OM13500A LCD demo board
Created: Dec 03, 2014
No description available.
The OM13500A is a Liquid-Crystal Display (LCD) demo board, which is used to illustrate the PCA9620 and PCA8537 segment driver. These components drive signals for any static or multiplexed LCD containing up to eight backplanes, 46 segments and 352 elements. PCA9620 communicates via a two-line bidirectional I2C-bus and PCA8537 can be easily connected to a microcontroller by either the two line I2C-bus (PCA8537AH) or a three-line bidirectional SPI-bus (PCA8537BH). Both PCA9620 and PCA8537 feature an internal charge pump for on-chip generation of the LCD driving voltages.
The board is controlled by an LPCXpresso microcontroller board, which contains the LPC1115 Cortex M0 controller. LPCXpresso is a low-cost development platform available from NXP. The software consists of an enhanced, Eclipse-based IDE, a GNU C compiler, linker, libraries, and an enhanced GDB debugger. Both LCD drivers offer the option of using the internal or an external oscillator. This can be set using the configuration registers. If the internal oscillator is used, the oscillator signal is available at connector "CLK". If an external oscillator signal is used, this can be supplied to the LCD driver using this connector "CLK". Switch SW1 is used to select which of the three power supply options is being selected (5V_BAT, 5V_USB or 5V_EXT). The 5V output of the switch is used to supply the backlight of the display. Furthermore, the voltage labeled "3V3_LPCXPR" is generated with an additional regulator, IC5. The 3.3V is used to supply the microcontroller board LPCXpresso, and to supply the logic VDD of the LCD driver.
This board was developed in order to provide a low cost tool to engineers, wishing to demonstrate and evaluate these LCD drivers, and to get hands-on experience with writing code for these drivers. The code written using this board can serve as an example for the final application that enables rapid prototyping.