In the post of November 11, 2013 (yes, that is quite some time ago) I announced the beta release of the application NXT to EV3 Connection Hub. This application makes it possible to use the NXT as remote control for the EV3.
When the EV3 was introduced, I assumed that it would be possible to send messages across the two bricks. It is not a strange assumption. Both bricks have bluetooth on board. So, I thought: connect the two bricks and you will be able to send messages back and forth.
For some reason (I can’t imagine a good reason for not implementing this), the Lego Company decided not to support this possibility. So I wrote a simple application in Microsoft.NET ( C#) that does the conversion of the two different protocols. Not that hard, but you will always need a PC to connect the two bricks. In the future, I might port the software to a smaller device or even better, for a smartphone.
The application connects via Bluetooth to the two bricks (the PC is therefor the master). Then, you can setup 10 channels to communicate between the two bricks. Each channel can have a different type: string, number or boolean.
So, you can connect mailbox 1 (always choose connection 0, don’t forget: the PC is the master) to 10 on the NXT brick to a mailbox. The EV3 mailboxes should be named M1 to M10, you need to enter these names yourselves. By this means, you can send commands from the NXT to the EV3. In the demo program below, the NXT brick has one touch sensor connected and one motor. If you press the NXT touch sensor, the EV3 display is colored green. And if you rotate the NXT motor, the EV3 motor rotates with the same number of degrees.
And the EV3 program:
The first mailbox is of type String and the second of type Number. The NXT is at my computer connected to port COM5 and the EV3 to port COM6, but this will be different on each computer. At a Windows computer, you will have to connect the bricks via Control Panel > Devices and Printers > Add a device. Please make sure that you have the Bluetooth turned on at the bricks. The EV3 brick should run the Home Edition firmware, for some strange reason this does not work with the Education version.
When you run the application, first connect the two bricks. And then select the two types of the mailboxes and tick the toggle boxes. The screen will look like follows:
The application is unfortunately still not available. I simply do not have the time to make it more stable, test it on different platforms and to create a setup. But if you have Visual Studio, you can have the source code. Just drop me an email and I will send you a Dropbox link.