GPIO (40Pin Header)
The ODROID-C4 GPIO interface is similar to C2 and fully supports a 3.3Volt interface. This is beneficial for using various peripherals without complicated level shifters as with the XU4’s 1.8Volt GPIOs. Another big improvement is a faster SPI bus interface with a maximum frequency of about 100Mhz. It is significantly faster than the ODROID-C2’s 400Khz software “bit-banged” SPI.