative? I don't know much about ARM, except that their processors vary in...
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    Highly optimized ILI9341 (320x240 TFT color display) library

    Thank you, I'll definitely take a look at that. I did figure out that the procs are different, but right I'm going to support the Teensy 4.1 which I own and can test. Supply problems prevent me from getting previous versions at the moment.
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    Highly optimized ILI9341 (320x240 TFT color display) library

    This is a pretty old thread, so apologies for revisiting it, but it's still linked at at the ILI9341_t3 library on GitHub via the README I've been digging through the driver code, because seeing it in the wild helps me to understand the manual when I finally encounter it. Well, I've been...
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    Optimized ILI9341_t3 driver, technical DC questions regarding implementation

    That's not quite what I'm wondering. I know what DC and CS do. I'm asking if there's some sort of hardware optimization for wiring the DC line to one of the hardware CS pins on the Teensy, because the comment suggests as much. Paul S. I'm sure knows the answer.
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    Optimized ILI9341_t3 driver, technical DC questions regarding implementation

    Background - why I'm even asking: I wrote the htcw_gfx library which is a cross platform graphics library that's a bit more high level than Adafruit and TFT_eSPI, but not quite LVGL. It does however, support anti-aliased TrueType vector fonts, JPG, alpha-blending, indexed color matching for...
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    Prang Pro: A MIDI score sampler on the Teensy

    Prang is a MIDI score sampler originally developed on an ESP32S3. I've ported it to the Teensy 4.1, though it will probably work with other teensies with small modifications. It basically allows you to map individual tracks from a MIDI file to be triggered by keys on your MIDI controller...
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    Doing "SDA reads" on a Teensy (SPI hack certain TFT controllers use)

    Yeah, I understand the pitfalls of it pretty well. And I realize that using the arduino SPI.h facilities is a performance tradeoff compared to going to the registers directly. Here's the thing. htcw_gfx has no knowledge of things like SPI, I2C, or any sort of display hardware. No idea. It has...
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    Getting std::chrono to work with the Teensy

    I'll tell you now, I use The STL sparingly when I'm working with little machines. Heap fragmentation is an absolute killer, and then there are issues of certain 8-bit procs not fully supporting it for obvious reasons. To that end I have reimplementations of vectors, hash tables, circular...
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    Getting std::chrono to work with the Teensy

    Paul, thanks for the information! I definitely will use your approach when I don't need it to the microsecond. In the application I wrote for this, the timing is critical, so I'll try your method and compare what I get, see if it's "good enough" - it's hard for me to know offhand because it's...
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    Getting std::chrono to work with the Teensy

    That's awesome advice for hobbyists, which I am not. I am evaluating the Teensy for the possibility of using Arm Cortex processors in future professional endeavors like I currently do with other platforms. > , & just dive into the capabilities provided by & for the Teensy. It sounds like...
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    Getting std::chrono to work with the Teensy

    Thanks! I'll bear that in mind, though I really only use the STL on IoT sparsely, and when I do use chrono it's because I want a cross platform way to do precision timing. It works on most platforms I've tried out of the box. Teensy is the first one where I've had to do anything significant to...
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    Getting std::chrono to work with the Teensy

    Good to know that's accurate enough! I had no idea.
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    Getting std::chrono to work with the Teensy

    I'm not sure where to put this, so here goes. I hope it's useful to someone. I just figured out how to resolve the linker error with _gettimeofday() and to implement that function such that it will actually make std::chrono be able to do its job properly as well as link properly. volatile...
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    Doing "SDA reads" on a Teensy (SPI hack certain TFT controllers use)

    Yeah, with htcw_gfx of course, you can write to an intermediary bitmap, but it's more work, and kind of bleh when all you want to do is draw some vector fonts anti-aliased to the screen. Furthermore, while the teensy has 1MB of SRAM it's still prohibitive to require say, a 160kB frame buffer to...
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    Doing "SDA reads" on a Teensy (SPI hack certain TFT controllers use)

    KurtE, I'd prefer to use htcw_gfx due to TrueType support, and the fact that I am the maintainer and I use it professionally, so I can add features and improve things as needed. It currently works with the Teensy, but the SDA reads are the trick. I don't know how to set that up. I would be...
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    Doing "SDA reads" on a Teensy (SPI hack certain TFT controllers use)

    rcarr, Oh I see. Then I misunderstood *you*. I apologize. I'd rather them not have to do a hardware hack but I'll keep it mind.
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    Doing "SDA reads" on a Teensy (SPI hack certain TFT controllers use)

    You misunderstood me. I'm not interested in creating a display controller, and if I was I would not use SDA reads. I need to know how to do this in software with the teensy. I felt I was clear in my post, but maybe you could tell me what part threw you so I can clarify? Basically I need to...
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    Doing "SDA reads" on a Teensy (SPI hack certain TFT controllers use)

    Display controllers like the ST7789 and ST7735 and I think some other controller families have a strange facility they use for reading the frame buffer back off of the device (almost necessary for realistically alpha blending and anti-aliasing) They basically use the MOSI line as a MISO line as...
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    Add raw message handler/callback to usb midi host and state.

    There's a complication with the MIDI host library for the Teensy (USBHost_t36) such that it won't easily integrate with other 3rd party libraries that deal with MIDI messages. The reason being is A) you have to hook a dozen or so callbacks to get the complete message stream B) it's...
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    USB Host on Teensy 4.1, no power, no data, two brand new boards

    Thank you so much! I've been tearing my hair out on google, on reddit, everywhere I could find to try to run this problem down. It had occurred to me that it might be software controlled, but I dismissed it, because I hadn't seen that before (even my PC doesn't work that way) and because who...
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    USB Host on Teensy 4.1, no power, no data, two brand new boards

    I ordered a teensy specifically for the USB host capabilities. It didn't work. I ordered a second teensy, again specifically for the USB host capabilities. Unfortunately repeating the same thing over and over again is not yielding different results and I'm tired of throwing money at something...
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