In August 2021, I got an idea to make a robot be able to draw pictures on a wall. After many days researching, designing, and programming, I finally finished a robot that could draw any pattern on a wall.My key-point in design is using general parts to make robot, so end-users can easily renew parts if repairing is needed. Body frame, motor, bolts and nuts, … are all easily found on the market. Main controller is well-known PCB Arduino Mega compatible with CNC Shield to control two stepper motors that allow robot can traverse by belt.Step 1: Part List to PrepareArduino Mega 2560 x 1pcCNC shield x 1pcPower supply PCB x 1pcSD card module x 1pcStepper motor (traverse) x 2pcsGear (for belt) x 2pcsStepper motor (pen) x 1pcBelt x 2pcsBase x 1setBolt, nuts (various)SoftwareArduino IDE/ Corel draw/ Microsoft excelStep1. Install the robotIt takes about 1 hours to assemble the robot.The first layer is used to install Arduino, CNC shield, power supply.The second layer will be installed motor, SD cardNext step is prepare for pen-driver and put it to robotAnd the final layer is for the facePut the belt to motor gear and hang it on wall (need 2 nails hammered on wall). Overall, the robot looks like a jellyfish, it is swimming around the wall to make drawing :)Step 2. Code worksThe robot is based on Arduino code for Arduino Mega 2560 and it is open-source. Not like CNC machine which has X, Y axis perpendicular aligned and we can find x, y co-ordinate of target by tracking traverse distance of X, Y stepper motor.Detail code is here https://github.com/fumikrobot/source-codeThe wall drawing robot is hung on wall by 2 nails, we have to find target co-ordinate x1, y1 (of pen) by factor of belt tension (t1, t2), gravity (t3), distance of belt (a, c). Arduino code will help us to solve mathematic problem to find exact current location of pen to make exact drawingStep 3. Prepare for drawingAfter hang robot on wall, we need to do calibration step by declare to Arduino code the distance of two nails. Then, we will prepare drawing as steps:3.1 Your Picture need to draw3.2 Convert picture to vector (*.svg file) by CorelDraw (or any other software support *.svg file)3.3 Convert vector file to code for Arduino (by excel, program by me)3.4 Copy code file to SD card3.5 Plug in SD card to robot and start drawing
