3pi + bluetooth


I am planning to use bluetooth communication with info updating on my netbook rather than on the small lcd onboard the 3pi. But I have no experience with communication for the 3pi, but from what I can see in the schematic the 2 lines for tx and rx are free for use and that Pololu provides a lib. for serial communication.

The info I want on my netbook is:
battery status, engine speed for left and right and updates for the onboard sensors.
More or less the same info as on the lcd in the sample projects.

My questions:
Do you have any experince from this that you would like to share?
Wich bluetooth/serial module is a good choice?

I am thinking about buying the Bluesmirf module from a local shop. Is this an easy module to start with?

Regards - Swe.

The Ezurio modules : www1.elfa.se/data1/wwwroot/webr … 300718.pdf

Are they a better choice?


The only experience I have with wireless is that a member of LVBots (the local robotics club here) added an XBee module to his 3pi. He bought two XBee modules and two carrier board kits from Adafruit. I think that the XBee modules can act as a virtual serial port to your netbook.

- Ryan

Good tip!

I have to read some more on Xbee before I decide wich one to use.
Anyone with some programming advice regarding communication with 3pi? Has anyone tried it yet in any way?


Have you looked at our example serial slave program for the 3pi? You could start by programming your 3pi with that code and using your programmer (do you have a Pololu programmer?) as a USB-to-serial adapter for communicating with it over a wire.


Aha, ok I got it, so I can use another AVR and connect for example more sensors and let the slave mcu control them and let the 3pi controle via serial commands this slave mcu. All I have to do is get an additional pcb for the 3pi and more stuff on top :slight_smile:
I am using the AVR dragon to program the 3pi and yes it works like a charm, one tip is to set some sort of support (piece of LEGO) under it, otherwise the 3pi will go off on the table like a crazy bot in circles and rip the programming cable to pieces (done that).

So I need to contact Lawicel here in Sweden and get some more Pololu stuff…

Are you no longer thinking about doing the wireless control? If you make it wireless, the 3pi should be able to communicate directly with the wireless module, without a second AVR. It also sounds like you are talking about adding more sensors, which is a separate issue.


I think I missunderstood there about the communication with your programmer…sorry.
After I read this:

I started to think about adding other sensors and so on, but not at the moment.
Now I focus on just sending information between the 3pi and my netbook.
I orderd the expansion board and a standard 433MHz radiomodule, there are many examples for the arduino on serial com. for these modules but I want to learn more standard C coding so I’ll give it a try.

I think you will have what you want if you can get the TX and RX signals connected via a wireless module to your computer. I was suggesting that you could start by connecting them directly with wires to the RX and TX lines of the programmer, which would allow you to use your computer to communicate with the 3pi without the complications of a wireless setup. Once this is working, you can make the connection wireless using your wireless module. I don’t know exactly what you got, but it probably allows you to send a serial signal in somehow and receive it on the other end. The cheapest ones are not bidirectional, so you might only be able to make one of the two connections (TX-RX or RX-TX).


Has anyone connected a Bluetooth module to the 3Pi and using the serial software (Paul provided the link for) managed to control the 3Pi’s motion?

I understand the theory of how it should work, but before I buy the gear for my 3Pi it would be good to hear that others have it working…

And of course which Bluetooth components are the best choice, so I can control my 3Pi from my PC wirelessly?

- Nathan.