#10 – ESP8266
Project #10: ESP8266 Thing – Precision RTC – Mk04
DS3231 Precision RTC FeatherWing
A Feather board without ambition is a Feather board without FeatherWings! This is the DS3231 Precision RTC FeatherWing: it adds an extremely accurate I2C-integrated Real Time Clock (RTC) with a Temperature Compensated Crystal Oscillator to any Feather main board. This RTC is the most precise you can get in a small, low power package. Most RTCs use an external 32kHz timing crystal that is used to keep time with low current draw.
With a CR1220 12mm lithium battery plugged into the top of the FeatherWing, you can get years of precision timekeeping, even when main power is lost. Great for datalogging and clocks, or anything where you need to really know the time.
DonLuc1901Mk03
1 x SparkFun ESP8266 Thing
1 x SparkFun FTDI Basic Breakout – 3.3V
1 x DS3231 Precision RTC FeatherWing
1 x RHT03 Humidity and Temperature Sensor
6 x Jumper Wires 3″ M/M
3 x Jumper Wires 6″ M/M
1 x Full-Size Breadboard
1 x SparkFun Cerberus USB Cable
SparkFun ESP8266 Thing
LG1 – Digital 5
RHT – Digital 4
SDA – Digital 2
SCL – Digital 14
GND – GND
VIN – +3.3V
DonLuc1901Mk03p.ino
// ***** Don Luc Electronics *****
// Software Version Information
// Project #10: SparkFun ESP8266 Thing – DS3231 Precision RTC - Mk04
// 01-03
// DonLuc1901Mk03p.ino 01-03
// SparkFun ESP8266 Thing
// DS3231 Precision RTC
// RHT03 Humidity and Temperature Sensor
// Include Library Code
// WiFi
#include <ESP8266WiFi.h>
// RHT Humidity and Temperature Sensor
#include <SparkFun_RHT03.h>
// DS3231 Precision RTC
#include <RTClib.h>
#include <Wire.h>
// WiFi Definitions
const char WiFiAPPSK[] = "donlucmk01";
// Pin Definitions
const int LED_PIN = 5; // Thing's onboard, green LED
const int ANALOG_PIN = A0; // The only analog pin on the Thing
const int DIGITAL_PIN = 12; // Digital pin to be read
// WiFi
WiFiServer server(80);
// RHT Humidity and Temperature Sensor
const int RHT03_DATA_PIN = 4; // RHT03 data pin Digital 4
RHT03 rht; // This creates a RTH03 object, which we'll use to interact with the sensor
float latestHumidity;
float latestTempC;
float latestTempF;
// DS3231 Precision RTC
RTC_DS3231 RTC;
String sDate;
String sTime;
void loop()
{
// RHT03 Humidity and Temperature Sensor
isRHT03();
// DS3231 Precision RTC
timeRTC();
// Check if a client has connected
WiFiClient client = server.available();
if (!client) {
return;
}
// Read the first line of the request
String req = client.readStringUntil('\r');
Serial.println(req);
client.flush();
// Match the request
int val = -1; // We'll use 'val' to keep track of both the request type (read/set) and value if set.
if (req.indexOf("/led/0") != -1)
val = 0; // Will write LED low
else if (req.indexOf("/led/1") != -1)
val = 1; // Will write LED high
else if (req.indexOf("/read") != -1)
val = -2; // Will print pin reads
// Otherwise request will be invalid. We'll say as much in HTML
// Set GPIO5 according to the request
if (val >= 0)
digitalWrite(LED_PIN, val);
client.flush();
// Prepare the response. Start with the common header:
String s = "HTTP/1.1 200 OK\r\n";
s += "Content-Type: text/html\r\n\r\n";
s += "<!DOCTYPE HTML>\r\n<html>\r\n";
// If we're setting the LED, print out a message saying we did
if (val >= 0)
{
s += "LED is now ";
s += (val)?"on":"off";
}
else if (val == -2)
{ // If we're reading pins, print out those values:
s += "Date = ";
s += sDate;
s += "<br>";
s += "Time = ";
s += sTime;
s += "<br>";
s += "Analog Pin = ";
s += String(analogRead(ANALOG_PIN));
s += "<br>"; // Go to the next line.
s += "Digital Pin 12 = ";
s += String(digitalRead(DIGITAL_PIN));
s += "<br>"; // Go to the next line.
s += "Humidity and Temperature";
s += "<br>"; // Go to the next line.
s += "Humidity : ";
s += String(latestHumidity); // Humidity
s += "%";
s += "<br>"; // Go to the next line.
s += "Celsius: ";
s += String(latestTempC); // Temperature *C
s += "*C";
s += "<br>"; // Go to the next line.
s += "Fahrenheit: ";
s += String(latestTempF); // Temperature *F
s += "*F";
}
else
{
s += "Invalid Request.<br> Try /led/1, /led/0, or /read.";
}
s += "</html>\n";
// Send the response to the client
client.print(s);
delay(1);
Serial.println("Client disonnected");
// The client will actually be disconnected when the function returns and 'client' object is detroyed
}
getRHT.ino
// RHT03 Humidity and Temperature Sensor
void isRHT03(){
// Call rht.update() to get new humidity and temperature values from the sensor.
int updateRet = rht.update();
// The humidity(), tempC(), and tempF() functions can be called -- after
// a successful update() -- to get the last humidity and temperature value
latestHumidity = rht.humidity();
latestTempC = rht.tempC();
latestTempF = rht.tempF();
}
getRTCDS3231.ino
// DS3231 Precision RTC
void setupRTC() {
// DS3231 Precision RTC
RTC.begin();
if (! RTC.begin()) {
while (1);
}
DateTime now = RTC.now();
if (RTC.lostPower()) {
// Following line sets the RTC to the date & time this sketch was compiled
RTC.adjust(DateTime(F(__DATE__), F(__TIME__)));
}
}
// timeRTC
void timeRTC() {
// DS3231 Precision RTC
sDate = "";
sTime = "";
DateTime now = RTC.now();
// sData
sDate += String(now.year(), DEC);
sDate += "/";
sDate += String(now.month(), DEC);
sDate += "/";
sDate += String(now.day(), DEC);
// sTime
sTime += String(now.hour(), DEC);
sTime += ":";
sTime += String(now.minute(), DEC);
sTime += ":";
sTime += String(now.second(), DEC);
}
setWiFi.ino
// WiFi
void setupWiFi()
{
// WiFi mode WIFI_AP
WiFi.mode(WIFI_AP);
// Append the last two bytes of the MAC (HEX'd) to "Thing-":
uint8_t mac[WL_MAC_ADDR_LENGTH];
WiFi.softAPmacAddress(mac);
String macID = String(mac[WL_MAC_ADDR_LENGTH - 2], HEX) +
String(mac[WL_MAC_ADDR_LENGTH - 1], HEX);
macID.toUpperCase();
String AP_NameString = "ESP8266 Thing " + macID;
char AP_NameChar[AP_NameString.length() + 1];
memset(AP_NameChar, 0, AP_NameString.length() + 1);
for (int i=0; i<AP_NameString.length(); i++)
AP_NameChar[i] = AP_NameString.charAt(i);
WiFi.softAP(AP_NameChar, WiFiAPPSK);
}
// init Hardware
void initHardware()
{
// Serial
Serial.begin(115200);
// LED Green
pinMode(DIGITAL_PIN, INPUT_PULLUP);
pinMode(LED_PIN, OUTPUT);
digitalWrite(LED_PIN, LOW);
// RHT03 Humidity and Temperature Sensor
// Call rht.begin() to initialize the sensor and our data pin
rht.begin(RHT03_DATA_PIN);
// DS3231 Precision RTC
setupRTC();
}
setup.ino
// Setup
void setup()
{
// Hardware
initHardware();
// WiFi
setupWiFi();
server.begin();
}
Don Luc
Project #10: ESP8266 Thing – Web Server – Mk03
AP Web Server
Not only can the ESP8266 connect to a WiFi network and interact with the Internet, but it can also set up a network of its own, allowing other devices to connect directly to it. This example demonstrates how to turn the ESP8266 into an access point (AP), and serve up web pages to any connected client.
After uploading this sketch, find another device that you can connect to a WiFi network – phone, laptop, etc. Look for a network called “Thing-XXXX”, where XXXX is the last 2 bytes of the Thing’s MAC address.
WiFi => Yes
ESP8266 Thing XXXX
He sketch sets the network’s password to “donlucmk01”.
After connecting to your Thing’s AP network, load up a browser and point it to 192.168.4.1/read. The Thing should serve up a web page showing you its ADC and digital pin 12 readings:
Analog Pin = XXX
Digital Pin: XXX
Humidity and Temperature
Humidity: XX.XX%
Celsius: XX.XX*C
Fahrenheit: XX.XX*F
LED Green
After that, give 192.168.4.1/led/0 (No) and 192.168.4.1/led/1 (Yes) a try, and keep an eye on the Thing’s green LED while you do.
RHT03 Humidity and Temperature Sensor
The RHT03 is a low cost humidity and temperature sensor with a single wire digital interface. The sensor is calibrated and doesn’t require extra components so you can get right to measuring relative humidity and temperature.
DonLuc1901Mk02
1 x SparkFun ESP8266 Thing
1 x SparkFun FTDI Basic Breakout – 3.3V
1 x RHT03 Humidity and Temperature Sensor
3 x Jumper Wires 6″ M/M
1 x Full-Size Breadboard
1 x SparkFun Cerberus USB Cable
SparkFun ESP8266 Thing
LG1 – Digital 5
RHT – Digital 4
GND – GND
VIN – +3.3V
DonLuc1901Mk02p.ino
// ***** Don Luc Electronics *****
// Software Version Information
// Project #10: SparkFun ESP8266 Thing – AP Web Server - Mk02
// 01-02
// DonLuc1901Mk01p.ino 01-02
// SparkFun ESP8266 Thing
// AP Web Server
// RHT03 Humidity and Temperature Sensor
// Include Library Code
#include <ESP8266WiFi.h>
#include <SparkFun_RHT03.h>
// WiFi Definitions
const char WiFiAPPSK[] = "donlucmk01";
// Pin Definitions
const int LED_PIN = 5; // Thing's onboard, green LED
const int ANALOG_PIN = A0; // The only analog pin on the Thing
const int DIGITAL_PIN = 12; // Digital pin to be read
// WiFi
WiFiServer server(80);
// RHT Humidity and Temperature Sensor
const int RHT03_DATA_PIN = 4; // RHT03 data pin Digital 4
RHT03 rht; // This creates a RTH03 object, which we'll use to interact with the sensor
float latestHumidity;
float latestTempC;
float latestTempF;
void loop()
{
// RHT03 Humidity and Temperature Sensor
isRHT03();
// Check if a client has connected
WiFiClient client = server.available();
if (!client) {
return;
}
// Read the first line of the request
String req = client.readStringUntil('\r');
Serial.println(req);
client.flush();
// Match the request
int val = -1; // We'll use 'val' to keep track of both the request type (read/set) and value if set.
if (req.indexOf("/led/0") != -1)
val = 0; // Will write LED low
else if (req.indexOf("/led/1") != -1)
val = 1; // Will write LED high
else if (req.indexOf("/read") != -1)
val = -2; // Will print pin reads
// Otherwise request will be invalid. We'll say as much in HTML
// Set GPIO5 according to the request
if (val >= 0)
digitalWrite(LED_PIN, val);
client.flush();
// Prepare the response. Start with the common header:
String s = "HTTP/1.1 200 OK\r\n";
s += "Content-Type: text/html\r\n\r\n";
s += "<!DOCTYPE HTML>\r\n<html>\r\n";
// If we're setting the LED, print out a message saying we did
if (val >= 0)
{
s += "LED is now ";
s += (val)?"on":"off";
}
else if (val == -2)
{ // If we're reading pins, print out those values:
s += "Analog Pin = ";
s += String(analogRead(ANALOG_PIN));
s += "<br>"; // Go to the next line.
s += "Digital Pin 12 = ";
s += String(digitalRead(DIGITAL_PIN));
s += "<br>"; // Go to the next line.
s += "Humidity and Temperature";
s += "<br>"; // Go to the next line.
s += "Humidity : ";
s += String(latestHumidity); // Humidity
s += "%";
s += "<br>"; // Go to the next line.
s += "Celsius: ";
s += String(latestTempC); // Temperature *C
s += "*C";
s += "<br>"; // Go to the next line.
s += "Fahrenheit: ";
s += String(latestTempF); // Temperature *F
s += "*F";
}
else
{
s += "Invalid Request.<br> Try /led/1, /led/0, or /read.";
}
s += "</html>\n";
// Send the response to the client
client.print(s);
delay(1);
Serial.println("Client disonnected");
// The client will actually be disconnected when the function returns and 'client' object is detroyed
}
getRHT.ino
// RHT03 Humidity and Temperature Sensor
void isRHT03(){
// Call rht.update() to get new humidity and temperature values from the sensor.
int updateRet = rht.update();
// The humidity(), tempC(), and tempF() functions can be called -- after
// a successful update() -- to get the last humidity and temperature value
latestHumidity = rht.humidity();
latestTempC = rht.tempC();
latestTempF = rht.tempF();
}
setWiFi.ino
// WiFi
void setupWiFi()
{
// WiFi mode WIFI_AP
WiFi.mode(WIFI_AP);
// Append the last two bytes of the MAC (HEX'd) to "Thing-":
uint8_t mac[WL_MAC_ADDR_LENGTH];
WiFi.softAPmacAddress(mac);
String macID = String(mac[WL_MAC_ADDR_LENGTH - 2], HEX) +
String(mac[WL_MAC_ADDR_LENGTH - 1], HEX);
macID.toUpperCase();
String AP_NameString = "ESP8266 Thing " + macID;
char AP_NameChar[AP_NameString.length() + 1];
memset(AP_NameChar, 0, AP_NameString.length() + 1);
for (int i=0; i<AP_NameString.length(); i++)
AP_NameChar[i] = AP_NameString.charAt(i);
WiFi.softAP(AP_NameChar, WiFiAPPSK);
}
// init Hardware
void initHardware()
{
// Serial
Serial.begin(115200);
// LED Green
pinMode(DIGITAL_PIN, INPUT_PULLUP);
pinMode(LED_PIN, OUTPUT);
digitalWrite(LED_PIN, LOW);
// RHT03 Humidity and Temperature Sensor
// Call rht.begin() to initialize the sensor and our data pin
rht.begin(RHT03_DATA_PIN);
}
setup.ino
// Setup
void setup()
{
// Hardware
initHardware();
// WiFi
setupWiFi();
server.begin();
}
Don Luc
Project #10: ESP8266 Thing – Blink – Mk02
Soldering
Plated through-hole soldering (PTH), flux-core solder alloys commonly used for electrical soldering are 60/40 Sn-Pb used principally in electrical/electronic work and TENMA soldering station temperature controlled digital.
Hardware Assembly
We’re getting ahead of ourselves. To connect the FTDI programmer to your Thing you’ll need to solder something to the Thing. What, exactly, you solder to the board depends both on how you’ll use it in your project, and how you’ll interface it with the programmer. When it comes to selecting a header (or wire) to solder, there are a variety of options. We’ve tried a lot of them with the Thing:
Or you can mix and match headers to best fit your needs. Right-angle male headers may help to interface between the FTDI and the Thing. Straight male headers are a good choice for low-profile connections. Straight female headers may help with connecting to I2C sensors. And, of course, wire can be soldered to any of the pins that have a long way to connect to something.
10 pin – Break Away Headers – Straight
4 pin – Break Away Headers – Straight
6 pin – Break Away Male Headers – Right Angle
Once you’ve soldered up at least the programming port, you’re ready to load some code onto the Thing.
Programming the Thing
The ESP8266 has a built-in serial bootloader, which allows for easy programming and re-programming. You don’t need a specialized, expensive programmer – just a simple, USB-to-Serial converter. The FTDI Basic’s 6-pin header matches up exactly to the Thing’s 6-pin serial port header. To set up for programming, simply connect the FTDI directly to this port – take care to match up the DTR and GND pins.
Blink
Let’s blink some LEDs and IoT (Internet our Thing). To verify that everything works Blink: toggle pin 5, which is attached to the onboard LED Green, toggle pin 4 which is LED Green.
DonLuc1901Mk01
1 x SparkFun ESP8266 Thing
1 x SparkFun FTDI Basic Breakout – 3.3V
1 x LED Green
1 x 100 Ohm
4 x Jumper Wires 3″ M/M
1 x Full-Size Breadboard
1 x USB Cable A to Mini-B
SparkFun ESP8266 Thing
LG1 – Digital 5
LG2 – Digital 4
GND – GND
VIN – +3.3V
DonLuc1901Mk01p.ino
// ***** Don Luc Electronics *****
// Software Version Information
// Project #10: SparkFun ESP8266 Thing – Blink - Mk02
// 01-01
// DonLuc1901Mk01p.ino 01-01
// SparkFun ESP8266 Thing
// Blink
// Include Library Code
#define ESP8266_LED 5 // LED Green
int iLEDGreen = 4; // LED Green
void loop()
{
// ESP8266_LED, iLEDGreen
digitalWrite(ESP8266_LED, LOW);
digitalWrite(iLEDGreen, LOW);
delay(2000);
digitalWrite(ESP8266_LED, HIGH);
delay(2000);
digitalWrite(ESP8266_LED, LOW);
delay(2000);
digitalWrite(iLEDGreen, HIGH);
delay(2000);
}
setup.ino
// Setup
void setup()
{
// LED
pinMode(ESP8266_LED, OUTPUT); // ESP8266_LED Green
pinMode(iLEDGreen, OUTPUT); // LED Green
}
Don Luc
Project #10: SparkFun ESP8266 Thing – Mk01
Description
The SparkFun ESP8266 Thing is a breakout and development board for the ESP8266 WiFi SoC – a leading platform for Internet of Things (IoT) or WiFi-related projects. The Thing is low-cost and easy to use, and Arduino IDE integration can be achieved in just a few steps. We’ve made the ESP8266 easy to use by breaking out all of the module’s pins, adding a LiPo charger, power supply, and all of the other supporting circuitry it requires.
Why the name? We lovingly call it the “Thing” due to it being the perfect foundation for your Internet of Things project. The Thing does everything from turning on an LED to posting data with datastream, and can be programmed just like any microcontroller. You can even program the Thing through the Arduino IDE by installing the ESP8266 Arduino addon.
The SparkFun ESP8266 Thing is a relatively simple board. The pins are broken out to two parallel, breadboard-compatible rows. USB and LiPo connectors at the top of the board provide power – controlled by the nearby ON/OFF switch. LEDs towards the inside of the board indicate power, charge, and status of the IC. The ESP8266’s maximum voltage is 3.6V, so the Thing has an onboard 3.3V regulator to deliver a safe, consistent voltage to the IC. That means the ESP8266’s I/O pins also run at 3.3V, you’ll need to level shift any 5V signals running into the IC. A 3.3V FTDI Basic is required to program the SparkFun ESP8266 Thing, but other serial converters with 3.3V I/O levels should work just fine as well. The converter does need a DTR line in addition to the RX and TX pins.
Features
- All module pins broken out
- On-board LiPo charger/power supply
- 802.11 b/g/n
- Wi-Fi Direct (P2P), soft-AP
- Integrated TCP/IP protocol stack
- Integrated TR switch, balun, LNA, power amplifier and matching network
- Integrated PLLs, regulators, DCXO and power management units
- Integrated low power 32-bit CPU could be used as application processor
- +19.5dBm output power in 802.11b mode
Don Luc