I develop this MCP23017 Breakout Board to interface a 2×16 LCD display with any microcontroller using a standard I2C bus. Typical 2×16 displays needs at least 6 lines to work (when working in 4-byte mode); in some cases, this will be prohibited for some microcontrollers. With this board, you can control it with only two lines (I2C bus) and, by the same price, obtain a few more IO’s. I use the MCP23017 I2C expander as a bridge. This integrated circuit provides 16 IO’s over a standard I2C bus. All the pins can configure as inputs or outputs independently, and supports high speed I2C (up to 1,7MHz). Also, this device has three hardware address pins that allow connecting up to 8 devices in the same bus. The rest of the features can be seen in the datasheet.
I want to start a serie of brief articles describing the components that I usually used in my electronic designs.The first one is the DS28CM00 I2C serial number. This device is an electronic registration number that gives you an unique 64-bit serial number over I2C or SMBUS interface. This 64-bit serial number is factory lasered, so there aren’t two devices with the same number.
I use this component in a railway application, to identify the PCB’s mounted in the system. The pinout and the typical connection of this device is shown here: