Title of Invention: IoT Maneuvered Intelligent Cartesian Plotter System on Android Platform
1. BACKGROUND OF THE INVENTION:
In the day-to-day, we always have some tasks which have to be done with hands like writing or signing. These things are always done with hands. As we are involving computers to everyday use we are also planning to involve them to even in writing and drawing. Project 2D plotter is simple and modern pen plotter. With help of this, we can write, draw and do many things that we can do with pen and paper and help to reduce the all human efforts.
The present invention is said to numerical control (NC) and more significantly to computer numerical control (CNC). Numerical control is that the generic term applied to the automation of general purpose machine tools. Such automation is achieved through electronics and, utilizing computers.
Movement is controlled along different axes, normally no less than two (X and Y), and a device axle that moves in the Z (profundity). The situation of the apparatus is driven by coordinate drive stepper engine or servo engines keeping in mind the end goal to give exceedingly exact developments, or in more established plans, engines through a progression of advance down riggings. Open-circle control fills in as long as the powers are kept sufficiently little and rates are not very awesome. On business metalworking machines, shut circle controls are standard and required with a specific end goal to give the precision, speed, and repeatability requested. This situating and control data (the NC information) makes up an NC program or part program which is made by a tooling engineer.
Traditional Computer Numerical Control (CNC) demands the complete engagement of Computer with it. Movement of axis is maneuvered with the help of stepper motors with are controlled with the help of gcodes. Gcode is scripting language which controls the steps of stepper motors resulting in movement of machine tool. In older days gcode has to be written manually by tooling engineer. Nowadays gcode is normally generated with the sophisticated software. This software is also to be used by trained professional.
2. DETAILED DESCRIPTION OF INVENTION:
2D plotter is basically a Cartesian robot which moves in two axes. At the end of the arm there will be a pen which will draw according to given commands. The commands given to the plotter will be in form of co-ordinates which will be provided by remote platform which can be mobile or personal computer of user. Encoding image in form of co-ordinates will be done in remote platform. Remote platform will be able to decode images as well as drawings. 2D plotter is a to a great degree flexible machine, intended to serve a wide assortment of regular and specific illustration and composing needs. You can utilize it for any errand that may regularly be

completed with a handheld pen. Fig 1 demonstrates the entire piece outline of proposed innovation.
It enables you to utilize your smartphone to create composing that seems, by all accounts, to be handcrafted, finished with the unmistakable appearance of utilizing a genuine pen (rather than an inkjet or laser printer) to address an envelope or sign your name. Furthermore, it does as such with accuracy moving toward that of a gifted craftsman, and — similarly as essentially — utilizing an arm that never gets worn out.
The pen holder fits a wide assortment of pens, including Sharpie fine and ultra-fine point markers, most rollerball and wellspring pens, little bodied whiteboard markers, et cetera. It can even hold a wellspring pen at a legitimate point of 45° to the paper. You can likewise utilize actualizes other than pens, for example, pencils, chalk, charcoal, brushes, and numerous others.
Primary challenge in this project was to generate gcode from image automatically without human interaction. Software tools available needs human to generate gcode. So invention rectifies the human interaction by converting it to Scalable Vector Graphic (SVG). Then encoding it to gcode.
SOFTWARE DESIGN:
Fig 2. shows the flow chart of proposed idea. The flow of process begins with the acquisition of the image from a user. The image is imported via an Android app designed for further processing. Since the scope of the plotter is limited to lengths of X-Y arms so we have to re-size image according to that. After resizing the image is converted to a grayscale image. Grayscale image edge detected or thresholded according to the image. This will be selected by the user. Edge detection depth is variable so we can customize the image properly. This will help us to get proper idea about output gcode generated. Thresholding value to be used while thresholding is also variable. We can adjust the span for the for adaptive thresholding too.
The processed image is transferred to the Arm computer to generate Gcode. Generation of Gcode consists of tracing the bitmap and points traced are represented in form of Gcode in filename .gcode file. The gcode file is a script of control co-ordinates of CNC machine. The gcode is sent to the Arm computer line by line which is handled by python script running on Arm computer. The gcode is sent serially to the Arm computer by using the PySerial python serial communication library.
Android Application
For proposed project Android application is going to be used which simplifies the work of enhancing image to plot. Application is designed to perform edge detection and bringing the image to threshold individually as well as at same time. Application uses Canny edge detection to detect edge of image.

For threshold image, the application uses global, adaptive mean and adaptive Gaussian threshold as per requirement which is decided by user. When global state is selected the application enables user access for threshold adjustment. When adaptive mean or Gaussian selected the application enables user access for block size adjustment.
The proposed apparatus requires image in discrete form for plotting purpose. This discrete form of image is rendered through custom developed Android application. The application provides the apparatus with this discrete information of the image through firebase cloud database.
WORKING OF ANDROID APPLICATION
A. Image Acquisition
The image can be retrieved from internal storage of Android device through "SELECT IMAGE FILE" button. The user interface is designed to be user as simple as possible. User can adjust the image resolution as per requirement. Refer Fig. 3.
B. Image processing
The application converts RGB image into grayscale format so that the threshold and edge can be detected. User can adjust minimum and maximum threshold value for Canny edge detection (Refer Fig 4.) and block size for adaptive mean threshold (Refer Fig 5.). The user can select adaptive Gaussian and adjust block size accordingly. He/She can also select edge, threshold or both as per requirement. Finally, edge format and threshold format of the same image is combined using bitwise AND operator and discrete format of image is obtained. Refer Fig 6. After requisite changes user can upload the image on database through upload button on top-left or can save image in internal storage using tick button on top-right.
C. Gcode Generation :
Generation of the gcode is one of the most important part of proposed project. Image is fetched to the Arm computer and converted to Scalable Vector Graphic(SVG) with the help of open source python application. Scalable Vector Graphics (SVG) is a XML-based vector picture organize for two-dimensional designs with help for interactivity. Refer Fig 7.
In this image format image in defined in form of vectors instead of pixels. Each line or edge in image is defined in separate path tag. In path tag there is a attribute 'd' which contains the actual path data. Path data starts from character 'M' which indicates 'Move to' and ends with 'Z' which ends the path. Similarly, some more characters are there in SVG which contribute in creation of path like 'L' which means 'Line to' , 'H' means 'Horizontal line to', 'V means 'Vertical line to', 'C means 'Curve to', 'S' means 'Smooth curve to', 'Q' means 'Quadratic Bezier curve', 'T' means 'smooth quadratic Bezier curve' and 'A' means 'Elliptical Arc'.

After encoding image in vectors, a python script is used to hatch or shade the image. This step is makes it easy to shade the image when it comes to actual drawing. In this hatching angle and space is defined in program. For hatching in closed path from one point, it checks for any co-linear point on same close path and connect those two points. Then it shifts to next point and process repeats. Refer Fig 8.
After hatching gcode can be generated but, hardware has limited work area and svg can be exceed in size. So we resize in this step. Resizing of svg is done by open source software.
After resizing next step is to generate gcode from svg path. To generate gcode each svg path is processed. Each path is first converted to array of coordinates. These coordinates are encoded to gcode commands and added pen down and up commands at beginning and ending respectively. The plane to work and speed of pen is also defined in gcode. And at the end is goes automatically to the home position.
HARDWARE DESIGN
The system architecture consist of the basic blocks Android application input, Arm computer,Embedded System, CNC shield v3, Power supply, and X Y axis motor with one servo motor for pen movement. Android application giving input to the arm computer which and what to be written or draw which forms an IOT platform. According to data that data is given in series to the Embedded System. This data is the basically gcode which controls the motor movement. Gcode consist of the vector points of the destination data which controls the motor movement and the input data from android app is converted into gcode by the Arm computer. An Embedded System board then receives the gcode which the actual control signals for motors but as arm computer cant drive the stepper motor we attach CNC shield which have drivers DRV8825 which drives the motors. The two stepper motors for X and Y axis and one servo motor for pen movement draws the actual data on paper
ARM COMPUTER
The arm computer getting the input from the android application and the this data is converted to the gcodes which contain vectors of the input data. So this gcode consist of the all valid information about the motor movements.
EMBEDDED SYSTEM
The embedded system is programmed for each input given from arm computer. Instead of using the computer for programming the embedded system the arm computer program the embedded system as per the gcodes of input data. By this information embedded feed the input data to the motors.
STEPPER MOTORS
For our application we are using the 3 stepper motors in our system. The two motors used are stepper motors which have high torque of 5.2kg/cm running on 12v 5amp supply. The 1st motor

is used for the x axis and the 2nd motor is used for the y axis movement. And the 3r stepper motor is used for pen movement for pen up and down. For this application we are using the 28byj-48 stepper motor having torque of 1.4kg/cm. The motors are rotating according to the vectors given in the Gcodes.
CNC SHEILD
CNC Shield can be utilized as drive extension board for etching machine, 3D printer and different gadgets. There are 4 openings in the board for stepper engine drive modules, can drive 4 stepper engines, and each progression stepper engine just need two 10 port, in other words, 6 10 ports can great to oversee three stepper engine, its exceptionally advantageous to utilize. After embed Arm computer CNC Shield into Embedded System, and introduced GRBL firmware then rapidly DIY a CNC etching machine works.
STEPPER DRIVERS
Stepper drivers utilized as a part of proposed thought gives an incorporated engine driver answer for printers, scanners, and other computerized. The gadget has two H-connect Up to 1/16 Micro venturing drivers and a small scale venturing indexer, and is planned to drive a bipolar stepper engine. The yield driver piece comprises of N-channel control MOSFETs arranged as full H-scaffolds to drive the engine windings. The A4988 is equipped for driving up to 2.0A of current from each yield (with legitimate warmth sinking, at 12.0 V and 5.0 Amp).

REFERENCES :
[1] Jae Wook Jeon and Young Youl Ha, A Generalized Approach for the Acceleration and Deceleration of Industrial Robots and CNC Machine Tools, IEEE Transactions on Industrial Electronics, Vol. 47, No. 1, February 2000, pp. 133-139
[2] Rata, M. and Rata, G. (2015). Application with a xyplotter controlled by pic used in student laboratory works. In Advanced Topics in Electrical Engineering (ATEE), 2015 9th International Symposium on, 117120. doi:10.1109/ATEE.2015.7133684.
[3] Oberg, Erik; Jones, Franklin D.; Horton, Holbrook L.; Ryffel, Henry H. (1996), Green, Robert E.; McCauley, Christopher J., eds., Machinery's Handbook (25th ed.), New York, NY, USA: Industrial Press, ISBN 9780-8311-2575-2, OCLC 473691581.
[4] Max, A., Lasova, V., and Pusman, v. (2015). Enhancement of teaching design of CNC milling machines. Procedia - Social and Behavioral Sciences, 176, 571 577. doi:http://dx.doi.org/10.1016/j.sbspro.2015.01. 512. URL
http://www.sciencedirect.com/science/article/pii/S1877042815005492. International Educational Technology Conference, IETC 2014, 3-5 September 2014, Chicago, IL, USA.
[5] Allen G. Morinec, Power Quality Considerations for CNC Machines: Grounding, IEEE Transactions on Industrial Electronics, Vol. 38, No. 1, January/February 2002, pp. 3-11
[6] Camposaragna, M., Chatterton, S., Righettini, P., Riva, R., Strada, R., and Zappa, B. (2006). Design and development of a cartesian plotter as a way to teach mechatronics to mechanical engineering students. In IEEE Industrial Electronics, IECON 2006 - 32nd Annual Conference on, 44744479. doklO.l 109/IECON.2006.348078. [7] Fisher, D. and Hofmann, R. (2007). Cnc machining plastic injection mold plates in the classroom. In Frontiers In Education Conference
[7] Global Engineering: Knowledge Without Borders, Opportunities Without Passports, 2007. FIE 07. 37th Annual, S2A12S2A17.

3, SUMMARY OF THE INVENTION
In this invention, an idea of upgrading traditional Computer Numerical Control machines with additional features is proposed. This can be done by automating the process of gcode generation with the help of IoT platform. With these features this can be used even by non-skilled person also. Invention is able draw geometric diagrams, sketches and can also write text. Invention is able to plot with any writing apparatus like pen, pencil, sketch-pen etc. The invention converts any image to vector image which can be scaled too many times of its actual size, without loosing quality of image. This feature gives invention flexibility in work area. Android application used to give inputs makes it a easy to use and user friendly invention. Image to plotted processed in android application to rectify the involvement of computer system. This also rectifies the dependence on tooling engineer.
The proposed idea is makes the use of IoT platform to minimize the computer dependence of plotters and other CNC based machines. It minimizes the complexities in use of traditional CNC machines.

4. CLAIMS :
We claim that
1) The proposed system can plot 2D graphical data on a paper with pen or any other writing apparatus.
2) The android application used for this apparatus is able to extract edges of any image and threshold to convert image in binary form
3) The proposed apparatus can write text in font provided to it.
4) The proposed idea can replicate any human hand writing.
5) The proposed system is designed to work independent to general purpose computer system.
6) The apparatus can be used by non-skilled personnel.