---
title: 'ESP8266 Medicine Indicator Light'
date: 2023-10-13T15:49:14-04:00
tags: ["diy", "tutorial", "esp"]
author: "Me"
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description: 'Learn how to make an ESP8266 and a few simple components into an indicator light.'
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cover:
    image: "esp_medicine_indicator.png"
    alt: "ESP8266 Logo with a Medicine Icon, Colorized"
    caption: "Learn how to turn an ESP8266 device into an indicator light"
    relative: false
    hidden: true
---

This is a quick treat! We recently learned that one of our children needs to take medicine twice a day for the foreseeable
future. He's too young to take it on his own, and the morning and evening responsibility are split up between my partner and
I, so we needed some sort of indicator to let the other know if the previous dose was (or wasn't!) taken. Naturally, I sprung
into action with an ESP device and some leftover components.

## Device Overview

The device works like this (see the pictures below): Two [single neopixel LEDs](https://www.adafruit.com/product/1260) and a
non-latching button are connected to the ESP8266. Inside the code there is a switch-case section which changes case per
button press. On each press, the light will change depending on what is setup for that case. At the same time, each case is
establishing a value for `morning` and `evening` which will be given a value of 0 or 1 - 0 to indicate that the medicine was
not taken, and 1 to indicate that it was taken. Along with the time server data, I send an MQTT payload to my [MQTT Broker,
Mosquitto](https://mosquitto.org/).

Here's what the payload looks like:

```json
{
  "time": "1630",
  "morning": "1",
  "evening": "0"
}
```

## Thoughts and Background

I'd like to write a longer post that chops up to the code and goes into explanations of each section, but I'm running out of
time - work has been quite busy lately. If you'd like me to add a post with more code explanations, or just have questions,
feel free to mention me on [Mastoton/Fosstodon](https://fosstodon.org/@notnorm) and we can chat.

The much shorter explanation is that I didn't want this device to be an isolated device in my network. So what I did was
connected the ESP8266 to my wifi network and import an NTP (Network Time Protocol) server to ensure I get I have the current
time. Then, look at the state of the light, and construct and transmit an MQTT payload with the state of the light & time, so
that I can use it elsewhere.

What's neat about importing a time server is that at midnight, I reset both of the lights to red so that I don't have to
reset it manually when I get up in the morning.

In a separate post, I'll show how I use the MQTT payload in HomeAssistant to send [Pushover Notifications](https://pushover.net)
to me and my partner in case we forgot to give my child his medicine! What's great about this little project is that it is
scalable (add more components and sensors!) and that it doesn't need to indicate if someone has taken their medicine! You
could use the button to count how many times your dog (or child!) has gone to the bathroom, how many times to eat a snack or
drink water while working, and many more ideas.

Assuming everything has gone well for the day and we've given my child both of his doses, we should
be heading to bed with both of those lights being green. However, we'll want to take into account a few edge cases. See the
pictures below with quick explanations.

## Materials Used

Here is what I used to construct this:

* [ESP8266 Dev
  Board](https://www.amazon.com/HiLetgo-Internet-Development-Wireless-Micropython/dp/B081CSJV2V/ref=sr_1_1?crid=7JMC6TOMCS9I&keywords=hiletgo+esp8255&qid=1697229200&sprefix=hiletgo+esp8255%2Caps%2C89&sr=8-1) - I tend to like HiLetgo from Amazon.
* 22 AWG Solid Wire
* White Ping Pong ball - Cut in half
* Balsa Wood
* [Tactile Button Switch](https://www.adafruit.com/product/367)
* [Adafruit Flora RGB NeoPixel](https://www.adafruit.com/product/1260)

## Pictures

![Front of Device with one light green, the other red](../posts/img/esp_indicator_1.png)
![Front of Device with both lights green](../posts/img/esp_indicator_2.png)
![Front of Device with both lights red](../posts/img/esp_indicator_3.png)
![Underside of device with wires](../posts/img/esp_indicator_wires.png)

## Full Code

```c++
#include <Wire.h>
#include <Adafruit_NeoPixel.h>
#include <ESP8266WiFi.h>
#include <NTPClient.h>
#include <WiFiUdp.h>
#include <PubSubClient.h>
#include <ArduinoJson.h>
#include <secrets.h>

#define NEO_PIN 14  // Pin for all the Neopixels
#define SIG_PIX 2  // Number of temperature pixels
#define BUTTON_FWD_PIN 4
#define mqtt_topic "home/medicine"

const char* ssid = WIFI_SSID;
const char* password = WIFI_PASS;
const char* mqtt_server = MQTT_SERV;
const char* mqtt_user = MQTT_USER;
const char* mqtt_password = MQTT_PASS;

boolean oldState = HIGH;
int mode = 0; // Active mode on startup

// NTP Definition
// const long utcOffsetInSeconds = -18000;
const long utcOffsetInSeconds = -14400;
//char daysOfTheWeek[7][12] = {"Sunday", "Monday", "Tuesday", "Wednesday", "Thursday", "Friday", "Saturday"};
WiFiUDP ntpUDP;
NTPClient timeClient(ntpUDP, "north-america.pool.ntp.org", utcOffsetInSeconds);

WiFiClient espClient;
PubSubClient client(espClient);

long lastMsg = 0;
char msg[50];
float value = 0;

char morning_status[] = "false";
char evening_status[] = "false";
char current_time[] = "";

Adafruit_NeoPixel NeoJewel = Adafruit_NeoPixel(SIG_PIX, NEO_PIN, NEO_GRB + NEO_KHZ800);
unsigned long delayTime;

// Taken Medicine Color
uint32_t pineGreen = NeoJewel.Color(14, 170, 26);
// Not Yet Taken Color
uint32_t pureRed = NeoJewel.Color(255, 0, 0);

void setup() {
  delayTime = 1000;
  Serial.begin(9600);
  delay(500);

  while (!Serial) {
    ; // wait for serial port to connect. Needed for native USB port only
  }

  Serial.println("Attempting to connect to SSID: ");
  Serial.print(ssid);
  WiFi.begin(ssid, password);

  // Attempt to connect to WiFi network:
  while (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());   //You can get IP address assigned to ESP
  Serial.println("Mac Address: ");
  Serial.println(WiFi.macAddress());
  delay(100);
  client.setServer(MQTT_SERV, MQTT_PORT);
  WiFi.setAutoReconnect(true);
  WiFi.persistent(true);

  // Necessary code for NeoPixel setup
  pinMode(BUTTON_FWD_PIN, INPUT_PULLUP);

  //Initialization of the Jewel
  NeoJewel.setBrightness(100);
  NeoJewel.begin();
  NeoJewel.clear();
  NeoJewel.show();
}

void loop() {
  boolean newState = digitalRead(BUTTON_FWD_PIN);
  if((newState == LOW) && (oldState == HIGH)) {
    delay(30);
    newState = digitalRead(BUTTON_FWD_PIN);
    if(newState == LOW) {
      if(++mode > 4) mode = 0;
      switch(mode) {
        case 0:
        // Nothing Taken
          { NeoJewel.clear();
          NeoJewel.fill(pureRed, 0, 2);
          NeoJewel.show();
          String morning_status = "false";
          String evening_status = "false";
          Serial.println(morning_status + evening_status);
          break; }
        case 1:
        // Morning Taken
          { NeoJewel.clear();
          NeoJewel.fill(pineGreen, 0, 1);
          NeoJewel.fill(pureRed, 1, 2);
          NeoJewel.show();
          String morning_status = "true";
          String evening_status = "false";
          Serial.println(morning_status + evening_status);
          break; }
        case 2:
        // Evening Taken
          { NeoJewel.clear();
          NeoJewel.fill(pineGreen, 1, 2);
          NeoJewel.fill(pureRed, 0, 1);
          NeoJewel.show();
          String morning_status = "false";
          String evening_status = "true";
          Serial.println(morning_status + evening_status);
          break; }
        case 3:
        // Both Taken
          { NeoJewel.clear();
          NeoJewel.fill(pineGreen, 0, 2);
          NeoJewel.show();
          String morning_status = "true";
          String evening_status = "true";
          Serial.println(morning_status + evening_status);
          break; }
      }
    }
  }
  // Set the last-read button state to the old state (reset)
  oldState = newState;

  if (WiFi.status() != WL_CONNECTED) {
    delay(1000);
    WiFi.disconnect();
    ESP.restart();
  }

}

void publishmqtt(String current_time, String morning_status, String evening_status) {
    StaticJsonDocument<200> doc;

    doc["time"] = (String)current_time;
    doc["morning"] = (String)morning_status;
    doc["evening"] = (String)evening_status;
    serializeJsonPretty(doc, Serial);

    char data[200];
    Serial.println(data);
    Serial.println("");
    serializeJson(doc, data);
    client.publish(mqtt_topic, data, true);
    delay(2000);
    yield();
}

void reconnect() {
  // Loop until we're reconnected
  while (!client.connected()) {
    Serial.println("Connecting to MQTT...");
    // Create a random client ID
    String clientId = "ESP8266Client-";
    clientId += String(random(0xffff), HEX);
    if (client.connect(clientId.c_str(), mqtt_user, mqtt_password)) {
      Serial.println("connected");
    } else {
      Serial.println("failed with state ");
      Serial.print(client.state());
      delay(2000);
      ESP.restart();
    }
  }
}
```