Planet Arduino

How long can you keep an Arduino circuit running on three AA batteries? With careful design, [educ8s] built a temperature sensor that lasts well over a year on a single charge of three 2250 mAH rechargeable cells (or, at least, should last that long).

Like most long-life designs, this temperature sensor spends most of its time sleeping. The design uses a DS18B20 temperature sensor and a Nokia 5110 LCD display. It also uses a photoresistor to shut off the LCD display in the dark for further power savings.

During sleep, the device only draws 260 microamps with the display on and 70 microamps with the display off. Every two minutes, the processor wakes up and reads the temperature, drawing about 12 milliamps for a very short time.

Along with the code, [educ8s] has a spreadsheet that computes the battery life based on the different measured parameters and the battery vendor’s claimed self discharge rate.

Of course, with a bigger battery pack, you could get even more service from a charge. If you need a refresher on battery selection, we covered that not long ago. Or you can check out a ridiculously complete battery comparison site if you want to improve your battery selection.

by jazzycamel:

I work as a software developer for a biology lab where my day job consists of creating applications to deal with big data visualisation. Recently however one of my colleagues had the need to take regular temperature measurements form a range of jars of liquids over quite an extended period. The commercial available solutions to achieve this are expensive and surprisingly lacking in features. So, as a dedicated hacker and maker, I immediately stepped in an said we could make something better ourselves. So we did. And this is how.

Quick & Easy Temperature Loggers - [Link]

The Arduino and Cloud-based homebrewing controller by Martin Kennedy of TheBedroomLaboratory:

It’s just a basic site, based on this Scotch.io tutorial, which is currently plotting the temperature in my sitting room. It’s got a PHP backend (Laravel framework with RESTful API), MySQL database and an AngularJS frontend with (n3-chart/d3 for the graph). In the house, I’ve whacked together a quick breadboard circuit which comprises of an Arduino clone, a DS18B20 Temperature Sensor (with resistor for the i2c connection) and an ESP8266 module. Every minute, this wireless sensor POSTs the temperature to our REST API. This value is saved in the database and will appear in the graph whenever the page is opened. To hook it up to a fermenter, the sensor would just be placed in a thermowell in the fermenter bucket so we can see the beer temperature over time.

[via]

Brewmonitor: The Arduino-powered, cloud-based homebrewing controller - [Link]

We live in the future don’t we? Is there a reason why only rich people have touchscreen controlled showers and temperature regulated bathtubs? [Raptor_Demon] shows us how to make our very own automated bathtub for cheap, using our favorite microprocessor — the Arduino.

The system controls the filling of the tub, monitors the temperature based on a user profile — and it even adds bubbles. Why do you need this? You probably don’t — but why not, wouldn’t it be nice to press a button and have a bath drawn for you? It uses an Arduino compatible board that controls 3 relays for the water system, a DS18b20 temperature sensor on the inlet and a second wireless (434mhz) Arduino compatible board for monitoring the tub temperature and adding bubble bath using a hacked automated soap dispenser.

[Raptor_Demon] showcased his prototype at the Maker Faire NC 2013 and 2014 where it was a huge hit. He even had a full size tub going, in which he would sit in during his explanation — check it out!

[Thanks Hardik!]

Timofte Andrei wrote this instructable detailing the build of his Arduino home automation system:

For this project I’ve used:
1. An Arduino clone
2. SIM900 GSM SHIELD
3. Relay module
4. 2×16 LCD Display
5. DS18B20 temperature sensor
6. Push button
7. Some Dupont wires
8. A led module (this is optional, if you have a chinese relay module with built in LEDs)
9. Some nuts and bolts to mount everything in place
10. A wooden chopping board or other kind of wooden board for propper display of the components

[via]

Arduino GSM home automation system - [Link]

Instructables user Slomi posted this useful project on how to build a wireless indoor and outdoor thermometer using an Arduino! Via Embedded Lab.

This Arduino-based wireless thermometer uses two Arduino boards to measure indoor and outdoor temperatures. The outdoor Arduino board sends out the outdoor temperature measured by DS18B20 sensor to the indoor Arduino board using inexpensive 433MHz RF transmitter and receiver modules. The indoor Arduino board then displays the indoor and outdoor temperatures on a character LCD display.

[via]

Indoor/outdoor wireless thermometer using Arduino - [Link]

BO.Duino is an Arduino compatible board based on ATmega328 ATMEL’s mcu. This board features many peripherals usually externally connected on a breadboard or prototyping board such as sensors, SD card etc. Peripherals included are:

- A real-time clock
- AT24 series external memory chip
- MicroSD card adaptor (SPI)
- RGB LED
- A potentiometer on analog input
- Connector for DS18b20 or DHt11 series sensors

BO.Duino – ATmega328 Arduino Compatible board - [Link]