Relay 5 Click Board™

Product Code: MIKROE-5675

How Does The Relay 5 Click Board™ Work? The Relay 5 Click Board™ is based on three J1031C3VDC.15S, a high-current single-pole double-throw (SPDT) signal relays from CIT Relay and Switch, controlled in a very simple way through a port expander from NXP Semiconductors, the PCA9538A. The J1031C3VDC.15S relay is well known for its reliability and durability, high sensitivity, and low coil power consumption housed in a small package with PC pin mounting. Despite its size (12.5x7.5x10 millimeters (LxWxH)), the J1031C3VDC relay can withstand up to 2A and 125VAC/60VDC maximum. These relays are designed to easily activate their coils by relatively low currents and voltages, making them a perfect choice that any MCU can control. Besides, their durability is impressive, with over 5M of mechanical life cycles. The contact configuration of the J1031C3VDC.15S is a single-pole double-throw (SPDT), meaning it has one pole and two throws. Based on the default position of the pole, one throw is considered normally open (NO) while the other is normally closed (NC), which is, in this case, its default position.

When the coil is energized, it will attract the internal switching elements similar to a switch. For this purpose, the Relay 5 Click has three terminals for each relay that are adequately labelled. In addition, every relay has its status LED (REL1-3) for visual status presentation. As mentioned, the relays are not directly driven by the host MCU but by the PCA9538A, a low-voltage 8-bit I/O port with interrupt and reset from NXP Semiconductors. This I/O expander provides a simple solution when additional I/Os are needed while keeping interconnections to a minimum. The Relay 5 Click uses the PCA9538A and 2-Wire I2C interface to communicate with the host MCU. The PCA9538A supports a fast mode of up to 400KHz of clock frequency. The I2C Address can be selected via the ADDR SEL jumpers, with 0 selected by default. The expander can be reset over the RST pin with active LOW, thus setting the registers to their default values without the need to power it off. The Relay 5 Click Board™ can operate with either 3.3V or 5V logic voltage levels selected via the VCC SEL jumper. This way, both 3.3V and 5V capable MCUs can use the 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. SPECIFICATIONS Type Relay Applications Can be used for controlling high-power applications On-board modules J1031C3VDC.15S - high-current single-pole double-throw (SPDT) signal relays from CIT Relay and Switch PCA9538A - low-voltage 8-bit I/O port expander from NXP Semiconductors Key Features Three electro-mechanical relays, low power consumption, reliable switching, high current, high sensitivity, SPDT configuration, relay activity indicators, long mechanical life, control over the I/O port expander, and more Interface I2C Compatibility mikroBUS Click board size L (57.15 x 25.4 mm) Input Voltage 3.3V or 5V PINOUT DIAGRAM This table shows how the pinout of the Relay 5 Click Board™ corresponds to the pinout on the mikroBUS™ socket (the latter shown in the two middle columns). Notes Pin Pin Notes NC 1 AN PWM 16 NC Reset RST 2 RST INT 15 NC NC 3 CS RX 14 NC NC 4 SCK TX 13 NC NC 5 MISO SCL 12 SCL I2C Clock NC 6 MOSI SDA 11 SDA I2C Dlock Power Supply 3.3V 7 3.3V 5V 10 5V Power Supply Ground GND 8 GND GND 9 GND Ground ONBOARD SETTINGS AND INDICATORS Label Name Default Description LD1 PWR - Power LED Indicator LD2-LD3 REL1-R