This is a demonstration of a ILI9341 LCD using SPI connected to a STM32F072B Discovery board. My purpose for this project was to work in a redicilously resource constrained environment, and to that end it works quite well.
| Board | LCD |
|---|---|
| PB5 | DISP_DC |
| PB6 | SPI_CS |
| PB15 | SPI_MOSI |
| PB14 | SPI_MISO |
| PC13 | PI_SCK |
| PB12 | DISP_RESET |
| PA9 | USART1_TX |
| PA10 | USART1_RX |
| 3V | VCC |
| 3V | LCD |
| GND | GND |
The demonstration draws the following:
- Draws red, green and blue to the screen pixel-by-pixel
- Draws text pixel-by-pixel
- Draws text using a faster process with a background
- Draws a counter from 000-999 using pre-rendered text (this is the fastest way to draw text)
- Draws a right triangle using vertical line, horizontal line and arbitrary line functions
Full screen writes take about 600ms if dealing with arbitrary pixels. The bottleneck here is the speed of memory writes, a buffer transfered via the DMA repetitively (to draw a pattern or solid color) will alow for ~3fps.