Easy build self balancing electric skateboard

Step 30 Hand controller wiring

My "de-luxe" self balancing skateboard has a wireless Wii Nunchuck as the control system.

However here we are interested in reducing cost.

Therefore we have a cable with a hand controller on the end.

This has a dead-man switch (cuts motors if you let go i.e. fall off)
Also has steering left and steering right plus a switch to fine-tune the balance point of the platform.

Here is wiring diagram:

"D" is the 1500 Ohm resistor.

Comments

[aniles jr]

how can i use a potentiometer to adjust the how tight the turns are and i want to do this on the handcontroller?

[XenonJohn]

I would get it to just balance first. Concentrate completely on that.

Eveything else after that can just be classed as refinements.

Sure, you could adjust the target rate of turn in degrees with a potentiometer, you could also make it inversely proportional to the estimated speed which would be a good thing.
For example I am currently working on using 2 pressure sensitive resistors under my left heel and toe to allow it to be steered by leaning, and stopped by rolling foot sideways so not pressing either resistor. This also means you can lose the deadman switch. Lots of things you could do - after you've got it to balance!

John

[aniles jr]

wen i get mine to blance can u help me out to do that so we i lean it will turn?

[aniles jr]

were do i get the 5volts from

[XenonJohn]

The terminal on the arduino labelled 5V

(the one labelled 3.3V next to it powers the IMU)

John

[aniles jr]

how can i use a potentiometer to adjust the how tight the turns are and i want to do this on the handcontroller

[kevman0044]

What would I have to change in the arduino code if I wanted to use a potentiometer for variable turn rate?

[XenonJohn]

There is an image on front page now of a version with a wii nunchuck attached. All I have done is solder wires to the two 10K potentiometers in the chuck thumb joystick, and to the buttons on the end to use them as my "deadman" switch.

Good thing about this is that the pots self-centre at about 5K resistance point. So with some experimentation you can connect them to an analog input each for steering left right and to fine tune the balance point using the forward back motion.

Two main values in code affect steering:
Steercorrect is a variable that is generated by second "headlock" gyro to make it resist slight turning forces, for instance if one motor has more friction than the other, to keep it in a straight line.

The other variable is "Steer". A value of zero is no steering i.e. keep going straight ahead, a -ve value is left and a +ve value is right. Do some experiments with hard codinjg in values for this but you need your potentiometer to vary the value of "Steer" remembering to code the data from your pot so that a Steer value of 0 is straight ahead.

Hope this helps

John

[technoguy94]

I know you're trying to keep it cheap, but could you at least have the wiring diagram+program for the nunchuck? I don't know about anyone else, but I would prefer it if/when I build one.

[XenonJohn]

Here is an instructable on a general purpose arduino / standard Wii Nunchuck interface I have just done. There is plenty on the net on this but this should be a reasonable way to get something working.

www.instructables.com/id/Wii-Nunchuck-as-general-purpose-controller-via-Ard/

[XenonJohn]

Having enough trouble keeping up with all those attempting to self-balance!

I think best thing would be for me to make a separate instructable on how to steer something with a wired and a wireless nunchuck and then put a link to it here.

My wireless nunchuck board uses an arduino just to continuously read data from the wireless nunchuck. It then varies voltages on the output pins which are sent to the steering inputs of a separate (older, non-arduino) board that is controlling the balancing and power to the wheels.