Know when to pee with the ATtiny! (badum tss)

This project was born from a very common problem: our office’s floor is equipped with one bathroom that can’t be seen from every desk. Ensues unnecessary back and forth when someone walks to the bathroom only to find it occupied.

The solution ? A simple bathroom monitoring system composed of two devices:

  • An emitter placed on the inside of the door of the bathroom to monitor. An infrared sensor is directed toward the lock’s knob. A piece of black tape is applied on the knob. The idea is the following: when the door is unlocked, the knob’s metallic surface is facing the sensor and reflecting a fair amount of IR light. When the door is locked, the taped part of the knob is now facing the sensor. Since the tape is black, the amount of IR light reflected decreases: we know that the door is locked. We use a radio emitter module to send the value read from the sensor to the receiver. A small Atmel microcontroller (the ATtiny85) acts as the brain of the system. The device runs on 4 AAA batteries and is put to sleep 5 seconds every time a reading is sent in order to save power.
  • The receiver is used to display the status of occupancy of the bathroom remotely. It is built around the same microcontroller as the emitter. A RF receiver picks up the readings from the emitter. Depending on the value received, we light up an RGB LED in green or red. This device runs on a wall wart since the LED is constantly turned on.

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Make an automated tea steeper- with Arduino

What we will be making

I recently got an opportunity to present my first workshop and thought that it could be interesting to share the result. It’s an introduction to Arduino for beginners during which we will be making a automated tea steeper. I chose this project because it provides a good way to introduce basics concepts of embedded programming, from lighting up an LED to dealing with an analog input, controlling a servo motor and keeping track of time, plus it was already very well documented (see the sources).
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Make a connected barometer shield for Arduino Uno – using an ESP8266


I’ve never really considered connecting my projects to WiFi since the price of the shields was so high. The HUZZAH from Adafruit will set you back $39.95. Sparkfun sells this shield for $84.95. Way to expensive.

So you might imagine my excitement when I first heard about the ESP8266 through hackaday. A WiFi module for less than $5, that sounded ideal. I started to read about it, checking out the projects that flourished around this newcomer. It seemed easy enough to use, and I was already imagining how I would start this article. Something like :

“Meet the great ESP8266, a low cost, plug&play device that will allow you to easily connect your projects to the web”.

But things did not go as planned…The first module I bought was defective, and it almost drove me nuts trying to figure out what was it that I was doing wrong. When I started to think about leaving electronics behind forever and starting a new life as a shepherd in South America, I decided that spending an additional five bucks for a new module just in case mine was broken from the start was not too much.

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How to turn an Arduino based proof of concept into a final prototype

Make an anti procrastination box – with Arduino

I had a spare segment display and wondered about what I could make out of it. Hence was born the idea of the anti-procrastination box : for those of us who are a little too close to their smartphones but need to stay away from it from productivity reasons, put the phone in the box and set the interval during which the box ought to stay locked.
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Adding bluetooth control to Clumsy the robot

Aside from the autonomous function of the robot, I wanted to be able to control it with my smartphone. The electronic guy at work pointed me toward those very cheap modules, saying that they were crap and a pain to solder but that it was alight considering the price. 3 weeks later, here they were !


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Robot 2.0

After my unsuccessful attempt at making my very own wall avoiding robot using spare parts lying around my desk, I decided to give it another try.

This time I bought a complete chassis from robotshop. It’s a two-wheeled robot, each wheel being independently powered by its own motor. An omnidirectional wheel completes the design.


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My first robot !

Because we all have to start somewhere ! So here it is, my very first attempt at building a robot. I was waiting for transistors from China because I needed those to control the motors. They arrived in the mail this morning from Shenzen and at 6$ for 10 pieces of 21 values, I’m pretty satisfied.

So what about the robot ? I’m going to try to keep it simple for a first. So a two-wheeled wall avoiding robot should be fine. I have a sonic sensor at hand for the wall avoiding part, and candle-holding plastic thingies will do the trick as for the wheels (yeah it’s a low-budget kind of robot).

The prototype worked fine was a good way to start : the speed of the motors is proportional to the distance measured by the sensor.


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Light painting : making accessories

Following last post, I’d like to present a little device I created in order to help me in my light painting adventures.

I wanted to have something that could fit in my hand, and which would help me to expand the range of patterns and colors I could for light painting. The idea is to make a sandwich with an 8×8 RGB leds neopixel matrix, an arduino uno and some batteries. Yummy.

BjcpIeICQAAShUw.jpg large

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The electro hat

We have a festival here in Montreal called the IglooFest. It’s basically thousands of people dancing their ass off some good music outside on the city’s old port.

Not very original you say ? Well, the fact that it takes place in January when the temperature is often below -20 should change your mind.

It inspired me a really quick project : mounting my 8*8 RGB neopixel matrix on the festival’s hat and adding a microphone in order to have it react to the surrounding music.


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