Spi Port; Sensor Port - Zilogic Systems ZIO User Manual

ZIO, Motherboard User Manual Rev. 2.0
3. SPI Port
Connecting 5V SPI devices. Since the SPI signal are 5V TTL/CMOS signals, 5V SPI devices can be
directly connected to the SPI port.
Connecting 3.3V SPI devices with 5V tolerance. Any 3.3V SPI device with 5V tolerance can be
directly connected to the SPI port. The device can be powered from an external 3.3V supply, or the
3.3V supply can be generated from the +5V Power using a regulator. An example circuit with the
commonly available LM1117-3.3 regulator is shown below.
4. Sensor Port
4.1. Resistive Sensors
Connecting a Potentiometer. The position of potentiometer can be sensed by connecting the
potentiometer to the sensor input as shown in the figure below. When the centre pin 2 of the
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