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SSD1327 Grayscale OLED Display driver for libDaisy Nim wrapper

The SSD1327 is a 128x128 grayscale OLED controller with 16 gray levels (4-bit per pixel). Unlike monochrome displays, each pixel can display shades from black (0x0) to white (0xF).

Features:

128x128 resolution
16 grayscale levels (4-bit per pixel)
SPI transport only (no I2C variant)
Compact framebuffer: 2 pixels per byte (8192 bytes total)
Compatible drawing API with other OLED drivers

Hardware Notes:

Common in higher-end OLED modules
Buffer format: packed 4-bit pixels (upper nibble = even pixel, lower = odd pixel)
Default grayscale level: 0xF (white)

Example - Basic usage:

import nimphea
import nimphea/dev/oled_ssd1327

var display = initSSD1327Spi(128, 128)
display.fill(false)
display.setGrayscale(0x8)  # Medium gray
display.drawCircle(64, 64, 30, true)
display.setGrayscale(0xF)  # White
display.drawPixel(64, 64, true)
display.update()

Example - Grayscale gradient:

# Draw gradient from black to white
for x in 0..<128:
  let gray = uint8(x div 8)  # 0-15
  display.setGrayscale(gray)
  display.drawLine(x, 0, x, 127, true)
display.update()

Imports

nimphea, spi

Types

SSD1327Spi128x128 {.importcpp: "SSD1327Spi128x128".} = object: Source Edit
SSD1327SpiConfig {.importcpp: "SSD1327Spi128x128::Config", bycopy.} = object transport_config* {.importc: "transport_config".}: SSD13274WireSpiTransportConfig: Source Edit
SSD1327SpiPinConfig {.importcpp: "daisy::SSD13274WireSpiTransport::Config::pin_config", bycopy.} = object dc* {.importc: "dc".}: Pin reset* {.importc: "reset".}: Pin: Source Edit
SSD13274WireSpiTransportConfig {.importcpp: "daisy::SSD13274WireSpiTransport::Config", bycopy.} = object spi_config* {.importc: "spi_config".}: SpiConfig pin_config* {.importc: "pin_config".}: SSD1327SpiPinConfig: Source Edit

Consts

GRAYSCALE_BLACK = 0x00'u8: Black (minimum brightness) Source Edit
GRAYSCALE_DARK = 0x04'u8: Dark gray (25% brightness) Source Edit
GRAYSCALE_LIGHT = 0x0C'u8: Light gray (75% brightness) Source Edit
GRAYSCALE_MEDIUM = 0x08'u8: Medium gray (50% brightness) Source Edit
GRAYSCALE_WHITE = 0x0F'u8: White (maximum brightness) Source Edit

Procs

proc Defaults(config: var SSD13274WireSpiTransportConfig) {. importcpp: "#.Defaults()", header: "daisy_seed.h", ...raises: [], tags: [], forbids: [].}: Source Edit
proc drawCircle(display: var SSD1327Spi128x128; x0, y0, radius: int; on: bool = true) {....raises: [], tags: [], forbids: [].}: Draw a circle outline using midpoint circle algorithm

Parameters:

x0, y0 - Center point

radius - Circle radius in pixels

on - true to draw with current grayscale, false for black

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proc drawLine(display: var SSD1327Spi128x128; x0, y0, x1, y1: int; on: bool = true) {....raises: [], tags: [], forbids: [].}: Draw a line using Bresenham's algorithm

Parameters:

x0, y0 - Start point

x1, y1 - End point

on - true to draw with current grayscale, false for black

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proc drawPixel(display: var SSD1327Spi128x128; x, y: int; on: bool = true) {. ...raises: [], tags: [], forbids: [].}: Draw a single pixel with current grayscale level

Parameters:

x, y - Pixel coordinates (0-based)

on - true to draw with current grayscale, false for black

Note: Use setGrayscale() to change the drawing color before calling this.
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proc drawRect(display: var SSD1327Spi128x128; x, y, w, h: int; on: bool = true) {. ...raises: [], tags: [], forbids: [].}: Draw a rectangle outline

Parameters:

x, y - Top-left corner

w, h - Width and height

on - true to draw with current grayscale, false for black

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proc fill(display: var SSD1327Spi128x128; on: bool = true) {....raises: [], tags: [], forbids: [].}: Fill entire display with a color

Parameters:

on - true for white (0xF), false for black (0x0)

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proc fillRect(display: var SSD1327Spi128x128; x, y, w, h: int; on: bool = true) {. ...raises: [], tags: [], forbids: [].}: Draw a filled rectangle

Parameters:

x, y - Top-left corner

w, h - Width and height

on - true to draw with current grayscale, false for black

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proc height(display: SSD1327Spi128x128): int {.inline, ...raises: [], tags: [], forbids: [].}: Get display height in pixels (always 128) Source Edit
proc setGrayscale(display: var SSD1327Spi128x128; level: uint8) {....raises: [], tags: [], forbids: [].}: Set the current grayscale drawing level

Parameters:

level - Grayscale value 0x0 (black) to 0xF (white)

Example:

display.setGrayscale(0x0) # Black display.drawCircle(32, 32, 10, true) display.setGrayscale(0x8) # Medium gray display.drawCircle(64, 64, 10, true) display.setGrayscale(0xF) # White display.drawCircle(96, 96, 10, true)
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proc update(display: var SSD1327Spi128x128) {....raises: [], tags: [], forbids: [].}: Send framebuffer to display hardware Call this after drawing to make changes visible Source Edit
proc width(display: SSD1327Spi128x128): int {.inline, ...raises: [], tags: [], forbids: [].}: Get display width in pixels (always 128) Source Edit

Templates

template initSSD1327Spi(width, height: static[int]; dcPin: Pin = newPin(PORTB, 4); resetPin: Pin = newPin(PORTB, 15); sclkPin: Pin = newPin(PORTG, 11); mosiPin: Pin = newPin(PORTB, 5); nssPin: Pin = newPin(PORTG, 10)): untyped: Initialize SSD1327 OLED via SPI

Parameters:

width, height - Display dimensions (only 128x128 supported)

dcPin - Data/Command pin (default: PB4)

resetPin - Reset pin (default: PB15)

sclkPin - SPI clock pin (default: PG11)

mosiPin - SPI MOSI pin (default: PB5)

nssPin - SPI chip select pin (default: PG10)

Returns: Initialized display instance

Example:

var oled = initSSD1327Spi(128, 128) oled.setGrayscale(0xF) # White oled.fill(false) oled.update()
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