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Velleman K8000 - [K8000 Standalone Usage] - [K8000 Wireless Server]

K8000 Server

Introduction to the K8000 server

Sometimes people are asking me if it is possible to control the K8000 over a wireless connection. Sure this is possible. In fact there are several possibilities to do this.

The K8000 card is using the I2C protocol to receive commands from a master. The I2C protocol is a 2-wire protocol that was originally designed to communicate between chips on an electronic circuit. You could create a wireless communication by making a transmitter to send/receive I2C commands. But it would be hard to implement and I2C was not designed for such purposes anyway.

Instead it is better to add a controller to the K8000: This controller will handle all the I2C communications with the K8000. The controller will also handle the wireless communications. This wireless communication doesn't have to use the I2C protocol: the controller will act as a translater between I2C and any other protocol.

diagram of the wireless controller

The easy solution: FEZ Panda II and (Wi-Fi) Ethernet

This kind of project can be made with a regular microcontroller, like a PIC. But I have chosen to use the FEZ Panda II board as the controller. The reasons are obvious: I already have a lot of experience with the combination Fez Panda II / K8000 card and the FEZ is very flexible.

The Fez Panda II doesn't have a wireless module but it has something even better: a wired Ethernet connection. It can be easily turned into a wireless device (Wi-Fi) by plugging this ethernet connection into a wireless brige (Wi-Fi to Ethernet).

There are many advantages in doing so. First of all Wi-Fi is reliable and it provides encrypted communications (by using a WEP or WPA key).

The following image gives you an idea of the complete system I worked out. At the left you see a computer that is connected to a wireless Wi-Fi network. Then there is the FEZ which is connected to a wireless access point (ethernet-to-wifi bridge). The FEZ is also connected to the K8000.

setup for the wireless transmission

Building a wireless application: the requirements

So we just decided to proceed on with the K8000 / Fez Panda II / WiFI solution. You might wonder: what do I need to make? It all depends on the type of solution you want to make. I have chosen to write a TCP/IP server that runs on the FEZ Panda II. This server will accept incoming TCP/IP connections from a remote client. We need to to the following things before we can make it work:

All this might sound complicated but we need to split the project into pieces. Then we need to work out piece by piece: we have a client part, a server part, and a protocol for the communications between them.

diagram of the client/server model

Project contents: the pieces

Here you can find the different pages for all parts of the project:

Copyright ©1998-2022 Vanderhaegen Bart - last modified: August 24, 2013