DocWriter code

drive_google_doc.rb

# Dependencies: ruby-full, watir, xvfb, iceweasel, geckodriver
# Run `Xvfb :10 -ac &` before running this script

require 'watir'

NEW_DOC_URL = "https://docs.google.com/document/create"
EMAIL_ADDRESS = ENV['DOCWRITER_EMAIL']
PASSWORD = ENV['DOCWRITER_PASSWORD']
SHARE_WITH_EMAIL = ENV['DOCWRITER_SHARETO']

browser = Watir::Browser.new(:firefox)
browser.goto NEW_DOC_URL

el = browser.input(id: "identifierId")
el.wait_until_present
el.send_keys EMAIL_ADDRESS
btn = browser.div(id: "identifierNext")
btn.wait_until_present
btn.click

pswd = browser.input(name: "password")
pswd.wait_until_present
pswd.send_keys PASSWORD
btn = browser.div(id: "passwordNext")
btn.wait_until_present
btn.click

# Write the title
el = browser.input(class: "docs-title-input")
el.wait_until_present
el.click

until el.value.empty?
  el.send_keys :backspace
end

el.send_keys DateTime.now.new_offset(Rational(-4, 24)).strftime("%h %d, %Y - %I:%M%p")
el.send_keys :return

# Share the doc
el = browser.div(class: "jfk-button-action")
el.wait_until_present
el.click

sleep 2
iframe = browser.iframes.find {|i| i.class_name == "share-client-content-iframe"}

sleep 1
iframe.textarea(class: "apps-share-chips-input").send_keys SHARE_WITH_EMAIL

sleep 1
iframe.div(class: "simple-sharing-primary-button").click

cursor = browser.div(class: 'kix-cursor-caret')
cursor.wait_until_present

puts "READY"
$stdout.flush

table = {
  "0,0" => ",",
  "0,1" => "/",
  "0,2" => "1",
  "0,3" => "3",
  "0,4" => "7",
  "0,5" => "5",
  "0,6" => "-",
  "0,7" => "9",
  "1,0" => ".",
  "1,1" => "PLUSMINUS",
  "1,2" => "2",
  "1,3" => "4",
  "1,4" => "8",
  "1,5" => "6",
  "1,6" => "=",
  "1,7" => "0",
  "2,0" => "HALF",
  "2,1" => "q",
  "2,2" => "e",
  "2,3" => "t",
  "2,4" => "o",
  "2,5" => "u",
  "2,6" => "n",
  "2,7" => "v",
  "3,0" => ";",
  "3,1" => "z",
  "3,2" => "f",
  "3,3" => "h",
  "3,4" => "s",
  "3,5" => "k",
  "3,6" => "x",
  "3,7" => "c",
  "4,0" => "]",
  "4,1" => "w",
  "4,2" => "r",
  "4,3" => "y",
  "4,4" => "p",
  "4,5" => "i",
  "4,6" => "m",
  "4,7" => "b",
  "5,0" => "'",
  "5,1" => "a",
  "5,2" => "g",
  "5,3" => "j",
  "5,4" => "d",
  "5,5" => "l",
  "5,6" => "_SWITCH",
  "5,7" => "\t",
  "6,0" => " ",
  "6,1" => "\n",
  "6,2" => "W_OUT",
  "6,3" => "RELOC",
  "6,4" => "ALT",
  "6,5" => "\b",
  "6,6" => "CORRECT",
  "6,7" => "CODE",
  "7,0" => "SHIFT",
  "7,1" => "SHIFT_LOCK",
  "7,2" => "NC",
  "7,3" => "NC",
  "7,4" => "NC",
  "7,5" => "NC",
  "7,6" => "NC",
  "7,7" => "NC"
}

shiftTable = {
  "0,0" => ",",
  "0,1" => "?",
  "0,2" => "!",
  "0,3" => "#",
  "0,4" => "&",
  "0,5" => "%",
  "0,6" => "_",
  "0,7" => "(",
  "1,0" => ".",
  "1,1" => "CIRCLE",
  "1,2" => "@",
  "1,3" => "$",
  "1,4" => "*",
  "1,5" => "CENT",
  "1,6" => "+",
  "1,7" => ")",
  "2,0" => "QUARTER",
  "2,1" => "Q",
  "2,2" => "E",
  "2,3" => "T",
  "2,4" => "O",
  "2,5" => "U",
  "2,6" => "N",
  "2,7" => "V",
  "3,0" => ":",
  "3,1" => "Z",
  "3,2" => "F",
  "3,3" => "H",
  "3,4" => "S",
  "3,5" => "K",
  "3,6" => "X",
  "3,7" => "C",
  "4,0" => "}",
  "4,1" => "W",
  "4,2" => "R",
  "4,3" => "Y",
  "4,4" => "P",
  "4,5" => "I",
  "4,6" => "M",
  "4,7" => "B",
  "5,0" => "\"",
  "5,1" => "A",
  "5,2" => "G",
  "5,3" => "J",
  "5,4" => "D",
  "5,5" => "L",
  "5,6" => "_SWITCH",
  "5,7" => "\t",
  "6,0" => " ",
  "6,1" => "\n",
  "6,2" => "W_OUT",
  "6,3" => "RELOC",
  "6,4" => "ALT",
  "6,5" => "\b",
  "6,6" => "CORRECT",
  "6,7" => "CODE",
  "7,0" => "SHIFT",
  "7,1" => "SHIFT_LOCK",
  "7,2" => "NC",
  "7,3" => "NC",
  "7,4" => "NC",
  "7,5" => "NC",
  "7,6" => "NC",
  "7,7" => "NC"
}

consecutive_enter_count = 0
$stdin.each do |io|
  if io == "6,1\n"
    if consecutive_enter_count >= 1
      cursor.send_keys :return
      cursor.send_keys :return
      consecutive_enter_count = 0
    else
      cursor.send_keys " "
      consecutive_enter_count += 1
    end
  else
    cursor.send_keys io.include?("s") ? shiftTable[io.chomp.sub(/s/, '')] : table[io.chomp]
    consecutive_enter_count = 0
  end
end

read_typewriter_signals.c

// Compile with `gcc -Wall -o read_typewriter_signals read_typewriter_signals.c -lwiringPi`

#include <wiringPi.h>
#include <stdio.h>
 
int main(void) {
  wiringPiSetup();
  setbuf(stdout, NULL);

  int scanPins[] = {5, 22, 10, 11, 26, 27, 28, 29};
  int signalPins[] = {13, 12, 3, 2, 0, 7, 24, 23};
  
  int i = 0;
  int j = 0;
  for (i=0; i<8; i++) {
    pinMode(scanPins[i], INPUT);
    pinMode(signalPins[i], INPUT);
    pullUpDnControl(scanPins[i], PUD_UP);
    pullUpDnControl(signalPins[i], PUD_UP);
  }
  
  int keyDown[8][8] = {
    {0, 0, 0, 0, 0, 0, 0, 0},
    {0, 0, 0, 0, 0, 0, 0, 0},
    {0, 0, 0, 0, 0, 0, 0, 0},
    {0, 0, 0, 0, 0, 0, 0, 0},
    {0, 0, 0, 0, 0, 0, 0, 0},
    {0, 0, 0, 0, 0, 0, 0, 0},
    {0, 0, 0, 0, 0, 0, 0, 0},
    {0, 0, 0, 0, 0, 0, 0, 0}
  };

  int lastI;
  int lastJ;
  int sameKeyCount = 0;
  for (;;) {
    for (i=0; i<8; i++) {
      for (j=0; j<8; j++) {
        if (digitalRead(scanPins[i]) == LOW && digitalRead(signalPins[j]) == LOW) {
          (i == lastI && j == lastJ) ? sameKeyCount++ : sameKeyCount = 0;

          if (sameKeyCount > 50 && keyDown[i][j] <= 0) {
            printf("%d,%d\n", i, j);
            keyDown[i][j] = 50;
          }
          lastI = i;
          lastJ = j;
        }
        
        if (digitalRead(scanPins[i]) == LOW && digitalRead(signalPins[j]) == HIGH) {
          keyDown[i][j] = (keyDown[i][j] - 1);
        }
      }
    }
  }
}

startup.sh

#!/bin/bash

STATE="error";

while [  $STATE == "error" ]; do
  STATE=$(ping -q -w 1 -c 1 `ip r | grep default | cut -d ' ' -f 3` > /dev/null && echo ok || echo error)
  sleep 1
done

./read_typewriter_signals | ssh -t -t $CLOUD_USERNAME@$REMOTE_IP "DISPLAY=:10 ruby drive_google_doc.rb"

Run "startup.sh" by putting this line in /etc/rc.local per https://www.dexterindustries.com/howto/run-a-program-on-your-raspberry-pi-at-startup/:

sudo /home/pi/startup.sh &