Let's Make Robots!

CtC's Aurdino Journey

So I am in the Arduino water and have started to swim. I found a cheap off-brand Wii Nunchuk controller, made a PCB adapter for the plug and have it playing nice with my Duemilanove. I have also taken all the numbers coming from the nunchuk and converted them all to nice clean 0-255 ints. From there, I coded a serial receive loop so the whole unit could be used as a stand-alone plug-in to other devices. Basically, the chip just sits there and waits for a single character followed by a CR. I.e. if you send a "J",CR this "turns on" the joystick and the Arduino starts spitting out (via serial) the X and Y of the joystick. Send "J", CR again and it stops sending. Same with "A" for data from the accelerometer, and "B" for buttons. "O" is off --all of them off. You can turn one or all of the nunchuk's sensors on at any one time.

My intention going into this is for Walter's virtual control panel. I had a "virtual joystick" on-screen which was not very convient. It was very tough to watch your cursor on the screen whilst also watching the robot on the ground. Obviously, this lead to wanting a small, one-hand external joystick, attached to the computer, and feeding data to the control panel (Processing) --to be relayed out to Walter. This little nunchuck is not only the right size, shape and configuation but the tilt-sensors and couple buttons are just a plus to be added to future projects.

Now here's the question:

What is the smallest off-the-shelf Arduino board and what is the smallest Arduino-friendly FTDI board? I would assume the former would be the RBBB --I am in the market for a link to the cheapest ones people have found. And I would also assume the smallest FTDI is the cord that looks like a standard USB cable but has a 6-pin female header strip on the other. Are these thoughts correct? I welcome any input here. The end goal is to get the arduino and ftdi inside the nunchuk remote with just a standard USB cable coming out the tail. --Now tell me that would not be awesome? --A stand-alone USB nunchuck remote plugged into your lappy--what could be cooler than that?

Thanks for everyone's help on everything so far.

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i found out that the solarbotics ardweeny is even smaller, with embedded ftdi pins. you could use jumpers or extenders, and have the 6 pins sticking out the back of the nunchuck.

bonus idea: use the accelerometer to control walter's head. the c or z buttons could work as a trigger

You could use Picaxe USB cable if you just put 3,5mm stereo jack on your Nunchuk. This way you don't have to put FTDI chip inside. But of course you have to invert RX and TX signals either with hardware or FT_PROG. I haven't had enough guts to try to change the config on my only Picaxe cable so I used HW solution. This just came to me because I wrote about using Picaxe USB cable in this thread.

Of course this means cable sharing and if you use your Walter-joystick and want to program Picaxes you have to switch cables all the time. In that case FTDI inside the Nunchuk might be more convenient.


The Arduino Pro Mini is a damn small board with FTDI connector.

Thanks guys,

I checked the arduweenie which looks great, but no places to solder wires. I would have to solder directly to the pins, add a socket and solder to that or add a pcb. I do like the idea of a pic-backpack though. I am leaning to the mini from sparkfun (how did I not see this one before?) and the RBBB. At this point, it really just comes down to actual dimentions and what will physically fit inside of the wii case. The cavity inside, as I see it now seems to be longer than it is wide so the RBBB with the "power end" cut off seems to be the way to go. I think the bottom line here is that I just need to replicate these boards in cardboard and simply place them into the nunchuk to see what fits better.

Now, on to the fun stuff:

This single $8 remote has sparked my brain a bit... I think for fun, I might make a video game in processing. The obvious choice here would be to make one of those wooden games with the maze, marble and X/Y tilt controls. This should be easy enough to code. I have already coded a nifty little dot that rolls around the screen as I tilt back and forth, now I just need to figure out how processing will know that this ball is in contact with one of the lines that comprises the maze. I also have been drooling over one of these tiny little OLED screens as well --This screen is a way's off, in terms of fiscal priority it is very, very low on the list but man, how cool would it be to have a tiny, full-color, video-ready 1" screen attached to my new controller? Ah, more dreams than money. Not to mention, I really should focus on what I have already and the coolness of code... Really, if I were to never buy another part, I would still have an unlimited number of build possibilities by just modifying my code and making the stuff I already have do different things. I dunno.

Good things to come.

I think you'd have the best luck with using the Arduino mini. I think they come in 3.3 and 5v versions so depending on your needs, you just need to chose the right one. I only say the mini because of the height factor as it's all smt vs the rbbb which uses the pdip and adds severall mm of height which may not work for the controller. It may cost a bit more, but you'll have to weigh that in as a factor of it's compactness vs the cheaper larger rbbb. The other option to make the rbbb more compact is to trim the board a bit as they illustrate here as well as leave the socket to mount the 168 off and directly mount the atmel168 on the board. From looking at my rbbb, you'll also need to angle the programming pins down if you want to reprog as well as use a small crystal(resonator might be a better option). You may also need to use something other than the barrel type caps as they may add height even with low profile types....maybe tantalums?

Screw the USB, put Bluetooth in there!!   ;^)

Quick update on the progress.... Yup, I can stuff a lot of stuff in there it seems. So far, I have (in this one, tiny nunchuck case) a FTDI chip and breakout board, USB cable (with the plug still on), Picaxe 08m, RF TX module, a RGB LED, and a cardboard stand-in for the Arduino mini. I have also fabricated a nifty external antenna mount for the RF TX.  I know what you are asking... "Why the picaxe and RF?" Well, I must say that the Arduino does a lot of things well, however it doesn't talk to a $5 RF TX unit very nicely. Not at all well, actually. I want to be able to have a battery powered remote for Walter, one that does not require the laptop to be on or a Processing App to be running. For power I will have to use a 5v USB plug (aka "iPod Charger" or "Cell phone booster") for power. Eventually, and according to cardboard stand-ins, I should actually be able to stuff a small lipo and lipo charger inside as well and be completly wireless. My absolute dream would be to fabricate a small bracket to hold one of these OLED Displays


Yeah, I saw the libraries for Arduino and the "$5 Tx" units. I think that frits stumbled upon this method of using these transmitter units in his picaxe post here. I think the arduino library and his "warm-up" routine are probably doing close to the same thing. However, the arduino library assumes that there is going to be an Arduino on each end of the transmission. To be honest, this was a "if it ain't broke, don't fix it" issue. I have used this particular unit and code for ever now --it is solid, works everytime and I do not loose data --I'm keeping this set-up the same... with a picaxe. Not to mention, the picaxe has a handy IR out function that talks to my TV quite nicely. I had an extra pin left on the 08M I am using so I went ahead and added a TV remote function as well. --Why not? I could drive walter around AND change the channel --what could be better?

Now, in terms of the OLED displays --I just can't seem to get over these things... They are < 100 bucks ($65 for the 1.5") full color, graphics, text, they will display images and will even display video from thier on-board microSD card. All this in a nifty little screen with just a serial UART to talk with? --Brilliant. I would just love to fabricate a small bracket to attach one of these to this remote.

Here it is in a nutshell: This is my inspiration and what started my lust for these screens