Observations & Surprises
This project has been a very interesting journey researching a wide variety of invisible potential hazards, designing systems to measure invisible hazards, building wearable instrumentation and testing my environment to see what invisible hazards might be present.
It is probably obvious from the content of my blogs that I learned a lot, actually way too much to fit into a few blogs, but the big surprise for me was how much fun it was. I anticipated the usual thrill I get from designing things and making them work, but I did not foresee how much fun it would be to use the instrumentation to examine my environment. It is a bit like the first time you got to play with a magnifying glass – you just run around looking at absolutely everything in a new way. It was also surprising to me how many people around me took an interest and wanted to examine their own environments. Normally talking about my projects is a good way to elicit glazed looks of boredom, but with this project, so many people wanted to borrow instrumentation it was tough to hang onto it long enough to take my own measurements.
The Kit
I am very happy the EXP432P401R was the required processor module for this design challenge as I might not have discovered it otherwise. This module is a very powerful, very capable and cost-effective platform for applications like this and will definitely be a favourite choice for future projects. The development environment was very easy to learn and use, especially since there were good examples available for most of the functionality I wanted to implement.
The comprehensive kit of modules supplied with the challenge (thanks Texas Instruments and element14) really allowed a complete wireless instrument with LCD to be implemented without even having to use wires and cables. Normally building such a platform would be an ambitious undertaking on its own, but with these plug-and-play booster packs and existing software examples, it enables projects to start with a complete, highly functional system and go beyond just getting some computer hardware to work.
Highlights
I got to design a custom sensor booster pack and the clear documentation available from Texas Instruments allowed it to work flawlessly without rework, respin or modification. It is really worth taking the time to do the job well – the gratification (and relief 
) is immense.
I also got to design many 3D printed parts, continuing my mechanical design learning journey.
It has been a long project with many little problems to overcome, but all the things I've learned and all the things I've accomplished in this project have made it a truly fabulous experience.
This is probably my last blog during this challenge as I have other projects that need attention, but you never know – I certainly will continue to work on the system and use it – the novelty has not worn off yet.
I did want to publish the software I used in the project - for completeness. However, I don't claim any kind of quality for the software, it lacks error checking and handling among other issues. One feature I didn't mention in my other blogs is if the right switch is held down during boot, the sensor system will run stand-alone, without WiFi.
IHEF Sensor MQTT Publishing Firmware
// Invisible Hazardous Environmental Factors (IHEF) Monitoring System
// Gas sensor, UV measurement and MQTT publishing software
// by Doug Wong
// 2017 - 06
// rev 01
#include <SPI.h>
#include <WiFi.h>
#include <WifiIPStack.h>
#include <Countdown.h>
#include <MQTTClient.h>
#include <OneMsTaskTimer.h>
#include <LCD_SharpBoosterPack_SPI.h>
#include <Wire.h>
// network name also called SSID
char ssid[] = "AndroidAP"; //network name - this should be altered for your system ***
// network password
char password[] = "aaaaaa"; //network password - this should be altered for your system ***
// Cloud Settings
#define MQTT_MAX_PACKET_SIZE 100
#define SERVERURLLEN 14
#define IOTFSERVER "xxx.xxx.x.xx" //server URL - this should be altered for your system ***
char organization[] = "";
char typeId[] = "iotsample-ti-energia";
char pubtopic[] = "IHEF";
char deviceId[] = "000000000000";
char clientId[64];
uint8_t macOctets[6];
// DAS Variables
LCD_SharpBoosterPack_SPI myScreen;
int AlcPin = A11; //MQ3 - Alcohol
int COPin = A14; //MQ7 - Carbo Monoxide
int AQPin = A13; //MQ135 - Air Quality
int CO2Pin = A8; //CO2
int UVPin = A9; //Ultraviolet Light
int AlcValue = 0; //MQ3 - Alcohol
int COValue = 0; //MQ7 - Carbo Monoxide
int AQValue = 0; //MQ135 - Air Quality
int CO2Value = 0; //CO2
int UVValue = 0; //Ultraviolet Light
int AlcHpin = 31; //MQ3 Heater
int COHpin = 38; //MQ7 Heater
int AQHpin = 32; //MQ135 Heater
String AlcStr; //string to display alcohol value
String COStr; //string to display CO value
String AQStr; //string to display air quality value
String CO2Str; //string to display CO2 value
String UVStr; //string to display UV value
float AlcR; //floating point value for alcohol
float COR; //floating point value for CO
float AQR; //floating point value for air quality
float CO2R; //floating point value for CO2
float UVR; //floating point value for UV
float AlcS; //floating point value for saved alcohol
float COS; //floating point value for saved CO
float AQS; //floating point value for saved air quality
float CO2S; //floating point value for saved CO2
float UVS; //floating point value for saved UV
int SCTR = 0; //seconds counter
int PCTR = 0; //publish counter
int PubFlag = 0;
const int buttonPin = PUSH2; // the number of the pushbutton pin
int buttonState = 0; // variable for reading the pushbutton status
int WiFiFlag = 1; //flag to enable WiFi
char mqttAddr[SERVERURLLEN];
int mqttPort = 1883;
MACAddress mac;
WifiIPStack ipstack;
MQTT::Client<WifiIPStack, Countdown, MQTT_MAX_PACKET_SIZE> client(ipstack);
void setup() {
uint8_t macOctets[6];
// setup LCD to display sensor data
pinMode(AlcHpin, OUTPUT); //heater control pin
pinMode(COHpin, OUTPUT); //heater control pin
pinMode(AQHpin, OUTPUT); //heater control pin
// initialize the pushbutton pin as an input:
pinMode(buttonPin, INPUT_PULLUP);
// setup LCD to display sensor data
myScreen.begin();
myScreen.clearBuffer();
myScreen.setFont(0);
Serial.begin(115200);
// read the state of the pushbutton value:
buttonState = digitalRead(buttonPin);
//if the pushbutton is pressed on startup disable WiFi
if (buttonState == LOW) {
WiFiFlag = 0;
}
if (WiFiFlag){
// attempt to connect to Wifi network:
myScreen.text(5, 1, "Connecting...");
myScreen.flush();
// Connect to WPA/WPA2 network. Change this line if using open or WEP network:
WiFi.begin(ssid, password);
while ( WiFi.status() != WL_CONNECTED) {
// flash + while we wait to connect
myScreen.text(86, 1, "+");
myScreen.flush();
delay(200);
myScreen.text(86, 1, " ");
myScreen.flush();
delay(100);
}
myScreen.text(5, 1, "WiFi Connected ");
myScreen.text(5, 16, "Waiting for ip");
myScreen.flush();
while (WiFi.localIP() == INADDR_NONE) {
// wait for an ip addresss
delay(300);
}
// We are connected and have an IP address.
myScreen.text(5, 1, "IP obtained");
myScreen.text(5, 16, WiFi.localIP());
mac = WiFi.macAddress(macOctets);
// Use MAC Address as deviceId
sprintf(deviceId, "%02x%02x%02x%02x%02x%02x", macOctets[0], macOctets[1], macOctets[2], macOctets[3], macOctets[4], macOctets[5]);
sprintf(clientId, "d:%s:%s:%s", organization, typeId, deviceId);
sprintf(mqttAddr, IOTFSERVER);
}
delay(400); //to allow the text to be read before erasing
myScreen.clear();
myScreen.text(5, 1, "STARTING DAS");
myScreen.flush();
delay(300); //to allow the text to be read before erasing
myScreen.clear();
myScreen.clearBuffer();
//display sensor labels
myScreen.setFont(1);
myScreen.text(5, 1, "SENSORS");
myScreen.setFont(0);
myScreen.text(5, 22, "Alc");
myScreen.text(5, 37, "CO");
myScreen.text(5, 52, "AQ");
myScreen.text(5, 67, "CO2");
myScreen.text(5, 82, "UV");
myScreen.flush();
}
void loop() {
int rc = -1;
if (SCTR >= 0 && SCTR < 60) //turn on alcohol heater for 60 seconds
digitalWrite(AlcHpin, 1); //turn on heater
digitalWrite(COHpin, 0); //turn off heater
digitalWrite(AQHpin, 0); //turn off heater
if (SCTR > 58 && SCTR < 120) //turn on CO heater for 60 seconds
{
digitalWrite(AlcHpin, 0); //turn off heater
digitalWrite(COHpin, 1); //turn on heater
digitalWrite(AQHpin, 0); //turn off heater
}
if (SCTR > 118 && SCTR < 180) //turn on AQ heater for 60 seconds
{
digitalWrite(AlcHpin, 0); //turn off heater
digitalWrite(COHpin, 0); //turn off heater
digitalWrite(AQHpin, 1); //turn on heater
}
SCTR++; //increment seconds counter
PCTR++; //increment publish counter
if (SCTR > 179) //reset seconds counter
{
SCTR = 0;
}
if (PCTR > 6) //reset publish counter
{
PCTR = 0;
}
//Read Sensors
AlcValue = analogRead(AlcPin); //read Alcohol sensor
COValue = analogRead(COPin); //read CO sensor
AQValue = analogRead(AQPin); //read Air Quality sensor
CO2Value = analogRead(CO2Pin); //read CO2 sensor
UVValue = analogRead(UVPin); //read UV sensor
AlcR = (float)AlcValue;
COR = (float)COValue;
AQR = (float)AQValue;
CO2R = (float)CO2Value;
UVR = (float)UVValue;
if (SCTR == 178) //save good alcohol reading
{
AlcS = AlcR;
}
if (SCTR == 118) //save good CO reading
{
COS = COR;
}
if (SCTR == 58) //save good AQ reading
{
AQS = AQR;
}
AlcStr = String(AlcValue); //convert reading to ASCII for display
COStr = String(COValue); //convert reading to ASCII
AQStr = String(AQValue); //convert reading to ASCII
CO2Str = String(CO2Value); //convert reading to ASCII
UVStr = String(UVValue); //convert reading to ASCII
myScreen.setFont(0);
myScreen.text(40, 22, AlcStr + " "); //display alcohol
myScreen.text(40, 37, COStr + " "); //display CO
myScreen.text(40, 52, AQStr + " "); //display Air Quality
myScreen.text(40, 67, CO2Str + " "); //display CO2
myScreen.text(40, 82, UVStr + " "); //display UV
myScreen.text(70, 22, "ppm"); //display units
myScreen.text(70, 37, "ppm"); //display units
myScreen.text(70, 52, "ppm"); //display units
myScreen.text(70, 67, "ppm"); //display units
myScreen.text(70, 82, "idx"); //display units
myScreen.flush();
delay (1000);
if (WiFiFlag) {
if (PCTR == 5) //publish on the 5th second of every 6 seconds
{
if (!client.isConnected()) {
// if (WiFi.status() == WL_CONNECTED) {
while (rc != 0) {
rc = ipstack.connect(mqttAddr, mqttPort);
}
MQTTPacket_connectData connectData = MQTTPacket_connectData_initializer;
connectData.MQTTVersion = 3;
connectData.clientID.cstring = clientId;
rc = -1;
while ((rc = client.connect(connectData)) != 0)
;
}
//make up messages to publish data and send
char ALCjson[12] = "Alc: ";
dtostrf(AlcS,1,2, &ALCjson[5]);
// ALCjson[1] = '{';
ALCjson[10] = '}';
ALCjson[11] = '\0';
MQTT::Message message;
message.qos = MQTT::QOS0;
message.retained = false;
message.payload = ALCjson;
message.payloadlen = strlen(ALCjson);
rc = client.publish(pubtopic, message);
if (rc != 0) {
// error code processing
}
char COjson[12] = "CO : ";
dtostrf(COS,1,2, &COjson[5]);
// COjson[1] = '{';
COjson[10] = '}';
COjson[11] = '\0';
message.payload = COjson;
message.payloadlen = strlen(COjson);
rc = client.publish(pubtopic, message);
if (rc != 0) {
// error code processing
}
char AQjson[12] = "AQ: ";
dtostrf(AQS,1,2, &AQjson[5]);
// AQjson[1] = '{';
AQjson[10] = '}';
AQjson[11] = '\0';
message.payload = AQjson;
message.payloadlen = strlen(AQjson);
rc = client.publish(pubtopic, message);
if (rc != 0) {
// error code processing
}
char CO2json[12] = "CO2: ";
dtostrf(CO2R,1,2, &CO2json[5]);
// CO2json[1] = '{';
CO2json[10] = '}';
CO2json[11] = '\0';
message.payload = CO2json;
message.payloadlen = strlen(CO2json);
rc = client.publish(pubtopic, message);
if (rc != 0) {
// error code processing
}
char UVjson[12] = "UV: ";
dtostrf(UVR,1,2, &UVjson[5]);
// UVjson[1] = '{';
UVjson[10] = '}';
UVjson[11] = '\0';
message.payload = UVjson;
message.payloadlen = strlen(UVjson);
rc = client.publish(pubtopic, message);
if (rc != 0) {
// error code processing
}
}
}
}
IHEF MQTT Subscriber Firmware
/*
Invisible Hazardous Environmental Factors
by Doug Wong 2017-04-08
Remote Display via MQTT
- connects to an MQTT server
- subscribes to the topic "IHEF"
- displays Alcohol, CO, Air Quality, CO2, UV
*/
#include <SPI.h>
#include <WiFi.h>
#include <PubSubClient.h>
#include <LCD_SharpBoosterPack_SPI.h>
// your network name also called SSID
char ssid[] = "aaaaaa"; //network name – change to your system ***
// your network password
char password[] = "aaaaaa"; //network password – change to your system***
// MQTTServer to use
char server[] = "xxx.xxx.x.xx"; //server URL – change to your system***
// String dstring;
String astring;
char dchar[22];
LCD_SharpBoosterPack_SPI myScreen;
//callback section retrieves subscribed data and displays it
void callback(char* topic, byte* payload, unsigned int length) {
char *cstring = (char *) payload;
char *dstring = (char *) payload;
for (int i=0; i<=10; i++) {
dstring[i] = cstring[i];
}
if (cstring[1] == 108) // ALC
{
myScreen.text(5, 17, dstring);
myScreen.text(65, 17, " ppm ");
}
if (cstring[2] == 32) // CO
{
myScreen.text(5, 32, dstring);
myScreen.text(65, 32, " ppm ");
}
if (cstring[1] == 81) // AQ
{
myScreen.text(5, 47, dstring);
myScreen.text(65, 47, " ppm ");
}
if (cstring[2] == 50) // CO2
{
myScreen.text(5, 62, dstring);
myScreen.text(65, 62, " ppm ");
}
if (cstring[0] == 85) // UV
{
myScreen.text(5, 77, dstring);
myScreen.text(65, 77, " idx ");
}
myScreen.flush();
}
WiFiClient wifiClient;
PubSubClient client(server, 1883, callback, wifiClient);
void setup()
{ //initiallization section connects to MQTT broker
Serial.begin(115200);
// attempt to connect to Wifi network:
myScreen.begin();
myScreen.clearBuffer();
myScreen.setFont(0);
myScreen.text(5, 1, "Connecting...");
myScreen.flush();
// Start Ethernet with the build in MAC Address
// attempt to connect to Wifi network:
// Connect to WPA/WPA2 network
WiFi.begin(ssid, password);
while ( WiFi.status() != WL_CONNECTED) {
// print dots while we wait to connect
delay(300);
}
myScreen.text(5, 9, "WiFi Connected ");
myScreen.text(5, 18, "Waiting for ip");
myScreen.flush();
while (WiFi.localIP() == INADDR_NONE) {
delay(300);
}
myScreen.text(5, 27, "IP obtained");
myScreen.text(5, 36, WiFi.localIP());
myScreen.flush();
delay(300);
}
void loop()
{
// Reconnect if the connection was lost
if (!client.connected()) {
if(!client.connect("IHEF")) {
} else {
if(client.subscribe("IHEF")) {
myScreen.text(5, 45, "Subcribed");
myScreen.text(5, 54, "IHEF");
myScreen.flush();
delay(1200);
myScreen.clear();
myScreen.text(20, 3, "MQTT IHEF");
myScreen.flush();
}
}
}
// Check if any message were received
// on the topic we subscribed to
client.poll();
delay(1000);
}
It has been fun and informative reading other entries in this challenge, and interacting with participants, I hope everyone enjoyed it as much as I did.
Links to all blogs and videos that document this project are listed here:
Safe and Sound - Invisible Hazardous Environmental Factors Monitoring System - blog 1 of 22 - blog 1
Safe and Sound - Hazardous Factors System - Development Plan - blog 2
Safe and Sound - Hazardous Factor - UV Light - blog 3
Safe and Sound - Hazardous Factor - Air Quality - blog 4
Safe and Sound - Hazardous Gasses PCB - blog 5
Safe and Sound - Hazardous Factor - Radon - blog 6
Safe and Sound - Invisible Hazards System - Kit Unboxing - blog 7
Safe and Sound - MSP-EXP432P401 & Sharp LCD - blog 8
Safe and Sound - Hazardous Factors MQTT Broker - blog 9
Safe and Sound - Hazardous Factors Sensor PCB - blog 10
Safe and Sound - Hazardous Environmental Factors - ELF - blog 11
Safe and Sound - Hazardous Factors MQTT Subscriber & Publisher - blog 12
Safe and Sound - Hazardous Factors System - ARM Car - blog 13
Safe and Sound - Environmental Factors - Wearables - blog 14
Safe and Sound - Environmental Factors - Microwaves - blog 15
Safe and Sound - Environmental Factors - GAS Sensors - blog 16
Safe and Sound - Hazardous Factors Monitoring System - Gas Sensors Module - blog 17
Safe and Sound - Invisible Hazardous Environmental Factors Monitoring System - blog 18
Safe and Sound - Cell Phone Shield Test - blog 19
Safe and Sound - Invisible Hazards Project Spin-offs - blog 20
Safe and Sound - Gas Sensor Demo - blog 21
Safe and Sound - Ultraviolet Light Tests - blog 22
Safe and Sound - Invisible Hazardous Environmental Factors Monitoring System Conclusions - blog 23
MSP-EXP432P401R Publishing Sensor Data to an MQTT Broker
Safe and Sound Hazardous Factors Sensor PCB
Wearable Environmental Factors Instruments
Invisible Hazardous Environmental Factors System
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