The UART Mux Click is a Click board™ that switches the UART pins (RX and TX) from the mikroBUS™ to one of the four available outputs. It employs the SN74LV4052A, a Dual 4-Channel Multiplexer and Demultiplexer from Texas Instruments. It is designed for 2-V to 5.5-V VCC operation. Some of the typical applications for the SN74LV4052A include signal gating, chopping, modulation or demodulation (modem), and signal multiplexing for analog-to-digital and digital-to-analog conversion systems, which makes it ideal for multiplexing the UART pins from the mikroBUS™ to the multiple outputs.

The UART Mux Click is supported by a mikroSDK compliant library, which includes functions that simplify software development.

UART Mux Click is equipped with the SN74LV4052A, a Dual 4-Channel Multiplexer and Demultiplexer, from Texas Instruments. Two control pins are used to switch to one of four available outputs, from a single UART input, from the mikroBUS™. Control pins labeled as A and B, are routed to the mikroBUS™ and can be operated by both 3.3V and 5V MCUs. The fourth control pin is labeled as EN pin, and it is used to enable the internal multiplexing switches of the IC, when is set to a HIGH logic level (it is active HIGH). A and B pins are routed to CS and PWM pins of the mikroBUS™ respectively. The active low Inhibit (INH) tri-state all the channels when high and when low, depending on the A and B inputs, one of the four independent input/outputs is connected to the UART communication pins. INH pin is routed to the RST pin on the mikroBUS™.

The ultra-low leakage current ensures that there is no signal interference from the inputs that are not selected by the A and B pins. A low crosstalk also ensures that the signal on one channel remains clean of interferences caused by other channels. This ensures a reliable operation of the IC and the Click board™ itself.

The output signals can be connected via the 2x4 pin headers. Besides RX and TX pins, every output also has dedicated VCC and GND pins avalilable, so that user can easily route multple devices with this Click board™. Independent power supply input allows the user to work with a wide range of signal amplitudes, depending on the application requirements, as long as the power supply stays within the limits.

More information about the SN74LV4052A can be found in the attached datasheet. However, the Click board™ comes equipped with a library that contains easy to use functions and a usage example that may be used as a reference for the development.

UART Mux Click offers a selection between 3.3V and 5V operation, with the onboard SMD jumper, labeled as PWR SEL. This allows both 3.3V and 5V MCUs to be interfaced with this Click board™.

• Interface: GPIO, UART
• Compatibility: mikroBUS™
• Dimensions: 57.15 x 25.4mm
• Input Voltage: 3.3V or 5V

• Schematic
• SN74LV4052A Datasheet
• mikroSDK
• GitHub