arduino heltec e-ink epd uno adafruit-gfx drawing graphics display e-paper arduino-library esp32 esp8266 samd21 wireless-paper vision-master

Heltec E-Ink Modules

Third-party Arduino Library for Heltec E-Ink Displays.
Run-time drawing, using Adafruit-GFX.

Read the API

Vision Master
Wireless Paper
SPI Displays
Drawing
Troubleshooting
Installation
- Arduino
- PlatformIO
Acknowledgements

Vision Master

See Getting Started with Vision Master for instructions on setting up Arduino IDE or PlatformIO.
(Important platformio.ini config)

Model	Driver Class	Front Image	Rear Image	Resolution (px)
E213	`EInkDisplay_VisionMasterE213`			250 x 122
E290	`EInkDisplay_VisionMasterE290`			296 x 128

#include "heltec-eink-modules.h"

EInkDisplay_VisionMasterE213 display;

void setup() {
    display.print("Hello, World!");
    display.update();
}

void loop() {}

Wireless Paper

See Getting Started with Wireless Paper for instructions on setting up Arduino IDE or PlatformIO.
(Important platformio.ini config)

Hardware Version	Driver Class	Flex Connector Label	Front Image	Rear Image
V1.1	`EInkDisplay_WirelessPaperV1_1`	(not visible)
Original (V1.0)	`EInkDisplay_WirelessPaperV1`	FPC-7528B

#include "heltec-eink-modules.h"

EInkDisplay_WirelessPaperV1_1 display;

void setup() {
    display.print("Hello, World!");
    display.update();
}

void loop() {}

A low power state is available for the whole board (18μA while sleeping).

SPI Displays

Identification

Pay attention to the model name: you will need it to use the library.

1.54 Inch

Model Name	Flex Connector Label	Colors	Screen Protector	Resolution (px)	Fastmode (partial refresh)
DEPG0154BNS800	FPC-7525	Black, White	Red Tab	152 x 152	Yes
DEPG0150BNS810	FPC-8101	Black, White	Red Tab	200 x 200	Yes
GDEP015OC1 ^?	HINK-E0154A05-A2	Black, White	Blue Tab	200 x 200	Yes

2.13 Inch

Model Name	Flex Connector Label	Front Image	Rear Image	Colors	Screen Protector	Resolution (px)	Fastmode (partial refresh)
DEPG0213RWS800	FPC-7528B			Black, White, Red	Red Tab	250 x 122	No
QYEG0213RWS800	FPC-7528			Black, White, Red	Red Tab	250 x 122	No

2.9 Inch

Model Name	Flex Connector Label	Colors	Screen Protector	Resolution (px)	Fastmode (partial refresh)
DEPG0290BNS800	FPC-7519 rev.b	Black, White	Red Tab	296 x 128	Yes
DEPG0290BNS75A	FPC-750	Black, White	Red Tab	296 x 128	Yes
GDE029A1	SYX-1553	Black, White	Blue Tab	296 x 128	Yes

Wiring

Warning: in some cases, connecting directly to the display will cause damage!
See your boards's wiring page for specific information:

// Specify your wiring when declaring the display
DEPG0150BNS810 display(dc, cs, busy);

// Optional: specify SDI and CLK (ESP32 & SAMD21* only)
DEPG0150BNS810 display(dc, cs, busy, sdi, clk)

_{See here for limitations of SAMD21G18A wiring}

Should I use `update()` or `DRAW()`?

The DRAW() operation allows for RAM saving tricks (paging). Required for older boards, configurable for new boards. More info about DRAW() here.

/* 
  Use DRAW() if:
   - you need to support Arduino Uno R3 / Mega 2560, or
   - you desperately need to save RAM
*/
    DRAW(display) {
        display.print("Hello, ");
        dispaly.print("World!");
    }


// Otherwise, you're free to use update() instead
    display.clearMemory();
    display.print("Hello, ");
    display.print("World!");
    display.update();

Drawing

Shapes and Text

Drawing operations come from the Adafruit GFX library You'll find a full list of supported commands in the API. Check out the examples folder to see them in action. Alternatively, the official adafruit-gfx tutorial is a good place to start.

Fonts

The library comes with a selection of custom fonts. You can create more with truetype2gfx.
See the Fonts example.

Images

As decided by the Adafruit library, the ancient "XBitmap" is the format of choice for pre-rendered graphics. Luckily, GIMP maintains good support for it. If you need a hint on how to use it, I have thrown together a tutorial on preparing XBitmap images.

SD card

It is possible to load and save .bmp images, using a cheap SD card SPI adapter. Read more

Fast Mode (Partial Refresh)

E-Ink displays generally take several seconds to refresh. Some displays have an alternative mode, where the image updates much faster.

The trade-off is that images drawn in fast mode are of a lower quality. The process may also be particularly difficult on the hardware. Use sparingly.

Not all displays support fast mode.

Call fastmodeOn() to enable.
Call fastmodeOff() to return to normal.

_{* Technically, this mode is not a true "partial refresh", as the whole display image is updated.}

Troubleshooting

Double-check your wiring
On breadboard, or header pins, it is easy to be one row out.
Make sure to use a level-shifter, if needed.

Double-check your constructor

// Make sure to use the correct class for your display model
EInkDisplay_WirelessPaperV1_1 display;

// SPI displays: make sure your pins are set correctly
DEPG0150BNS810 display(dc, cs, busy);

Take a look at the examples, and the API
Some commands might not work the way you would expect. If unsure, double check.
Disconnect and Reconnect
If the display has been used incorrectly, it can get "stuck".
Remove all power from the display and Arduino for 5 seconds.
Make sure your build enviorment is configured correctly
- Vision Master
- Wireless Paper

Installation

Arduino

Library can be installed to Arduino IDE with Sketch -> Include Library -> Add .Zip Library.., or through the built-in Library Manager.

PlatformIO

Available through the built-in library registry, or alternatively, can be installed by extracting the Zip file to the lib folder of your project.

For Vision Master and Wireless Paper boards, your platformio.ini file needs to be correctly configured.

Acknowledgements

Display information referenced from both official Heltec sources, and GxEPD2.
Drawing functions provided by GFX Root, which itself is a stripped down version of Adafruit GFX.
A bundled version of SdFat is used with some platforms.
TJpg_Decoder is bundled with certain examples.

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Third-party Arduino Library for Heltec E-Ink displays