The I2C and serial display driver provides easy operation of a standard 20 x 4 LCD Text display. It requires only a 5v power supply and the two data connections for either mode, freeing up pins on your processor. Many useful text formatting functions are provided and also the ability to put together custom characters into memory which can be called off as required. There is a 64 byte FIFO buffer to ensure a minimum of delay in writing to the display.
A single jumper link is used to select Serial or I2C mode. When the jumper is present the module is in serial mode. When the jumper is removed the module is in I2C mode. The mode jumper is only checked as part of the power-up sequence, so make sure the display is off before changing modes. If you change the link position while the module is powered, nothing will change until next time you switch on.
Because the I2C communications operate faster than the display can accept data, all commands and text you send to the display are placed in the FIFO (First In, First Out) buffer. This data is sent to the display as fast as it will accept it. The FIFO is 64 bytes in length and the number of free bytes can be returned in either mode. When sending lots of text to the display, you should check the number of free bytes so you don't overflow the buffer. If the buffer does overflow, the excess bytes are ignored. The FIFO buffer exists in Serial mode too, but at 9600 the display is fast enough and you are unlikely to need to check it.
The LCD05 controller is the new generation LCD display driver and adds additional features to our previous LCD03 driver while being fully compatible in both software and pin-out.
- Display - 20 characters per row, 4 rows
- Voltage - 5VDC only required
- Current - 75mA typ. with backlight on
- Modes - I2C or 9600 baud Serial
- Keypad - Automatic scanning of a 3x4 matrix keypad
- Custom characters - up to 8 custom characters easily defined
- Backlight defaults off, and can be turned on under software control