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Wifi controlled smart light bulbs can now be purchased from less than USD 10. However, those can often only be used by a specific application provided by the vendor and can involve exchanging data with a third party server. I wanted a solution to use my own software while benefiting from the cheap hardware so I replaced the wifi module of a a cheap Wifi light bulb my own electronics.

Over the years, I have built multiple IoT devices ranging from AC controllers to ceiling lights. Usually, I would control those devices using my smartphone or computer but sometimes a physical button can be more convenient. Thus, I designed this simple IoT button which publishes MQTT messages when pressed.

Although probably in the decline, infrared is a common way to remotely control household appliances such as air conditioners or TVs. Being able to turn on an AC unit without leaving the sofa is definitely comfortable, but sometimes it would be even better to be able to do it before even getting home. In order to control those various appliances, I designed a simple WiFi controlled IR emitter.

I am not much of a cook so salads are usually one of my favorite options for a healthy meal. So, just like for everything else, I started wondering if I could make my own. However, I don't have access to a garden so I started looking into solutions to grow vegetables indoors. I settled for hydroponics, which seemed to provide a good balance between yield and operational hassle. Specifically, I went for a Deep Water Culture type of hydroponic system as it is usually considered easy for beginners to setup.

Global warming and the COVID-19 pandemic are some the many challenges humanity is having to face. However, I somehow decided that the problem I was going to solve is having to take my keys out of my pocket whenever I lock or unlock my front door.

With the COVID-19 pandemic, many of us cannot participate in family gatherings or other similar events in person. Instead, some opt for video-call applications like zoom, but then get constrained to the field of view of camera of the device used for the call.

Earlier this year, a friend of mine was organizing an event to promote eco-friendly behaviors. She wanted someone to talk about our relationship with energy and asked me to give a presentation on the topic, which I agreed to. I wanted the presentation to be entertaining so I designed a set of hardware demonstrations aimed at explaining physical concepts related to energy.

A company I worked for had a coffee machine for which employees could purchase coffee. However, the payment was done by putting coins in a jar. Not only did this present the obvious risk of theft, this system was also impractical for people not carrying spare change at all time. I decided to solve this issue by designing this cashless payment system.

Air conditioners consume a fair amount of electricity. As such, forgetting to turn one off before leaving one's home can result in an expensive electricity bill. This is a Wi-Fi enabled controller for air condtioners, which can turn the unit on or off according to MQTT messages. It is built around an Wemos D1 mini and interfaces with the AC using an IR LED.

I got my hands on a 600W 12V inverter so I decided to experiment with generating my own electricity.