Devantech USB to UART, I2C, SPI, serial adapter (USB-ISS)

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Price

$22.50

Adapter for communicating to I2C, SPI and serial buses from a USB port. Output pins may alternatively be configured as general purpose digital input/output and analog inputs.

SKU:

R348-USB-ISS

Manufactured by

Devantech

United Kingdom

Tabs

Overview

This Devantech USB-ISS serial adapter communicates with I2C, SPI, and serial buses. It can be powered via USB type-B connector, or else configured for general-purpose digital input/output and analog input. Removing the “power link” jumper allows the module to be powered via a 3.3V source. The module can supply up to 80mA at 5.0V for external circuitry from a standard USB port. The device is compatible with Windows, Mac OS X, and Linux-based operating systems; drivers are required if it’s being operated under Windows; in other operating systems, the module will automatically appear in the system’s device tree.

Note: the R348 is a drop-in replacement for the R286 which has been retired by the manufacturer

Dimensions

Features

USB Powered
USB to I2C
I2C at 20kHz to 1MHz (clock stretching supported)
USB to SPI
SPI at 24kHz to 3MHz
USB to Serial UART
Serial UART at 300bps to 3Mbps
Mounting holes
Horizontal or vertical pin options

Downloads

Files

Attachment	Size
3D IGES CAD Model	1.97 MB
Windows Driver (v3)	6.35 KB

Specs

Pin Out

Power Link - Remove for 3.3v operation.

I/O	SPI	Serial	I2C	I2C+Serial
3.3v / 5v	3.3v / 5v	3.3v / 5v	3.3v / 5v	3.3v / 5v
I/O4	SDI	I/O4	SDA	SDA
I/O3	SCK	I/O3	SCL	SCL
I/O2	SDO	Tx	I/O2	Tx
I/O1	/CE	Rx	I/O1	Rx
0v Ground	0v Ground	0v Ground	0v Ground	0v Ground

Bootloader Link - Fit link for Bootloader mode

Voltage Supply

Use the "power link" jumper to operate from 5V, or remove it for 3.3V
The USB-ISS can operate from 3.3V or 5V. With the LEDs on, it takes approximately 20mA. From a standard 100mA USB port, when operating at 5V, the USB-ISS module can supply up to 80mA to external devices. When the jumper is removed, a 3.3V regulator supplies the power. This regulator is capable of 50mA, so when running at 3.3V approximately 30mA is available to external devices. Do not apply your own voltage to this pin.

LEDs

The Green LED is a power indicator and is on when the module is connected to a powered USB port. The Red LED will flash whenever there is a valid I2C or SPI command received.

I/O pins

Each I/O pin, 1 to 4, may be individually selected to be analog input or digital Input or digital output. Inputs will not accept voltage higher than the selected supply voltage, so when operating at 3.3V the inputs are not 5V tolerant. Analog inputs span from 0v to the supply votlage, and are connectedt to a 10-bit ADC.

SCL and SDA

These pins are the I2C bus connections. They should be connected directly to the SCL and SDA pins on your I2C device. The USB-ISS module is always a bus master, and is fitted with 4.7kΩ pull-up resistors. These resistors are automatically disconnected in other modes.

SDI, SCK, SDO and CE

SDI is the SPI input to the USB-ISS, connect it to SDO on your device.
SDO is the SPI output from the USB-ISS, connect it to SDI on your device.
SCK is the SPI clock output from the USB-ISS, connect it to SCK on your device.
CE is the active low chip enable signal, connect it to CE on your device.

Tx and Rx

These are logic level signals, not RS232. Do not connect this to an RS232 port without using a suitable RS232 logic level adapter.

0v Ground

The 0v Ground pin must be connected to the 0v (Ground) on your device.

Command Interface

See the technical documentation for the command interface.