Drawing robot capable of rendering SVG paths over WebSockets. Powered by a Raspberry Pi running Node.js.

• Motor Mounts (two of each)
• Electronics Case
• Pen Holder Gondola
• Servo Horn Extension

• NEMA 17 Stepper Motors, 36.8oz.in 12v 0.4a (need 2) - $23.98
• Suction Cup with Quick Release (x2) - $5.98
• Spiderwire 80-pound fishing line - $17.56
• Micro USB cable 10-ft. 2-pack - $8.99
• Micro USB breakout 10-pcs (only need 2) - $6.59
• USB type a female breakout 2-pack - $4.50
• Raspberry Pi Zero W - $10)
• Easydriver Stepper Motor Driver (2-pack) - $9.99
• SG92R Micro Servo motor - $6.99
• 6003zz bearing 17x35x10 (need 2) - $11
• 10pcs 500mm 3-pin servo extensions (need several) - $7.69
• 2.1mm x 5.5mm barrel jack 15pcs (need 1) - $7.59
• 12v 1a power adapter 2.1mm/5.5mm lead - $9.99
• USB Micro Power Adapter - $5.99
• Pololu Universal Mounting Hub for 5mm shaft, #4-40 holes (2-pack) - $11.44
• USB fan (40mm) - $7.99
• #8-32 x 1-5/8 in. Eye Bolts (2-pack) - $0.98
• 8 screws for spools (#4-40 x ~½")
• 8 screws for motors (M3-.50 x 6mm metric machine screws)
• 1-2 small screws for gondola to secure pen/marker
• Mounting Putty - $4.87
• Standard wire or jumper wires (and headers for components if using jumpers)
• Dry erase markers (or other drawing implements)
• Micro SD card (class 10 or better)

Thank you to the kind people at the Johnson County Library's Black & Veatch MakerSpace for documenting the assembly process at instructables.com.

1. Download and install Etcher.
2. Download and install latest Raspbian OS and flash it onto your SD card with Etcher.
3. Enable SSH by adding a blank file named ssh (no extension) to the boot directory on the Pi's SD card. (Last tested with Raspbian Stretch Lite 2018-06-27 version.)
4. Set up Wifi by adding a file named wpa_supplicant.conf to the same boot directory with the following contents (replace MySSID and MyPassword with your credentials):

   ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev
   update_config=1
   	
   network={ 
   	ssid="MySSID" 
   	psk="MyPassword" 
   }
   

From a device connected to the same network as the Drawbot Pi, SSH into the Pi with ssh pi@raspberrypi.local. The default password is raspberry.

Then, on the Drawbot Pi:

1. Update, upgrade, and install NPM, Git. (Automatically answer "yes" to everything.):

   • sudo apt-get update
   • sudo apt-get upgrade
   • sudo apt-get install npm
   • sudo apt-get install git

2. Install Node.js.

   • sudo npm install -g n (Install n for node.js version management. github.com/tj/n)
   • sudo n stable (Install latest stable version of Node.js. Last tested with v10.8.0)

3. Upgrade NPM. (and remove old apt-get version).

   • sudo npm install npm@latest -g
   • sudo apt-get remove npm
   • sudo reboot (After rebooting, you'll have to SSH into the Pi again.)

4. Install pigpio C library. npmjs.com/package/pigpio

   • sudo apt-get install pigpio (Only if you're using Raspbian Lite.)
   • npm install pigpio

On the Drawbot Pi:

1. git clone https://github.com/andywise/drawbot.git to clone this repository.
2. cd drawbot
3. npm i

On the Drawbot Pi:

• Run npm start or sudo node draw.js to start the Drawbot controller.

On a device connected to the same local network as the Drawbot Pi:

• Go to raspberrypi.local/control to access the Drawbot control interface.
• Use the "bullseye" interface to manually position the gondola, or raise/lower the pen/marker.
• Use the settings panel to configure the Drawbot's D, X, and Y values (see "Configuration" below).
• Drag and drop an SVG file onto the control interface to send artwork to the Drawbot!

• Only the first <path> element will be drawn, so if necessary, combine artwork into a single compound path.
• The Drawbot will scale artwork so that 1 pixel = 1 millimeter.

• Enter value for D: measure distance between string starting points (in millimeters).
• Enter starting X and Y values: measure distance from left and top (respectively) of left string starting point to initial pen position (also in mm).
• Note: Values will be stored in the config.json file.

• For now, go check out "TSP Art."