1. Introduction

This is a driver for ED060SC4 800x600 e-ink display panel manufactured by Prime View. Note that this driver uses a direct connection to the panel from the processor; it does not use a separate controller chip between the processor and the panel.

To use the driver, you need to be able to control the following signals from your processor:

Gate driver: SPV, CKV, GMODE. Source driver: CL, LE, OE, SPH, D0-D7. Power supply: +-15V, +22V, -20V, digital Vdd

The file "example_schematics.png" shows how to connect the signals to e.g. a STM32L151 microcontroller. It also includes an example circuit for providing the panel supply voltages.

Note that the larger panels (such as the 800x600) consist of multiple segments with separate gate driver signals. These can be daisy chained as shown in the example schematic.

Please see here for more information on the panel: http://essentialscrap.com/eink/

2. Frame buffer emulation

Because there is not enough memory to store a full frame buffer on the processor, this driver emulates a frame buffer by storing the display data in blocks. It will buffer up to EINK_NUMBUFFERS blocks and then write them to the screen. The following #defines control the buffering. Larger numbers will result in faster drawing, but also use more RAM on the processor:

define EINK_BLOCKWIDTH 20 // Width of a single block in buffer

define EINK_BLOCKHEIGHT 20 // Height of a single block in buffers

define EINK_NUMBUFFERS 40 // Number of blocks to buffer

After drawing your images, you should flush the buffers using the following command:

#include <ed060sc4.h>
gdispControl(GDISP_CONTROL_FLUSH, 0);

The buffers are also flushed whenever you turn the display off using:

gdispSetPowerMode(powerOff);

3. Display clearing and writing waveforms

This driver does not know the official Prime View waveforms for driving the display, mostly because those are trade secrets and not publicly available. Instead, it uses reverse engineered waveforms that are mostly functional.

The following #defines control the waveforms:

define EINK_BLINKCLEAR TRUE // Clear to opposite color first

define EINK_CLEARCOUNT 10 // Number of sweeps to clear the display

define EINK_WRITECOUNT 4 // Number of sweeps when writing to display

Increasing the clearcount and writecount can improve contrast, but will also slow down the drawing and use more power.

4. Clock speeds

Because the driver bit bangs the display, the clock frequency of the processor is quite significant. This is controlled by EINK_CLOCKDELAY variable. Set it so that the delay is atleast 50 nanoseconds.

5. Support for other kinds of panels

Most of the Prime View panels should work using this driver, but only ED060SC4 has been tested so far. Some points of consideration:

• Some displays may use 4 bits per pixel. The driver currently assumes 2 bits per pixel.
• Larger displays may require some other way of daisy chaining than shown in the example schematics.