Expand 12 Click is a compact add-on board that contains a multi-port I/O expander. This board features the MAX7300, a general-purpose I/O expander providing remote I/O expansion for most MCU’s families from Analog Devices. The MAX7300 comes in a 28-port configuration and allows easy addition of I/O through a standard I2C serial interface. Each port is user-configurable to either a logic input or logic output, capable of sinking 10mA and sourcing 4.5mA. In addition, seven ports feature configurable transition detection logic, which generates an interrupt upon change of port logic level. This Click board™ provides a simple solution when additional I/Os are needed while keeping interconnections to a minimum in system monitoring applications, industrial controllers, portable equipment, and many more.

Expand 12 Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

Expand 12 Click as its foundation uses the MAX7300, a general-purpose input/output (GPIO) expander from Analog Devices, now part of Analog Devices. This port expander is a simple solution when additional I/Os are needed while keeping interconnections to a minimum, particularly great for system monitoring applications, industrial controllers, portable equipment, and others. The MAX7300 comes in a 28-port configuration, which can be configured to any combination of logic inputs and logic outputs, and default to logic inputs on Power-Up.

Any I/O port can be configured as a push-pull output (sinking 10mA, sourcing 4.5mA) or a Schmitt-trigger logic input. Each input has an individually selectable internal pull-up resis­tor. Additionally, transition detection allows seven ports (from port 24 up to port 30) to be monitored in any maskable combina­tion for changes in their logic status. A detected transition is flagged through a status register bit, as well as an interrupt pin (port 31) if desired.

Expand 12 Click communicates with MCU using the standard I2C 2-Wire interface to read data and configure settings with a maximum frequency of 400kHz. Besides, it also allows the choice of the least significant bit of its I2C peripheral address by positioning the SMD jumpers labeled as ADDR SEL to an appropriate position marked as 1 and 0. This way, the MAX7300 provides the opportunity of the 16 possible different I2C addresses by positioning the SMD jumper to an appropriate position.

This Click board™ can operate with both 3.3V and 5V logic voltage levels selected via the VCC SEL jumper. This way, it is allowed for both 3.3V and 5V capable MCUs to use the I2C communication lines properly. However, the Click board™ comes equipped with a library containing easy-to-use functions and an example code that can be used, as a reference, for further development

• Interface: I²C
• Compatibility: mikroBUS™
• Dimensions: 57.15 x 25.4mm
• Input Voltage: 3.3V or 5V
• Port Sink Current: 10mA
• Port Source Current: 4.5mA
• Number of I/Os: 28 pins
• Operating Temperature Range: Min. -40°C, Typ. +25°C, Max. +125°C

• Schematic
• MAX7300 Datasheet
• mikroSDK
• GitHub