Hyperdisplay default font usage problems

Components & Accessories Displays
1

Hello, I’m using the EPAPER_420 display and going off this tutorial: https://learn.sparkfun.com/tutorials/ev … ng-windows

I have been able to draw lines, pixels and shapes on the epaper display using the SparkFun_ePaper_Arduino_Library however I can’t get fonts written. This tutorial doesn’t make it clear to me if the default font stuff works out of the box or if there are some missing pieces that need to be done.

In hyperdisplay.h it has this section within class hyperdisplay : public Print … public:

// Printing
        virtual size_t write(uint8_t val);                                      	// This is the implementation of write that is inherited from print.h, left as virtual to be implementation specific
		#if HYPERDISPLAY_USE_PRINT		
        	virtual void getCharInfo(uint8_t character, char_info_t * pchar);       // The pchar pointer argument points to a valid char_info_t object that the function must fill out with the right values
		#endif	/* HYPERDISPLAY_USE_PRINT */
        void setTextCursor(int32_t x0, int32_t y0, wind_info_t * window = NULL);
        void resetTextCursor(wind_info_t * window = NULL);

And there are two incomplete example programs in the hyperdisplay library from within the Arduino IDE.

Once I #include Sparkfun_ePaper_420.h and hyperdisplay.h and create an EPAPER_420 object instance named myEpaper, how do I call these setTextCursor() and print() functions? myEpaper.setTextCursor(x,y) doesn’t work. I don’t understand if I must first implement my own inherited class to use the default font or if there is already an out-of-the-box way.

2

Hi distro inferno,

The ePaper display is a SparkX product so the scope of our support for this is very limited. That said, I have a few quick pointers that might help you troubleshoot this issue. First, depending on the microcontroller you are using with the ePaper display, the default font may not work since it requires the microcontroller to have “avr/pgmspace.h” defined in the Arduino core. If you are using, say, an ESP32 Thing Plus, that does not have that defined so the default font does not work out of the box. [This issue in the HyperDisplay GitHub repository has a great response from the engineer for a deep dive on that problem and a fix.

Now, if you are using a microcontroller that does have “avr/pgmspace.h” defined, it might be that the text is defaulting to the same color as the background so try adjusting either the background color or the color of the text and that might help.

If none of these suggestions fix the issue or get you pointed in the right direction, can you please include a few more details in your reply. First, which microcontroller are you using with the display? Next, can you please include your code in your response so we can possibly identify what the issue is?](Alternative Font Sizes · Issue #2 · sparkfun/SparkFun_HyperDisplay · GitHub)