is an open-source Raspberry pi car beginner's robotics project and a suitable introduction to IoT. While it is easy to replicate, the programming concepts used are of intermediate level(OOP and WebSockets)so understanding them may be difficult to beginners. On the other hand, PiCa is a fun way to get children into DIY and computers due to the easy to follow instructions made available here, while also having enough room for improvement for more adept programmers and makers (if you would like to contribute, please feel free to submit a pull request). PiCa is a 2 wheel Raspberry Pi based car, however, the Car class should be compatible with similar SoCs, such as Bannana Pi, Orange Pi, and ASUS Tinker Board.
To make a car, you need the following:
- Car chassis
- DC motors
- Wheels
- A Raspberry Pi connected to the internet
- L298N Board
If you have the parts lying around, feel free to use them, I used the following kit found here I would note that the motors are not of the best quality, but that is understandable at the price point.
After assembling the car chassis, mount the Pi and L298N on top. It is important to remember that the L298N should have a common ground from the Pi and battery pack, to do this, simply connect the Pi's GND pin(On a Raspberry pi 3 this could be pin number 39) to the battery pack GND wire (black) by twisting or soldering them together, then connect them to the L298N GND. Finally, the connections I made from the L298N to the wheels, and Pi to the L298N were as follows
,
however you can use any GPIO pins you like.
First, clone this repository to your pi. Using a terminal, type:
git clone https://github.com/Faresalghazy/PiCa
You may also download as .zip but be sure to unpack it
Second, we will assume the repo is on your home folder. In which case, open up a terminal and type the following:
cd PiCa
python3 Main.py
You should receive an output similar to :
Socket now listening at port <number>
Take note of this number as you will need it in the next step. If you would like to always use the same port feel free to change it in Main.py to one of your convenience (such as 34330). For example, in Main.py you would change line number 20 to
PORT = int(34330)
You can find a suitable port using this Android application: PortFinder
Lastly, you need to find the IP of your Pi, this can be done most easily through the terminal using the command:
hostname -I
You can expect an output of a number such as: XXX.XXX.X.XXX This is your local IP adress, take note of it. You are now ready to control your car :) .
The following instructions use two dependencies, raspivid and cvlc, make sure you have them installed using:
sudo apt-get install vlc
Be sure to also run:
sudo apt-get update
sudo apt-get upgrade
By default, video is disabled, uncomment the following line in Main.py using your favorite text editor to enable it:
#thread.start_new_thread(sendvid, ())
By default, the framerate is 24 FPS and the port the video is transmitted over is 8160, to change this, change the previous line of code (Currently line 26) to :
thread.start_new_thread(sendvid, (<new framerate>,<new port>))
For example, for an fps of 30 at port 8001: thread.start_new_thread(sendvid, (30,8001))
Finally, the default resolution is 640x480, if you would like to change it, edit the following line of code (Currently line 19):
command= "raspivid -o - -t 0 -hf -vf -w 640 -h 480 -fps "+f+"|cvlc -vvv stream:///dev/stdin --sout '#standard{access=http,mux=ts,dst=:"+v+"}' :demux=h264"
Possibly the simplest step, download the CarJoy developed by Centennial Apps from google play here. Enter the settings page, enter your IP and port (note that this works with external IPs as well), make sure to press the set buttons. Go back and enjoy steering your car. Alternatively, you can use or develop any application that sends the steering angle as a UTF string to the car
CarJoy is still under development,with the missing feature of having video built in, while this should be out soon, you can for now get a first person view of your car's camera using your favourite media player that supports online streams, make sure to reduce the buffer to as least at possible (in ideal world, you would set the buffer to zero, but try starting 300ms and experimenting to your convenience). Using Linux, to start vlc and watch the video. launch the terminal and type in the following command:
vlc tcp/h264://<yourip>:<yourport>
By default, would be 8000
- Currently, the Car.steer() method does not work with all angles, but rather a small range, a future update could make the car move at exact angles rather than rotate right or left, and move forward and backward.
- I am currently working on receiving video from the car using CarJoy and a videoview, this should be finished soon.
- Don't let PiCa be my project, let it be our project. I would be happy to see everyone contributing to it, as a result, if you are able to improve the Car class or any other parts of the project, or add new features, please do so and submit a pull request, you will ofcourse be credited