Hi all,
My final project is a speculative project.
Its purpose is to raise awareness around how many and how often people die from shootings in this country.
You can find my document here.
This is my code, which needs a lot more work, since it is the hardest part of the project:
/* -------------------------------------------------------------------------
ShootingsArtefact -- an artefact that reacts to the number of deaths by shooting in the US
using the the Adafruit HUZZAH ESP8266 WiFi microcontroller (can also work on other ESP8266 boards)
with numbers provided by http://www.gunviolencearchive.org/. LED on pin 15 shows status:
Steady on = One-time initialization
Fast flicker = Connecting to network, polling data
Slow blink = Symptoms predicted in forecast (24-48 hrs)
Blip ea. 4 sec = Symptoms not in forecast (sleeping)
----------------------------------------------------------------------------
Configure the code below with your WiFi credentials. Then visit
http://www.gunviolencearchive.org/ and look up the number you wish to display.
Copy the URL into the appropriate spot in the code below.
When changing the number to be displayed, you will need to dig through the page's HTML
source to find a string that uniquely identifies the condition sought, while
avoiding false positives. See additional notes later in the code.
----------------------------------------------------------------------------*/
#include
#define LED_PIN 13 // LED+ is connected here
#define POLL_INTERVAL (15 * 60) // Time between server queries (seconds)
#define FAIL_INTERVAL 30 // If error, time before reconnect (seconds)
#define READ_TIMEOUT 10000L // Client read timeout, milliseconds
char ssid[] = "AGH",
pass[] = "???",
host[] = "www.gunviolencearchive.org",
page[] = "/";
// This structure is used during string-matching operations. Only the
// 'string' element is initialized here; other elements are initialized
// or modified as needed in multiFind(). This code is NOT AVR-friendly;
// PROGMEM strings are not used, it's assumed this will be running on
// an ESP8266 (or ported to other non-AVR board that just normally puts
// const strings in program memory instead of RAM).
struct stringMatch {
const char * const string;
uint8_t stringLength;
uint8_t matchedLength;
} matchList0[] = {
{ "Number of Deaths1" },
{ NULL } // END OF LIST, don't remove this
}; // Can create add'l string match lists here if needed
WiFiClient client;
String readString;
int deathsThisYear;
void setup(void) {
pinMode(LED_PIN, OUTPUT);
digitalWrite(LED_PIN, HIGH); // Steady on = startup
Serial.begin(57600);
Serial.println("Hello!");
}
// STRING-MATCH FUNCTION -----------------------------------------------------
// multiFind() scans a connected Client object for one or more strings
// (NULL-terminated stringMatch array 'list'), returns index of the first
// string matched (0 to n-1) or -1 if timeout or no match.
static int8_t multiFind(struct stringMatch *list) {
uint32_t t;
char c;
uint8_t i;
// Reset all stringMatch items prior to search...
for(i=0; list[i].string; i++) {
list[i].stringLength = strlen(list[i].string);
list[i].matchedLength = 0;
}
for(t=millis();;) {
if(client.available()) { // Data pending from Client?
c = client.read(); // Read it
if(c == 0) break; // End of data reached, no match
for(i=0; list[i].string; i++) { // Compare against each stringMatch item...
if(c == list[i].string[list[i].matchedLength]) { // Matched another byte?
if(++list[i].matchedLength == // Matched whole string?
list[i].stringLength) return i; // WINNER, return index
} else { // Character mismatch, reset counter to start
list[i].matchedLength = 0;
}
}
t = millis(); // Reset timeout
} else if((millis() - t) > READ_TIMEOUT) {
Serial.println("Timeout");
break;
}
}
return -1; // No string match, or timeout
}
void loop() {
uint32_t t, hi, lo, pauseTime = FAIL_INTERVAL;
// Fast blink during WiFi connection...
analogWriteFreq(4); // 4 Hz
analogWrite(LED_PIN, 100); // ~10% duty cycle
Serial.print("WiFi connecting..");
WiFi.begin(ssid, pass);
while(WiFi.status() != WL_CONNECTED) {
Serial.write('.');
delay(500);
}
Serial.println("OK!");
// Slightly slower (but still quick) blink while searching
analogWriteFreq(1); // 1 Hz
analogWrite(LED_PIN, 100); // ~10% duty cycle
Serial.print("Contacting server...");
if(client.connect(host, 80)) {
Serial.print(F("OK\r\nRequesting data..."));
client.print("GET ");
client.print(page);
client.print(" HTTP/1.1\r\nHost: ");
client.print(host);
client.print("\r\nConnection: Close\r\n\r\n");
// multiFind() searches the incoming stream for a list of possible
// string matches, returning the index of the found item (or -1 if
// no match). Stream position will be immediately after the found
// item (allowing further searches to be performed from that point
// forward), or end of stream in -1 case.
// client.find() is the normal Arduino Stream search function, which
// looks for a single item. In this code, we're using multiFind()
// to skip past some of AccuWeather's false positives, to pick a
// starting point for a simple string search that more reliably
// indicates migraine weather in the forecast...
if((multiFind(matchList0) >= 0) &&
client.find("")) { // get past the last HTML before the number we want to capture)
// Found it -- number of kills this year.
Serial.println(F("FOUND"));
for (int i=0; i<6; i++){ // 5 digits and a comma, this will change in January when the count resets char c = client.read(); //gets one byte from serial buffer readString += c; //makes the String readString delay(2); //slow looping to allow buffer to fill with next character } if (readString.length() >0) {
Serial.print("Number of gun deaths in 2017 (as a string): ");
Serial.println(readString); //so you can see the captured String
readString.remove(2, 1); // remove comma (one character at index 2)
deathsThisYear = readString.toInt(); //convert readString into a number
readString="";
Serial.print("now as an integer: ");
Serial.println(deathsThisYear);
}
hi = lo = 500; // 1 Hz, 50% duty cycle
} else { // No match
Serial.println(F("not found"));
hi = 10; // Tiny blip
lo = 3990; // at about 1/4 Hz
}
// This is just one example...more complex code might need multiple
// find() and/or multiSearch() calls with different lists as a sort
// of decision tree.
Serial.println("Closing server connection.");
client.stop();
pauseTime = POLL_INTERVAL;
} else {
Serial.println("failed.");
}
// WiFi is turned off between server queries, to save a little power if
// you decide to make this battery-operated.
Serial.println("Stopping WiFi.");
WiFi.disconnect();
analogWrite(LED_PIN, 0);
// Delay until next server query time. The values of 'hi' and 'lo'
// determine the LED blink speed. This code doesn't use any low-power
// sleep techniques, as the ESP8266 doesn't appear to support PWM while
// sleeping...it has to be blinked in software.
Serial.print("Pausing for ");
Serial.print(pauseTime);
Serial.println(" seconds.");
t = millis();
while((millis() - t) < (pauseTime * 1000)) {
digitalWrite(LED_PIN, HIGH);
delay(hi);
digitalWrite(LED_PIN, LOW);
delay(lo);
}
}