The MAXREFDES9000 is a reference design showcasing the DS28E18 that demonstrates how to both operate and power remote I2C and serial peripheral interface (SPI) sensors using only two wires. The DS28E18 is an easy-to-use bridge integrated circuit (IC) that operates as a 1-Wire® slave device to a host controller. The IC provides a 512-byte command sequencer that is loaded with commands and control data to operate an I2C or SPI device that is interfaced to the DS28E18. Once loaded, the host controller sends a 1-Wire command to autonomously execute the sequence, power, and collect data from the attached peripherals. A subsequent 1-Wire command reads collected data. Power for the attached sensors or peripherals is sourced from the 1-Wire line enabling a very efficient solution to remotely power and control complex devices such as environmental sensors, analog-to-digital converters (ADCs), digital-to-analog converters (DACs), and display controllers. The MAXREFDES9000 is designed to work as a remotely operated environmental monitoring system. This system includes a Liquid Crystal Display (LCD) screen to display the conditions of a variety of remote I2C and SPI sensors, each used to examine environmental conditions such as temperature and humidity.
Power and communication to I2C and SPI sensors via two wires
512-byte command sequencer for autonomous operation
Up to 10mA at 3.3V sensor power derived from 1-Wire
Up to 100m distance with the 1-Wire interface
Raspberry Pi® computer enables a powerful computing platform for creating an expansive system of sensors
Example source code demonstrates how to interface to various types of I2C and SPI sensors