Acrosser AR-ES6003FL - Manual (Page 63)

6.2 Digital Inputs
There are 4 clamped diode protection digital inputs on GPIO_COM1 connector.
You can read the status of any input through the software API. These digital
inputs are general purpose input. You can define their purpose for any digital
input function. The detailed information please refers to Software
Programming Guide for how to use the API.
Following diagrams state how to connect the digital inputs to devices on the
embedded system.
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