it8951

[it8951](../README.md) › [Globals](../globals.md) › ["it8951"](../modules/_it8951_.md) › [WAVEFORM](_it8951_.waveform.md) # Enumeration: WAVEFORM Waveform mode used when updating the display. Further information is available in the [mode declaration](https://www.waveshare.com/w/upload/c/c4/E-paper-mode-declaration.pdf). **`export`** ## Index ### Enumeration members * [A2](_it8951_.waveform.md#a2) * [DU](_it8951_.waveform.md#du) * [DU4](_it8951_.waveform.md#du4) * [GC16](_it8951_.waveform.md#gc16) * [GL16](_it8951_.waveform.md#gl16) * [GLD16](_it8951_.waveform.md#gld16) * [GLR16](_it8951_.waveform.md#glr16) * [INIT](_it8951_.waveform.md#init) ## Enumeration members ### A2 • **A2**: = 6 *Defined in [it8951.ts:373](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L373)* The A2 mode is a fast, non-flash update mode designed for fast paging turning or simple black/white animation. This mode supports transitions from and to black or white only. It cannot be used to update to any graytone other than black or white. The recommended update sequence to transition into repeated A2 updates is shown in Figure 1. The use of a white image in the transition from 4-bit to 1-bit images will reduce ghosting and improve image quality for A2 updates. **Usage:** Fast page flipping at reduced contrast **Ghosting:** Medium **Typical update time:** 120ms ___ ### DU • **DU**: = 1 *Defined in [it8951.ts:301](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L301)* The direct update (DU) is a very fast, non-flashy update. This mode supports transitions from any graytone to black or white only. It cannot be used to update to any graytone other than black or white. The fast update time for this mode makes it useful for response to touch sensor or pen input or menu selection indictors. **Usage:** Monochrome menu, text input, and touch screen/pen input **Ghosting:** Low **Typical update time:** 260ms ___ ### DU4 • **DU4**: = 7 *Defined in [it8951.ts:386](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L386)* The DU4 is a fast update time (similar to DU), non-flashy waveform. This mode supports transitions from any gray tone to gray tones 1,6,11,16 represented by pixel states [0 10 20 30]. The combination of fast update time and four gray tones make it useful for anti-aliased text in menus. There is a moderate increase in ghosting compared with GC16. **Usage:** Anti-aliased text in menus / touch and screen/pen input **Ghosting:** Medium **Typical update time:** 290ms ___ ### GC16 • **GC16**: = 2 *Defined in [it8951.ts:314](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L314)* The grayscale clearing (GC16) mode is used to update the full display and provide a high image quality. When GC16 is used with Full Display Update the entire display will update as the new image is written. If a Partial Update command is used the only pixels with changing graytone values will update. The GC16 mode has 16 unique gray levels. **Usage:** High quality images **Ghosting:** Very low **Typical update time:** 450ms ___ ### GL16 • **GL16**: = 3 *Defined in [it8951.ts:325](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L325)* The GL16 waveform is primarily used to update sparse content on a white background, such as a page of anti-aliased text, with reduced flash. The GL16 waveform has 16 unique gray levels. **Usage:** Text with white background **Ghosting:** Medium **Typical update time:** 450ms ___ ### GLD16 • **GLD16**: = 5 *Defined in [it8951.ts:359](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L359)* The GLD16 mode is used in conjunction with an image preprocessing algorithm to update sparse content on a white background with reduced flash and reduced image artifacts. It is recommended to be used only with the full display update. The GLD16 mode supports 16 graytones. If only the even pixel states are used (0, 2, 4, … 30), the mode will behave exactly as a traditional GL16 waveform mode. If a separately-supplied image preprocessing algorithm is used, the transitions invoked by the pixel states 29 and 31 are used to refresh the background with a lighter flash compared to GC16 mode following a predetermined pixel map as encoded in the waveform file, and reduce image artifacts even more compared to the GLR16 mode. For the AF waveform, it is assured that the GLD16 waveform data will point to the same voltage lists as the GL16 data and does not need to be stored in a separate memory. **Usage:** Text and graphics with white background **Ghosting:** Low **Typical update time:** 450ms ___ ### GLR16 • **GLR16**: = 4 *Defined in [it8951.ts:341](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L341)* The GLR16 mode is used in conjunction with an image preprocessing algorithm to update sparse content on a white background with reduced flash and reduced image artifacts. The GLR16 mode supports 16 graytones. If only the even pixel states are used (0, 2, 4, … 30), the mode will behave exactly as a traditional GL16 waveform mode. If a separately-supplied image preprocessing algorithm is used, the transitions invoked by the pixel states 29 and 31 are used to improve display quality. For the AF waveform, it is assured that the GLR16 waveform data will point to the same voltage lists as the GL16 data and does not need to be stored in a separate memory. **Usage:** Text with white background **Ghosting:** Low **Typical update time:** 450ms ___ ### INIT • **INIT**: = 0 *Defined in [it8951.ts:288](https://github.com/gnzzz/IT8951/blob/604332d/lib/it8951.ts#L288)* The initialization (INIT) mode is used to completely erase the display and leave it in the white state. It is useful for situations where the display information in memory is not a faithful representation of the optical state of the display, for example, after the device receives power after it has been fully powered down. This waveform switches the display several times and leaves it in the white state. **Usage:** Display initialization **Ghosting:** N/A **Typical update time:** 2000ms