Motor PWM control using the OpenCV library to track my hands and the tips of my pinkey to thumb (the distance). The power outputed to the motors are based off of this distance value, the greater the distance the greater the motor speed will be and vice versa. This is done through the pyfirmata2 library, in which I use python to communicate with the Arduino.
The distance d between two points (x₁, y₁) and (x₂, y₂) in a 2D plane is:
d = √((x₂ - x₁)² + (y₂ - y₁)²)
The programmed version of this is:
distance = round(
100
* math.sqrt(
((thumb_tip.x - pinky_tip.x) ** 2 + (thumb_tip.y - pinky_tip.y) ** 2)
)
)
dist_val = distance
Refer to the program code to see how everything works, its not too complicated and the code itself is quite understandable, refer to the hand landmarks to see where they are marked and positioned on the hands itself.
There are only two primary functions that are quite important:
drawFPS(); #draws the FPS to the frame of the input.
drawLineTP(); #draws the lines between the thumb and pinky all while calculating the distance between these two points.
#The rest of the code is quite simple, if video input is recived than it runs through everything and
#communicates with the Arduino.
You will need the following:
- Arduino Uno or Nano
- Jumper wires and 22 awg solid core wire
- Breadboard
- Two motors (hobbyist motors or any two motors 6V~8VDC≤150mA)
- One H-Bridge (TB6612FNG)
As for the wiring, I used one pwm and hooked up the other with it to share power and simplify the wiring. You can use any pin of choice for the IN pins. VM and VCC are connected to the same power as STBY and is needed. Once you go above these two motors (another H-Bridge), you'll have to connect an external source of power in order for the other set of motors to work.
You can watch this video to see a working demo:
https://www.youtube.com/watch?v=aQzvqGTgJ-E&t=47s&ab_channel=Ak0TecForge