Pi/Arduino Robo-Car

[Brad]

My current electronics project is to take a toy RC car and turn it into a web-controlled Robo-car using a Raspberry Pi and an Arduino.

Luckily for me other people have already accomplished this task so I won't exactly be blazing any trails with this project. Seems like a good stepping stone towards more advanced robotic vehicles.

I'll be using the Raspberry Pi as a Node.js server which handles all the user interface and communication. The Arduino will be connected directly to the steering servo and the DC motor. There is a handy module already created for Node.js called Johnny-Five which enables communication between the Pi and the Arduino out of the box. For a psuedo-real-time experience I'll be using socket.io for communication between the client and server.

The Pi will also be equipped with an RPi Camera for video/photo taking.

I've chosen to use a toy car so that I don't have to worry about building a chassis, getting steering working, etc... It cost like $12 at Wal-Mart anyway.

So far I've stripped the RC car down to it's body and base electronic components. Most of these components I'm going to strip out too. Photos are attached.

Next step is starting on the base Node.js server, creating a server which can take and display photos from the RPi camera. Also, I need to practice wiring up the Arduino to a servo.

PS. I would have made this a blog post but attaching photos there is too much work (no upload option) so I didn't.

[Nick]

To the new blog, or old?

Awesome project! I attempted something similar once (I was using a wifi-router, as there was no PI yet) and ended up frying the RC cars control board trying to find the inputs that control motor speed. I did get steering located before I broke it

Are you going to piggy-back the RC cars control board, or implement your own? You could get a cheap brushed-motor speed controller (ESC) to control the forward/reverse. How you do steering depends on if they used a real servo or not. You unfortunately can't pull a lot of power out of a Raspi/arduino. But there are schematics all over for h-bridges and the like for that.

Is this going to be phase one of the Sub-PI project?

[Brad]

From what I've seen other people do I shouldn't need to use any part of the rc cars control board. Some additional electronic components will of course be required to get power to the servo and DC motor. But i think i will build my own rather than using the cars board. If my understanding is correct I should be able to run the whole thing off a single rechargeable 5v battery.

This is the first step towards a more advanced method of transportation, yes. I am trying to start as simple as possible. Also the car won't sink to the bottom of a lake on its first test run.

[Nick]

Also the car won't sink to the bottom of a lake on its first test run

[Brad]

My Node.js server is up and running on my Pi. The server includes a button which when pressed causes the Pi to take a photo using the Pi Camera.

Still having some issues with serving that image back to the client. The communication is working fine, I just haven't been able to deliver a valid URL pointing to the image.

I think this will require me to use the Express framework to do well and without a ton of work. I was considering using that anyway. Just one more Javascript framework to learn.