Terminal device and system for detecting connection of external device

A terminal device, comprising:

• a power supply module, a first element, a pogo pin connector, and a processor, wherein the first element is an element having a resistance value less than a specific value;
• the power supply module comprises a positive connection terminal and a negative connection terminal, the pogo pin connector comprises a positive pin, a negative pin, and a communication pin, and the communication pin is used for communication between the terminal device and an external device;
• the first element is connected to a path between the positive connection terminal and the positive pin, or the first element is connected to a path between the negative connection terminal and the negative pin;
• the processor is configured to determine that an external device is connected to the terminal device when a voltage difference exists between two terminals of the first element;
• and
• the processor is further configured to control a voltage outputted by the power supply module to increase from a first voltage value to a second voltage value when the voltage difference exists between the two terminals of the first element.