::[[File:zero2w-img351.png]]

<li>Then click the '''GPIO_TEST''' button to open the GPIO test interface</li></ol>

<li>The GPIO test interface is as shown in the figure below. The two rows of '''CheckBox''' buttons on the left have a one-to-one correspondence with the 40pin pins. When the '''CheckBox''' button is checked, the corresponding GPIO pin will be set to '''OUT''' mode and the pin level is set to high level; when unchecked, the GPIO pin level will be set to low level; when the GPIO is clicked When you click the '''GPIO READALL''' button, you can get information such as wPi number, GPIO mode, pin level, etc.; when you click the'''BLINK ALL GPIO''' button, all GPIO ports will cycle through outputting high and low levels. This function can be used to test all the 40pin pins. GPIO port.</li></ol>

<li>Then click the '''GPIO READALL''' button, and the output information is as shown below:</li></ol>

</div></ol>

<li>There are a total of 28 GPIO ports available in the 40-pin development board. The following takes pin 12 - corresponding to GPIO PI01 - corresponding to wPi serial number 6 - as an example to demonstrate how to set the high and low levels of the GPIO port. First click the '''CheckBox''' button corresponding to pin 12. When the button is selected, pin 12 will be set to high level. After setting, you can use a multimeter to measure the value of the voltage of the pin. If it is '''3.3v''', it means the setting High level success.</li></ol>

<li>Then click the '''GPIO READALL''' button and you can see that the current pin 12 mode is '''OUT''' and the pin level is high level.</li></ol>

<li>Click the '''CheckBox''' button in the picture below again to uncheck it, and pin 12 will be set to low level. After setting, you can use a multimeter to measure the voltage value of the pin. If it is '''0v''', it means the low level setting is successful.</li></ol>

<li>Then click the '''GPIO READALL''' button and you can see that the current pin 12 mode is OUT and the pin level is low level.</li></ol>