Month: January 2015

I needed a temperature node, but I didn’t have a DHT22 temp/humidity sensor!?

So I modified the example sketch for the DHT to use a DS18B20 Digital Temperature Sensor instead!

It works great!

The sensor is connected as shown here:

http://www.hobbytronics.co.uk/ds18b20-arduino

Heres the code:

 

/*

DS18B20 Digital Sensor Node Sketch for EasyIoT Server
Modified by Lewys Martin <l@lewys.eu>
See: blog.lewys.eu for details

Original Code:
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

V1.0 – first version

Created by Igor Jarc <igor.jarc1@gmail.com>
See http://iot-playground.com for details
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
version 2 as published by the Free Software Foundation.
*/
#include <Esp8266EasyIoT.h>
#include <SoftwareSerial.h>
#include <DallasTemperature.h>
#include <OneWire.h>

#define CHILD_ID_TEMP 1
#define SENSOR_DIGITAL_PIN 2
Esp8266EasyIoT esp;

SoftwareSerial serialEsp(10, 11);

OneWire oneWire(SENSOR_DIGITAL_PIN);
DallasTemperature sensors(&oneWire);

float lastTemp;

Esp8266EasyIoTMsg msgTemp(CHILD_ID_TEMP, V_TEMP);
void setup()
{
serialEsp.begin(9600);
Serial.begin(115200);

Serial.println(“EasyIoTEsp init”);
esp.begin(NULL, 3, &serialEsp, &Serial);
//esp.begin(NULL, &serialEsp);
esp.present(CHILD_ID_TEMP, S_TEMP);

sensors.begin();
}

void loop()
{
while(!esp.process());

sensors.requestTemperatures();
float temperature = (sensors.getTempCByIndex(0));
if (isnan(temperature)) {
Serial.println(“Failed reading temperature from sensor”);
}
else if (temperature != lastTemp)
{
lastTemp = temperature;
esp.send(msgTemp.set(temperature, 1));
Serial.print(“T: “);
Serial.println(temperature);
}
}

And some pictures:

I actually managed to produce something that is NEAT

and well laid out (in my opinion)

Parts:

• Arduino Nano
• ESP-01
• 5-3v Level Shifter
•  Perfboard
• Bunch of headers
• Some wire
• Soldering Iron + 0.3mm Solder
• Dremel to clean things and cut things and stuff

 

As you can see in the photos:

The board as a whole:

The board with components removed:

The underside of the board:

Cleaned edges with Dremel:

The things I have to add still:

Also, as you can see, theres a notch missing from the Arduino near the ICSP pins, I used my Dremel to grind that away (theres no traces there as far as i can tell) so that the ESP module fits so perfectly there and the whole package fits inside the dimensions of the perf board 😀

This node has been added to my EasyIoT Server as a secondary relay node for the time being, but I want to get my hands on a DHT22 to add a temp/humidity sensor to my bedroom 😀

Then I can start expanding to other rooms in the house! MWAHAHAA

Using a full size Arduino Uno modified to 3.3v, and that weird shield I built, modified to software serial pins 10 and 11, and also to add a power input of 5v that gets regulated to 3.3v on both the shield for the ESP8266, and the arduino for… itself?

It connects to a Raspberry Pi running the latest version of Raspbian and EasyIoT Server, I figured out their API without even a mention of there BEING ONE ON THEIR WEBSITE (they don’t mention it anywhere but i noticed a mention of it in the console log and figured it out)

The ESP8266 01 type connects to the main WiFi, then to the server, from then I can browse to the IP of the server and theres a beautiful interface 😀

The EasyIoT server also supports the RasPi GPIO and the MySensors stuff, so Im gonna use that for things like doors, and temp/humidity sensors

Photos will come soonish: