robot.py

from Adafruit_Thermal import *
import RPi.GPIO as GPIO
import time
import os
from PIL import Image
import subprocess
import select
import socket
import errno


# GPIO PINS
BUTTON_HALT = 6
BUTTON_PRINT = 5
READY_LED = 4
BUSY_LED = 27
PRINTING_LED = 17

EYE_1_LED = 18
EYE_2_LED = 22

# Store the print number in a text file so it persists between boots
global imageNum
imageNum = 1
with open ('imageNum.txt', 'r') as readFile:
    val = readFile.read()
    imageNum = int(val) + 1
    readFile.close()

print("imagNum: " + str(imageNum))


# Init GPIO states
GPIO.setmode(GPIO.BCM)
GPIO.setup(READY_LED, GPIO.OUT)
GPIO.setup(BUSY_LED, GPIO.OUT)
GPIO.setup(PRINTING_LED, GPIO.OUT)
GPIO.setup(EYE_1_LED, GPIO.OUT)
GPIO.setup(EYE_2_LED, GPIO.OUT)
GPIO.setup(BUTTON_PRINT, GPIO.IN, pull_up_down=GPIO.PUD_UP)
GPIO.setup(BUTTON_HALT, GPIO.IN, pull_up_down=GPIO.PUD_UP)

GPIO.output(READY_LED, GPIO.LOW)
GPIO.output(PRINTING_LED, GPIO.HIGH)


# Socket server is used to communicate with the Processing app that generates the images
print('starting socket server...')
HOST = ''
PORT = 5204
s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

s.bind((HOST, PORT))
s.listen(1)

GPIO.output(BUSY_LED, GPIO.HIGH)
IMAGE_OUTPUT_FILE = "build/application.linux-armv6hf/output/image.png"


# launch processing app as subprocess
print('launching p5')
subprocess.Popen(['xvfb-run', 'build/application.linux-armv6hf/build'])

conn, addr = s.accept()
conn.setblocking(False)
print('Connected by', addr)

printer = Adafruit_Thermal("/dev/ttyUSB0", 9600, timeout=5)

# Flash the eye LEDs in a pattern
def flashEyes():
    GPIO.output(EYE_1_LED, GPIO.LOW)
    GPIO.output(EYE_2_LED, GPIO.LOW)
    time.sleep(0.5)
    GPIO.output(EYE_1_LED, GPIO.HIGH)
    time.sleep(0.3)
    GPIO.output(EYE_1_LED, GPIO.LOW)
    GPIO.output(EYE_2_LED, GPIO.HIGH)
    time.sleep(0.3)
    GPIO.output(EYE_1_LED, GPIO.HIGH)
    GPIO.output(EYE_2_LED, GPIO.LOW)
    time.sleep(0.3)
    GPIO.output(EYE_1_LED, GPIO.LOW)
    GPIO.output(EYE_2_LED, GPIO.HIGH)
    time.sleep(0.3)
    GPIO.output(EYE_1_LED, GPIO.LOW)
    GPIO.output(EYE_2_LED, GPIO.LOW)
    time.sleep(0.5)
    GPIO.output(EYE_1_LED, GPIO.HIGH)
    GPIO.output(EYE_2_LED, GPIO.HIGH)
    

# move the printed image to the archive folder
def archiveImage(num):
    filename = "archive/image-" + str(num) + ".png"
    os.rename(IMAGE_OUTPUT_FILE, filename)
    with open ('imageNum.txt', 'w') as file:
        file.write(str(imageNum))
        file.close()


# print the image (and text)
def doPrinting(num):
    print("doPrinting()")
    GPIO.output(READY_LED, GPIO.LOW)
    GPIO.output(BUSY_LED, GPIO.HIGH)
    
    GPIO.output(BUSY_LED, GPIO.LOW)
    GPIO.output(PRINTING_LED, GPIO.HIGH)
    
    try:
        img = Image.open(IMAGE_OUTPUT_FILE)
    except:
        showErrorState("ERROR: No image found")
        return
    
    # MAX CHARS: 32 "12345678901234567890123456789012"
    printer.println("SPRING FOR ZINES!  April 8, 2018")
    printer.println("--------------------------------")
    
    printer.printImage(img)
    
    printer.println("VOMIT COMIC #" + str(num))
    printer.println("www.cadinbatrack.com/vomit-comic")
    printer.feed(3)
    
    archiveImage(num)


# shut down the Pi safely
def shutdown():
    GPIO.output(READY_LED, GPIO.LOW)
    GPIO.output(BUSY_LED, GPIO.HIGH)
    GPIO.output(PRINTING_LED, GPIO.HIGH)
    GPIO.output(EYE_1_LED, GPIO.LOW)
    GPIO.output(EYE_2_LED, GPIO.LOW)
    os.system("sudo halt")


def showErrorState(e):
    print(e)
    GPIO.output(READY_LED, GPIO.LOW)
    
    GPIO.output(PRINTING_LED, GPIO.LOW)
    GPIO.output(BUSY_LED, GPIO.HIGH)
    time.sleep(0.5)
    GPIO.output(PRINTING_LED, GPIO.HIGH)
    GPIO.output(BUSY_LED, GPIO.LOW)
    time.sleep(0.5)
    GPIO.output(PRINTING_LED, GPIO.LOW)
    GPIO.output(BUSY_LED, GPIO.HIGH)
    time.sleep(0.5)
    GPIO.output(PRINTING_LED, GPIO.HIGH)
    GPIO.output(BUSY_LED, GPIO.LOW)
    time.sleep(0.5)
    GPIO.output(BUSY_LED, GPIO.HIGH)
    GPIO.output(PRINTING_LED, GPIO.HIGH)
    time.sleep(2)
    
    if e != "":
        printer.println(e)
        printer.feed(2)
    
    GPIO.output(PRINTING_LED, GPIO.LOW)
    GPIO.output(BUSY_LED, GPIO.LOW)
    

systemIsReady = True
def showReadyState():
    flashEyes()
    GPIO.output(BUSY_LED, GPIO.LOW)
    GPIO.output(PRINTING_LED, GPIO.LOW)
    GPIO.output(READY_LED, GPIO.HIGH)
    global systemIsReady
    systemIsReady = True


time.sleep(1)
showReadyState()

print('entering loop"')

try:
    print('try')
    while True:
        
        # get data from the socket connection
        data = ""
        try:
            data = conn.recv(1024)
        except IOError as e:
            if e.errno == errno.EWOULDBLOCK:
                pass
        
        # if Processing generated an image, print it
        if data == "image ready":
            print("image ready")
            flashEyes()
            doPrinting(imageNum)
            imageNum += 1
            showReadyState()
        
        # get input states from the button GPIO pins
        input_state = GPIO.input(BUTTON_PRINT)
        halt_state = GPIO.input(BUTTON_HALT)
    	
    	# print button pressed
        if input_state == False:
            time.sleep(0.2)
            print("button")

            GPIO.output(READY_LED, GPIO.LOW)
            GPIO.output(BUSY_LED, GPIO.HIGH)
            
            #send message to Processing 
            conn.send("generate image")
            
        
    	# halt (shutdown) button pressed
        if halt_state == False:
            startTime = time.time()
            time.sleep(0.2)
            
            # only start shutdown if the halt button is held for 2 seconds
            while GPIO.input(BUTTON_HALT) == GPIO.LOW:
                time.sleep(0.1)
                length = time.time() - startTime
                if length > 2:
                  shutdown()
        time.sleep(0.1)
 
# cleanup GPIO and socket connection before quitting             
finally:
    print('finally')
    GPIO.cleanup()
    conn.close()

I am trying to reproduce your incredilble vomit comic robot. I managed to generate random comics in processing, that I installed on my rpi3.
But now I'm having trouble seeing how to get them printed. I've downloaded this script, and put it in home/py. But when I launch it, I get the error```
File "/home/pi/random-comic-master/robot.py", line 25, in
with open ('imageNum.txt', 'r') as readFile:
FileNotFoundError: [Errno 2] No such file or directory: 'imageNum.txt'

Where should this imageNum be located?

Thanks!

@virginiebjt I don't have my Pi handy to check, but I think it should go in the same directory as the Python script.
imageNum.txt is just a plain text file that keeps track of the image number, so just start by putting 0 in there.

You could also get rid of those parts if you don't care about printing out the image number or saving all the images that were generated. Without it, the saved image will just overwrite the previous image.