Coffee Monitor Imp

client.nut

light <- hardware.pin8;
light.configure(ANALOG_IN);

was_brewing <- false;
brew_light <- 45000;

poll_time <- 30;
skip_updates <- 10;
until_heartbeat <- 0;

imp.setpowersave(true);

function notify(brewing, level) {
  until_heartbeat = skip_updates;
  agent.send("status", {
    "brewing": brewing,
    "light": level,
    "power":  hardware.voltage()
  });
}

function check() {
  local lvl = light.read();
  local brewing = false;
  
  if (lvl < brew_light) {
    brewing = true;
  }
  
  if (until_heartbeat < 1 || brewing != was_brewing)
    notify(brewing, lvl);
  else
    until_heartbeat--;
    
  was_brewing = brewing;
  imp.wakeup(poll_time, check);
}

imp.onidle(function() {
  server.log("sleeping");
  server.expectonlinein(poll_time * skip_updates);
});

check();

server.nut

was_brewing <- false;
slack_url <- "https://hooks.slack.com/services/blahblah";

function slack(msg) {
  server.log(msg);
  local body = "{\"text\": \""+msg+"\", \"username\": \"Coffeebot\", \"icon_emoji\": \":coffee:\"}";
  local resp = http.post(slack_url, {}, body).sendsync();
  server.log("Slack says ("+resp.statuscode + "): " + resp.body)
}

function spreadsheet() {
  local url = "https://docs.google.com/forms/blahblah/formResponse"
  local resp = http.post(url, {}, "ifq&submit=Submit").sendsync();
  server.log("Google says "+resp.statuscode)
}

function done() {
  slack("Coffee is ready!");
}

device.on("status", function (info) {
  server.log(format("brewing: %s (light: %d). voltage:  %.3fv", info["brewing"].tostring(), 0xffff - info["light"], info["power"]));

  if (info["power"] < 3.25) {
    slack("Uh-oh, batteries might be getting low: " + info["power"].tostring());
  }
  
  if (info["brewing"]) { //brewing!
    if (!was_brewing) {
      slack("Coffee is brewing...");
      spreadsheet();
    }
    was_brewing = true;
  } else {
    if (was_brewing) {
      server.log("finished brewing, waiting for drip...");
      imp.wakeup(60, done);
    }
    was_brewing = false;
  }
});