Thanks for the video. how can i access to the serial port in both IDE, python IDE and arduino IDE? because when i open the serial monitor on arduino IDE, i can't open it on pycharm ?
When running the python script the serial monitor cannot be open along with the script trying to sends commands to the Arduino. To fix this you must only have one open at a time. In your case I think making sure to have the serial monitor closed before running the program will fix it
Fix the axle on both sides. Modify the pen servo holder to a linear actuator that can lower or lift the pen from the paper. Make sure the belts are as parallel with each other as possible
Keep at it. Even a wooden dowel would work well as a shaft, . Even better if you had a top/bottom roller that were mated with gears to provide opposing drive function, but that would add to the mechanical complexity. At the minimum constrain the opposite side, and for added results, constrain the back of what the paper slides on to the shaft with some springs or something to make sure you get good traction. Your pin could also stand to be transposed a little bit off axis so that the rotation results in more upward movement of the tip, and less horizontal movement of the tip. That would require the servo actively apply torque to push the tip into the paper. Conversely, just print a little channel, and put a rubber tire or whatever on the servo so it acts like a rack and pinion. Put the pen into the vertical channel, which constrains it into just moving up and down, and then the servo can push down on it as needed, though that will likely result in some slippage. This could be fixed with gear teeth or with a linkage.
I made one of these for one of my engineering classes and I would love to send you the files if you want. I used paracord as a drive belt in my design. I love the way you move the pen off the paper with another servo motor. That's a functionality that my design did not have.
Making the belts parallel with your axis instead of on an angle will increase your accuracy a lot. You could also put the pen in a tube to travel vertically up and down and have the servo arm drive a pin on the side of the pen up and down.
This works by first having the laptop take an image and generate that into gcode instruction that can then tell the motors to move to specific cordinates on the paper and then when to move the pen up and down. The calculations are done in the universal gcode sender application, and then these instruction are sent to the arduino microcontroller where it then controls the motors with the instructions resulting in movement. This was a fun project to work on the most engineering was definitely in the 3d printed parts and deciding on materials to use!
For those confused as to what a pen plotter is and what it can do, when hooked up to a computer it can draw out whatever file you ask it to draw, so if it's a bunch of text, it will write that. Same with drawings. However, the most useful feature that isn't making it a knock off DIY printer, is setting it up to follow the contour of a physical object. Doing that will give you a precise template of that object, allowing you to make an exact copy the first time. This is especially great for restoring things that aren't in production anymore
Hey brotha, just commented on the short but this provided good insight for me to get some ideas. The coat hanger should work as long as you fix it on the right. Still not sure on the necessity of the servo unless you definitely want a dotter, in which case it would work better with the pen on a 1 inch horizontal lever, then drive the servo way less. This will simultaneously allow the pen to overpower the servo a few mm with the torque from being offset (should increase your success rate of pen contact) as well as allowing you to more accurately affix it to the system since the pen itself will rotate much less. Im by no means a pro but I finished mechatronics with a 100 if you have any specific questions 😎😂
Excellent! The idea of moving the pen is much better than what I am doing and I think it can be done compactly, Ill let you know if I have questions. Thank you for the advice!
Sub the paracord for a large O-ring or plastic tread and gear wheels instead of pulleys. Also theres nothing keeping the paper held to draw it from what I can see, duplicate the paper driving system underneath and run the sheet between 2 lego tires like a two-high rolling mill. Should draw the paper through. Once you have that you can fix your base way easier and just feed it. Also not quite sure of the use of the servo in this application other than removing the pen from the page when youre done
The servo is supposed to pick up the pen when drawing so that it can create drawings that have white space between the lines. I plan to use belts in the next version. Good eye on the lego wheels haha I found they work pretty well. I had to look up a rolling mill and that seems like a great approach im going to try out!
It's just a DIY printer for CNC enthusiasts. You can use it to turn PDF files into printed texts of course, but you can also use it to draw for you or set it up to follow the contour of another piece, allowing you to make a precise template of that piece, which is arguably the most useful feature of a pen plotter imo
I’m currently pursuing my computer science degree and have learned CAD and electronics in my free time but to do this as a major I would recommend mechatronics robotics or electrical engineering
File "c:\Users\sibme\OneDrive\Desktop\Face-Tracking-Turret-main\Face-Tracking-Turret-main\Webcam_Python\face_Detection.py", line 1, in <module> import serial ModuleNotFoundError: No module named 'serial' how can i overcome this issue? please help,sir
Can anybody shed some light on a persistent problem I encounter? With code attached to this video and all of the similar face tracking videos, as soon as the python detects a face, the servo motors instantly move away from the target. I know how servo motors work and I can see how the code is supposed to work, however, every Arduino code gives the same result, the servo motors rapidly move away from the identified face.
Could it be that the servo's are wired backwards, like ground goes to positive and positive goes to ground, in that case switching the wiring might switch the direction of the way to motor turns but im not sure. A way to fix this in the code would be reflecting the image before doing the image processing of finding the face
@@owenobrien8804 Thanks, but I have tried both of these. Added code in python to invert the image. Checked the wiring and reversed it. No difference. I know it’s something in my setup, but I can’t see where. Even connected a picoscope and could see the PWM signal changing as the serial buffer was filled, but the servos still flip out and go to odd and arbitrary position.
The first parameter is string of the file path of the usb device in my case it was /dev/cu.usbserial-110, and then the 9600 is the baud width, this is declared in the arduino code as 9600 and shouldn't have to be changed. To find the first parameter on your own computer when you select ports in the arduino IDE it should say which one you are connected to and by copying that path it should work.
0:58 - U can C how it's jerking, and that's because of the servos - they've got min 1 degree steps and nothing you can do. maybe only bldc gimbal motors or steppers with microstepping can do it smoother. I'm bashing my head on similar to get my gopro to rotate left/right with the steering wheel of a car, and with servos, even for 50 euros, the image is terrible, jerking like here
Steppers would be a great improvement because of there greater precision and accuracy! I plan to work with the Nema 17 stepper motors soon and it would be cool to try and implement those into this design. Good luck with your project, post a video of it when it's done I like to check it out!
Like he said steppers are probably better, but I'd just gear the servos down (or use a linkage) and call it a day. Depends on the use case ofc but I think you'd only need 2/3x to 1/2x the range of motion. Just a thought.
Do you have the code for this project? I am doing a similar project, but I will need to modify it for stepper motors instead of servos. Also, is your computer webcam supplying visual data to the device or is it something else?
I have the video from the webcam on my computer processed through Python and then the location for the servos is communicated to the servos over serial communication. The built in computer camera can be switched to a external USB camera by using a different port in the code. Heres a link to the github for a closer look. github.com/OwenTheGreenBean/Face-Tracking-Turret
You should upload all of those code and 3D model files somewhere for download, this is super cool stuff! I’m looking into doing something similar to this for my senior project at my engineering program, I want to make a self driving turret to attack my classmates 😂
Thanks so much dude! I just now hooked up two of my little DC fan motors to 3D printed rollers, and have a working shooter mechanism to mount onto this awesome contraption! I’ll keep you updated and put some credit to you on the final piece.
