Bajdi blogged about his Arduino pro mini undershield:
I’ve designed another PCB This time it’s a simple undershield for the Arduino pro mini. I received the PCB’s from Electrodragon (12$ for 10PCB’s) last week. The PCB has a schottky diode and a 5V linear regulator, I’m using an LM2940 5V regulator. For the rest there are just 2 rows of female headers to plug the pro mini in and 3 rows of male pins on each side.
The reason I’ve had this PCB made is that pro mini’s are dirt cheap these days, you can find them on Ebay or Chinese shops for mess then 4$. That makes them the cheapest Arduino on the internet. It’s cheaper and easier to buy a pro mini and integrate it in to your own project then to design your own PCB with an ATmega328.
Arduino pro mini undershield – [Link]
ASCAS @ instructables.com writes:
Control your Arduino with voice commands using an Android smartphone! Before we make a voice activated home automation system, we must first learn the basic principles of the experiment. This guide will let you command the Arduino using your Android smartphone and a HC-05 Bluetooth module.
The designer of the app did not include a sample code. I looked for alternatives in Google’s PlayStore but none was as good as the app that I’ve found. Luckily, I was able to figure it out although it took me a while to program it. Sorry IOS users, this app isn’t available in Apple’s app store :/
Voice Activated Arduino (Bluetooth + Android) – [Link]
Digispark Pro – The tiny Arduino IDE ready, usb and mobile dev board and ecosystem – cheap enough to leave in any project! Wi-fi, BLE, and 25+ shields!
Serial over USB debugging, USB programmable, 14 i/o, SPI, I2C, UART, USB Device Emulation, Mobile Development Ready, Optional BT, BLE, Mesh, and Wi-Fi.
The super small, dirt cheap, always open source, Arduino compatible, USB (and Mobile and Wireless!) development (and production) platform, and follow-up to the original Digispark.
Easier to use, more pins, more program space, more features, more reliable – supporting the entire existing Digispark ecosystem of 25+ shields and adding Wi-Fi, Bluetooth, BLE shields and more! Ready for all your projects – including mobile hardware development! All still super affordable!
The Digispark Pro Ecosystem is the cheapest, Arduino compatible development platform for Mobile and Wireless hardware development.
Digispark Pro – tiny, Arduino ready, mobile & usb dev board! – [Link]
by Kalle Hyvönen:
I bought a small aquarium (54l) as an impulse buy and I needed some lights for it, so naturally I wanted to use LEDs. I also needed a timer for the lights. I also wanted the lights to fade in and out when they were going on or off as a cool effect.
I ordered four Cree XP-G R5 LEDs (cool white, apparently too warm of a light will cause algae growth) and a one amp (switching) constant current supply (with PWM support) from LED-tech.de. I had some Maxim DS3234 real-time clocks with a serial bus (SPI) which looked easy to implement so I decided to use one. I also had one spare Arduino board so that was going to be my microcontroller of choice. I used a laptop power supply as the power source.
LED aquarium lighting with an Arduino based PWM timer – [Link]
Raj @ embedded-lab.com writes:
A group of students at Indiana university has built an Arduino-based distance measuring tool as their class project. It is a handheld device that measures the distance between any two points using the latitude and longitude coordinates (received from GPS satellite) of the points. It provides distance output in Yards and is useful for sports applications, such as in golfing to compute the distance between where a ball is hit and where it ends up.
Distance meter using GPS and Arduino – [Link]
Here’s Oscar Liang another Arduino GPS project, he writes:
Garlow stands for GPS Arduino Rechargeable Logger OLED Watch. The device gives GPS information which is logged on SD card and shown on a OLED display. It can be carried as a watch or simply used as a GPS data logger. The whole system is based on Arduino Nano, with a Lipo power management module which enables USB battery recharge.
A small GPS Arduino watch/clock – [Link]
Heinz Pieren writes:
ArdaSol is the project name for my solar energy and Arduino based monitoring system. This description shows how the system is built and how it works. The energy production of a photovoltaic plant is monitored and also the consumption or feeding to grid of the energy. Data acquisition during a solar day and publishing on the internet is also a function of this system.
ArdaSol – Photovoltaic Energy Monitoring System – [Link]
bbustin @ instructables.com writes:
Not everyone lives somewhere with central air, or is willing to pay for a Nest or similar “smart” thermostat. The Climaduino is a DIY Arduino-based thermostat designed to control a wall unit A/C. I incorporated both temperature and humidity sensors in order to optimize comfort and reduce energy usage. I then developed a Raspberry Pi-based web interface to control the Climaduino from my phone.
This is still a work in progress, but is definitely functional. I am posting this instructable so others can both build their own smart thermostats, and hopefully build on this project with their Climaduino improvements.
Introducing Climaduino – The Arduino-Based Thermostat You Control From Your Phone! – [Link]
Mizchief100 @ instructables.com wanted a way to control with dorm air conditioner so he build an Arduino thermostat that controls the control knob using a servo motor:
I am currently living in a college dorm. Like most dorms it’s about the size of a tissue box but less comforting. Fortunately, my room has a heater/AC with four positions: low, medium, high, and off. Unfortunately in winter an hour on the low setting makes the room a stifling 80 degrees and when turned off it drops quickly to 60 degrees. My solution uses an arduino, temperature sensor, and motor to automatically turn the heater on/off to keep the room within a desired temperature range. Not only is this more comfortable but it dramatically reduces the time the heater is used, saving lots of energy. (Also note that the motor is only driven to switch the setting and then turned off so no holding energy is wasted.)
Arduino Thermostat (Mechanical) – [Link]
This instructable will show you how to build a portable Touch Screen Oscilloscope for less than 40 U$! johnag @ instructables.com writes:
The oscilloscope is one of the most powerful electronic instruments that is available to electronics hobbyist, experimenters, and engineers. It is mainly used to measue time-varying signals. Any time you have a signal that varies with time( slowly, quickly, and /or periodically ) you can use an oscilloscope to measure it , visualize it, and to find any unexpected features in it.
Make an Oscilloscope using the SainSmart Mega2560 – [Link]