Recent content by JKIM

OK, I am guessing the constructor doesn't use the USBHost parameter, but the constructor is defined this way to force the caller to have already created a USBHost object as a safeguard?

OK, I think the USBHIDInput override for operator bool() is responsible for the driver claiming boolean: class USBHIDInput { public: operator bool() { return (mydevice != nullptr); } https://github.com/PaulStoffregen/USBHost_t36/blob/master/USBHost_t36.h#L523

I am trying to understand the general architecture of the HID device drivers in the USBHost_t36 library. I didn't find any overview docs on the library, so I am researching it from the code. Specifically, I don't understand how the relationship between different objects is established, like...

MIDI uses a current loop. I think you need to tap off the Thru signal after the opto-isolator.

It should be located above: https://forum.pjrc.com/threads/54345-ILI9341_t3-font-editor?p=191271&viewfull=1#post191271

Sounds good! The LVGL font spec is here: https://github.com/lvgl/lv_font_conv/blob/master/doc/font_spec.md

Thanks for this! It would be awesome if this also supported the LVGL font format ( https://lvgl.io/tools/fontconverter ) or an intermediate format to work with the existing LVGL converter.

I am using a custom board (with FlexIO2), but it looks like the standard T4.1 should have enough exposed consecutive pins on FlexIO3 starting with AD_B1_00 for the 16bit bus, plus 4 pins for D/C, WR, and CS. The example I started with is here: https://community.nxp.com/thread/501529 But using...

I have used the FlexIO with 16bit parallel interface, based on the mculcd demo from the NXP SDK. It works well, although I did have to tweak it a bit.

I had good luck with umm_malloc: https://github.com/rhempel/umm_malloc

OK, I have gotten somewhat further. I was able to get ThorsSerializer working with SdFat (Teensy4 beta, using SDIO) for serialization at least. I had to change SdFat to use custom class names so that it didn't conflict with stdlib, and then adapt ThorsSerializer to use the SdFat streams...

Yes, that is definitely an option. My member types are fairly simple, ints, pointers and vectors, so a library is maybe a bit of overkill in most cases. But I wanted to check for recommendations before I go too far down that rabbit hole. By the time I handle the various data types and the...

Thanks Paul. I am trying to accomplish the serialization of a large amount of application data (MIDI) from an external RAM chip onto an SD card for long term storage and data exchange. Preferably in a human readable/portable format, like JSON. The external RAM is larger than the RAM banks in...

I have been researching on the best way to serialize large objects for storage on the SD card of Teensy 4. Specifically ones that don't have to store a DOM into a temporary variable, before serialization. I have tried Boost, Cereal, ArduinoJson and ThorsSerializer. I think for my purposes...

Is there a recommended approach to use SdFat along with existing newlib stdio functions? I was able to get SdFat to work by renaming all of the classes and members to something other than the stdio equivalents, but this creates other problems for classes using stdio types...