Need help with a robot!

Here's what I got! I found an old 2003 P9000 XDT power chair. It did a diagnostics test on it and everything works great.

The goal is to control it manually using the TouchOSC program -> puredata -> arduino -> chair. I have the network rigged (the robot will tote its own router). I have the arduino happily loaded with Firmata and taking any command I desire from my laptop. The TouchOSC data will just take bit of integration and puredata programming, but I can manage that on my own.

But I'm stumped when it comes to integrating all of this tech into the wheelchair. The joystick controller has a port for charging. I've opened up the joystick and nearly cried with joy when I found a JST 5 pin connector, heading straight for the relays/motors. The five wires are (in this order) Yellow, purple, black, orange, red.

I know these five little wires control the wheel chair, but I don't know in what way. There is NO WAY I'm attaching my one and only Duemilanove to it. What if the voltages fry my arduino, just like they did to my breadboard and resistors?

The charging port I mentioned has three pins. They are all spliced. Ground(black)and power(red) and...a third orange one all connect into the JST connector. So that leaves, in my mind, the yellow and the purple to be the only two ones that control the motors

I have no voltmeter either at the moment.

So what do these two little wires do? There IS a simple on/off button the joystick, but that can be shorted easily. How can I patch my way directly into these wires?

I have no voltmeter either at the moment.

You need to fix that. Even walmart has multimeters now.

any electric or electronic project needs at the very least a multimeter.

Awesome you got a wheelchair to convert :slight_smile:
I've been working on mine for about 8 months now.
First thing I did when I got it was toss out the oem joystick and speed controller/motor driver (didn't throw away, just not using it). Not sure how yours is setup but mine needed a special programmer that you can rent or buy to change the acceleration, speed, and other settings. The current settings were extremely sluggish and slow.
I bought a sabertooth motor driver and it's been pretty awesome.
Yeah...get a multimeter and if you can on that has the continuity 'beeper' ...really helpful.
Post some pictures if you can, would like to see your progress :slight_smile:

t

Because I got griped at for not using a multimeter...I got one.

As I said, there are five wires in the JST connector. So i took a reading from each one at every state. On, Off, Forward, Backward, Left and Right. The colors are Yellow, purple, black, orange and red (in that order). Black is the common ground. Red was 26 volts...no matter what. In the "off" state, red was 26 volts. The other colors were 0v.

In ALL OTHER STATES...On, Left, Right...whatever... Yellow read as 1v. Purple as 5v. Orange as 21v. No matter what I did.

I'm even more confused now than i was.

that is quite intresting actually... urm could you include some picture?

Pic of JST

Sorry. The above is in my garden. THIS is the JST

This is the voltmeter set at the settings I used

urm could you show us how you test the pin with the multimeter in view also?
sorry if this troubles you but seriously its hard to trouble shoot anything if you dont have the actual set up infront of you.

I could just easily tell you. The common ground is connected to a port for charging. So I shove the probe in the hole for that plug. I make sure it is on the grounded side. Then, I take the other probe and touch it at the junction of each wire where the JST plugs in. There is just enough gap when it connects to put the probe in and get a reading. I touch it to each wire individually.