RS232 SPI Click Board™

How Does The RS232 SPI Click Board™ Work?

The RS232 SPI Click Board™ uses two ICs - MAX3100 and MAX3232. MAX3100 serves as UART interface to the SPI/MICROWIRE compatible interface converter. In the same time, MAX3232 device enables RS232 SPI click to meet the requirements of TIA/EIA-232-F and also provides the electrical interface between an asynchronous communication controller and the serial-port connector. The charge pump and four small external capacitors allow operation from a single 3-V to 5.5-V supply.

The RS232 SPI Click Board™ Uses an SPI™/MICROWIRE™ interface for communication with the host microcontroller (µC). Then, the MAX3100 is responsible for conversion from synchronous serial data from a microcontroller to asynchronous, serial-data communication port such as RS-232, RS-485, IrDA. In this case the RS232 protocol is used. The MAX3100 includes a crystal oscillator and a baud rate generator with software-programmable divider ratios for all common baud rates from 300 baud to 230k baud. The transmitter section accepts SPI/MICROWIRE data, formats it, and transmits it in asynchronous serial format from the TX output. Data is loaded into the transmit buffer register from the SPI/MICROWIRE interface. The MAX3100 adds start and stop bits to the data and clocks the data out at the selected baud rate.

A software- or hardware-invoked shutdown lowers quiescent current to 10µA, while allowing the MAX3100 to detect receiver activity. An 8-word-deep first-in/first-out (FIFO) buffer minimizes processor overhead. This device also includes a flexible interrupt with four maskable sources, including address recognition on 9-bit networks. Two hardware-handshaking control lines are included (one input and one output).

Because of the features contained in its modules, the RS232 SPI click can be used for handheld instruments, UART in SPI systems, small networks in HVAC or Building control, battery-powered systems, PDAs, notebooks and many more.

The RS232 SPI Click Board™ offers a selection between 3.3V and 5V operation, with the onboard SMD jumper, labelled as VCC SEL. This allows both 3.3V and 5V MCUs to be interfaced with this Click board™.

SPECIFICATIONS

PINOUT DIAGRAM

This table shows how the pinout of the RS232 SPI 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
Device shut down	SDN	2	RST	INT	15	INQ	Interrupt Output
SPI Chip Select	CS	3	CS	RX	14	NC
SPI Clock	SCK	4	SCK	TX	13	NC
SPI Data OUT	SDO	5	MISO	SCL	12	NC
SPI Data IN	SDI	6	MOSI	SDA	11	NC
Power Supply	3.3V	7	3.3V	5V	10	5V	Power supply
Ground	GND	8	GND	GND	9	GND	Ground

ONBOARD SETTINGS AND INDICATORS