These two could be read with an Arduino, but you'd have to first figure out what SPI or I2C protocol is being used (clock rate and a few other things) and for that you'll need an oscilloscope or digital signal analyzer. That is, the conversion from analog to a basic digital signal takes place inside the joystick. There are some controllers, however, (if I recall correctly the Dynamic Shark is one) that use a joystick with digital output (again, memory only here, SPI, but might be I2C). I have both inductive (which yours is) and Hall effect analog sticks and they can be hacked in the same way. Hall effect, but whether it is an analog-output or digital-output joystick. I'm presenting to the local robotic club on this tomorrow night so there will be a fire under my butt to move on the blog.ĭoug DougL Posts: 69 Joined:, 22:47 Location: San Diego, CA USA I've not yet setup a blog on this but plan to do so soon.
The controller firmware handles the _tank_ steering. I just have to give it commands to move a percentage(0-100) forward, backwards, left and/or right or a combination. What I like about this solution is it leverages the forward/reverse _and_ turning configuration built into the firmware on the GC2 controller. Jack, I too went down this road and was not satisfied with getting into the physical joystick signaling so I built a logic analyzer from an FPGA board(Papilio - ) and figured out the protocol for the GC2 controller.
Is it possible to keep the existing wheelchair circuit boards and somehow use an Arduino to control the wheelchair? Or would it be easier to just scrap all the control boards and start from scratch, keeping just the motors and batteries of the chair? I know these chairs have a ton of safety features which makes it difficult to do projects like this. I'm not sure the brand of chair but it uses a Shark power module and control system. I found a little information on this site but couldn't find any information on actually setting this up and getting it working. I am looking to interface an Arduino board into an electric wheelchair.
You just need to program it with the software that's available free if you ask.īurgerman Site Admin Posts: 58869 Joined:, 21:24 Location: United Kingdom It also has current limiting and 101 other things you can set up and will require. And includes such essentials as motor compensation so you get almost max torque at low input signals without requiring feedback from the motors etc, and will give controlled turns and speed independently. It also has proper control logic rather than simple tank steer which wont actually work for you, although you haven't found out why yet, and can be reprogrammed and configured. The joystick is analog? So it would be relatively easy to program an Arduino to mimic the joystick signals and control the motors that way? Has anyone done this before? I'm assuming some of ya'll have used this controller in the past. Okay, that listing doesn't really have much information, the controller looks pretty old, how can I be sure it will work for what I want to do? How do I know it's the right specs for my motors? oller.html jcka22 Posts: 15 Joined:, 21:00 It has over-current and thermal protection, are over-current protection and current limiting two different things?Īlso, the previous PWM frequency was 20kHz, will there be any problem using something with a higher or lower frequency, like 16-24 kHz? Something as small as 40A continuous would probably work, as long is it had a high max rating (~100A) right? Obviously this is a little pricey for me but if I could find something similar for a little less I could probably swing it. What do you all think? 60A continuos and 120A max should be sufficient. And if I am going to get one, I'm probably going to need something more like this. It seems like what I need is a good motor controller.
Buying a different wheelchair control system and hacking the joystick doesn't seem like the most efficient way of doing this. I looked at some P&G controllers on eBay but they were around $100 and that wasn't with the joystick controls. Okay I think I'm getting a better idea of what's necessary now.