Articles

Mosquitto can usually be installed on an Ubuntu server fairly easily using the APT package manager. By Default, the broker handles unencrypted MQTT connections but it can be configured to use SSL certificates obtained, for example, using Certbot and thus enable MQTTs connections. This configuration is usually achieved by editing the Mosquitto configuration file in /etc/mosquitto so as to point to certificates obtained independently. However, when deploying Mosquitto to Kubernetes, one would prefer not to edit configuration files manually after install. Moreover, in Kubernetes, one can use Cert-manager to obtain SSL certificates. Thus, this article presents an efficient method to deploy a secure MQTTs broker in Kubernetes.

RFID is a conveninent technology for access control and authentication. In this project, I connected an RC522 RFID reader to an ESP32 in order to use it for IoT applications. Additionally, to provide feedback to the user, the ESP32 is also connected to an SSD1306 OLED display and a buzzer. I chose an ESP32 over an ESP8266 simply because of the amount of GPIOs required.

This headset enables the overlay of information on top of its user's field of view. The field of view of the user is captured by a camera and then fed to video goggles, while a MAX7456 OSD chip overlays text on the video feed.

RFID tags come in various forms and sizes, from standard plastic cards to chips that can be implanted in one's hand. I got particularly interested in RFID rings, which can be purchased online for less than USD 20$. Those are based on EM4305 chips, which require a compatible reader. Thus, I designed an IoT EM4305 reader that can exchange data over MQTT with other devices.

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.

Smartwatches can be rather expensive and tend to be known for their poor battery life. On the other hand, Xiaomi's Mi band 2 is cheap and its battery lasts for up to 20 days. However, the Mi band 2 is mainly limited to fitness tracking functions, at least without the appropriate apps.

Have you ever left your apartment and couldn't remember if you locked your front door or not? Sadly, if it is unlocked, there is not much you can do about it until you get back home. This system is an attempt to solve the problem. Simply put, it consists of attaching an actuator to the door's original locking mechanism control it with through WiFi.

GitLab provides Kubernetes integration out of the box, which means that GitLab CI/CD Pipelines can be used to deploy applications in Kubernetes easily. This guide presents how to integrate a Kubernetes cluster in a GitLab Project and follows Gitlab documentation. For this particular case, the cluster will be that of a Microk8s Kubernetes distribution.