Project Description

In this posting, we are introducing an example code to control the LED & read the value of variable resistor of WizFi250-EVB. Without additional MCU board, a smart phone App directly connects to WizFi250-EVB and controls GPIOs.



From the WizFi250 firmware version, the commands for GPIO and ADC has been supported. You can download the latest version from below link.


You can control GPIO1 in the WizFi250-EVB with below commands.



Below commands will let you read the ADC of WizFi250. WizFi250 supports 12bit ADC that is controlled by GPIO 5 in Wizfi250-EVB. You can see the ADC value changes from 0 to 4095.


Testing GPIO of WizFi250-EVB

Let’s control the GPIOs of WizFi250-EVB. For the testing, we will connect the LED & variable resistor to WizFi250-EVB as below figure.



We need to change the WizFi250 operation mode to air command mode. You can use below two methods. Both of them are examples about Air Command mode with TCP 50001

<Air Command mode using AT commands>

When WizFi250 operates as station mode and associates with an AP, you can change it to Air command mode using AT commands (for more detail, refer to


Air Command mode using a function button in WizFi250-EVB (When WizFi250 operates as AP mode)


Now, a smart phone app will connects to WizFi250 using air commands.

Execute the WizFi250 smart phone app and select the configuration menu. Input IP address and port number of WizFi250 and press the “Connect”

If you touch the LED button in the app, you can see the LED on/off. ADC button gets & displays the ADC value of WizFi250. Status button will show the WizFi250 status information.



You can download the smart phone App source code from below link.

WizFi250 Smart-Phone App Code Download