An organic LED display interface is demonstrated on this project with an ARM7 microcontroller displays and analog clock face on OLED low power screen containing an 18-bit color range.
Through the SPI port, the project is using DS3234S RTC IC that is interfaced to ARM7 Atmel AT91SAM7S64 microcontroller. Using light sensor TSL256 is another interesting feature of the clock where the adjusting of display brightness is enabled according to the ambient light level. The clock is dimmed in dark environment while the brightness is high in bright room since 16 brightness levels are allowed by OLED.
The OLED display is 128x128 pixel full-color used as an output by the ARM7 microcontroller while the clock face is a raster image of analog clock face with a dedicated real-time clock IC is maintained for the time. The OLED display has integrated controller and memory and is well suited to battery-powered applications when compared to equivalent LCD since OLED display only powers the pixels that are lit while all pixels in LCD are backlit and light is selectively blocked for some of them.