Welcome to another Arduino Tutorial! Today we are going to learn how to use Bluetooth to exchange data between two Arduino boards! As a demonstration project, we are going to build a simple weather station. There is a lot to cover so let’s get started!
Arduino Two-Way Bluetooth Communication Tutorial – [Link]
I use feature from article Another adjusting clock with alarm & thermometer using DS3231 on 1.8″ ST7735 display and change reading internal temperature of DS3231 with DHT22 sensor (AM2302), but you can use a cheaper and not very precise DHT11 sensor.
By using educ8stv_rtctft160_alarm_dht.ino or much better educ8stv_rtctft160_alarm_eeprom_dht.ino sketch, on display you can see: name of day, date, hour clock, hour alarm, temperature and humidity
Adjusting clock with alarm, hygrometer & thermometer on 1.8″ ST7735 display – [Link]
Lucky Resistor has build a PWM fan controller using Arduino and DHT22 sesnsors.
The fan controller described on this project page, controls one or more PWM controlled 12V PC fans. It uses the input from two precise DHT22 based temperature sensors. The MCU is an Arduino Uno, which is powered using a 12V power source. On top of the Arduino Uno, there is the Adafruit data logger shield — and on top of that is an Adafruit LCD shield. The software is a simple, custom written PID controller.
Programmable thermostats are cool things. They let you set the room temperature according to your schedule and will automatically make those adjustments for you. If you use them the way they’re intended to, they could be a great way to save on home energy costs. They work perfectly for people with fixed daily schedules. You can set one temperature during the time you are at home and to another when you are away. But what if your everyday routine is not the same? Then you have to manually adjust the temperature every time you are in and out. Ed Van Every was facing the same issue and he came up with a nice DIY solution for this. He wanted his place to be heated to 70ºF when it is occupied, and to 55ºF when it is not. So he made his own dual set point thermostat which allows him to implement his “working temp” with a single hit of a push button and his “away temp” with another push button.
Like most other DIY thermostats, Ed also used an Arduino board as the main brain of the thermostat and DHT22 for sensing ambient temperature and humidity. For controlling the heater, an electromechanical relay breakout board was used. A 16×2 character LCD displays the temperature setting that is currently active, its set-point value, the actual room temperature and humidity. In the event when the heater is turned on, an asterisk symbol * is displayed in the lower middle of the display indicating that the relay circuit is closed. The room temperature and humidity are refreshed every 2½ seconds and the LCD backlight automatically turns on for 60 seconds when a button is pressed on the thermostat. Ed also 3D printed a nice enclosure for his thermostat to give it a more professional look.
This project describes a DIY wireless temperature and humidity monitor for kids’ or infant’s room using the Arduino platform, and inexpensive and easily available ASK transmitter/receiver modules. On the transmitting end, an Arduino nano senses the ambient room temperature and humidity using the DHT22 sensor and transmits the data to a receiving end Arduino over a 433 MHz ASK RF link. The receiving side Arduino decodes the received bytes and displays the information on a LCD screen. The indoor range of the RF transmission is about 100 ft, which is mostly sufficient for a decent size house.
Wireless temperature and humidity monitor for baby’s room – [Link]
educ8s.tv tests the new Raspberry Pi 3 board, by building a simple but useful project.
A few months back, the Raspberry Pi 3 board was released. It is a great new board because it now offers WiFi and Bluetooth connectivity out of the box! It uses a quad core processor which operates at 1.2Ghz and it has 1GB of RAM available. From the benchmarks I have seen, this board is at least 3 times faster than the original Raspberry Pi. It can run Linux and offers 40 GPIO pins for our projects. The impressive thing is its price. It costs around 40$ and Gearbest.com was kind enough to send me a sample unit in order to test it and build projects with it.
Touch Weather Station using a DHT22 Sensor and a Raspberry Pi 3 with TKInter – [Link]
Jordan Kreindler shows us how to build a Battery Saving LCD display that is a able to show Time, Date, Humidity and temperature using DHT22, RTC3231 and Arduino.
The power saving mode here is what sets this Instructable apart from other examples showing day of the week, month, day of the month, time, humidity, and temperature. It is this capability that allows this project to be run from a battery, without the requirement for a “wall wart”.
Calendar- Time – Humidity and Temperature Arduino LCD display – [Link]
DHT11 is a common humidity & temperature sensor. This sensor has a single wire serial interface with special timing diagram for the single wire interface.
When the MCU sends a start signal, DHT11 sends a response signal followed by the humidity reading and then the temperature reading.
To know more details about the operation of DHT11, a project on hackster.io made by Jan Zumwalt, demonstrates how you can connect DHT11 with Olimex Pic32 Pinguino Micro.
Jan said that he tested the code with a DHT11, and should work with DHT22. DHT22 have a larger ranges for humidity and temperature readings.