WIZ550WEB-EVB controls power supply of WIZ107SR-TTL-EVB – part #1

Goal of this little work was to be able to power cycle a WIZ107SR-TTL-EVB for a few hundred times to make a long-life check of the WIZ107SR-TTL dns functionality. We therefore set up the WIZ107SR-TTL with the following properties:

The WIZ107SR-TTL (IP: is working as TCP Client, connecting to our internal server named solar – (IP:

Picture 1: Screenshot of WIZ107SR-TTL configuration

Besides this configuration, the serial debug console is activated.

The WIZ550WEB-EVB (IP: is configured with the default web server – the digital output #6 with the relay will be used to toggle the operating voltage of the WIZ107SR-TTL. In this case we do not use the default power adapter included with the WIZ107SR-TTL-EVB, but we chose to use our power supply from our lab as we can limit the total output current exactly.

This is a general overview of our setup:

Picture 2: Overview of the setup of the modules and the power supply

The WIZ107SR-TTL is powered on, when the relay #6 of the WIZ550WEB-EVB is closed. In case the relay is open, the WIZ107SR-TTL does not have any functional operating voltage. The serial console of the WIZ107SR-TTL is connected to the USB-RS232 adapter on the PC, where also the requests to toggle the relay are created. Of course the WIZ550WEB still has to be powered with the included power supply and the operating voltage of a minimum of 12V.

The output of the serial debug messages of the WIZ107SR-TTL will be logged to the PC, which also runs the scripts needed to control the WIZ550WEB-EVB. As we use free software – we use PuTTY for logging the data of the serial console (which is connected to the WIZ107SR-TTL).

PuTTY example log of WIZ07SR-TTL
Picture 3: PuTTY example log of WIZ07SR-TTL

The operating system of the connected PC is CentOS 7 – so we can use the included packages to control the WIZ550WEB-EVB without having to use the web server by clicking with the mouse.

Please read on in part #2