This project builds a basic electronic door lock with the Arduino UNO R4 WiFi. A touch sensor detects contact, a relay controls a solenoid lock, and an OLED display shows the system status. The principle is simple: touch the sensor, the door unlocks for 5 seconds, then locks itself again. It is a starting point for customizable smart locking systems.

The central board is the Arduino UNO R4 WiFi, which manages the whole flow. The touch sensor sends a signal to the board, which activates the relay to power the lock. The 128×64 pixel OLED display shows the startup, locked, and unlocked screens. The system uses a relay module to separate the control circuit from the power circuit, so the solenoid lock operates safely.

The circuit and components of the lock

Assembly requires few components: the Arduino board, the touch sensor, the OLED display, the relay module, and a solenoid lock. Everything connects on a breadboard with jumper wires. The relay is essential because the lock runs at 12 VDC, while the Arduino operates at 5 V. Without the relay, the lock’s current would damage the board.

The OLED display connects via I2C, using the SSD1306 and Adafruit_GFX libraries. The 128×64 pixel resolution is enough to show the system status with clear characters. The touch sensor connects to a digital pin: when it detects a touch, it sends a high signal to the Arduino. The response is immediate, and the relay trips right away.

The firmware and unlock time

The code is written in the Arduino IDE and uses the SSD1306, Adafruit_GFX, and Adafruit_SSD1306 libraries. The sketch reads the touch sensor state and, when it detects a touch, activates the relay. The display shows the unlock screen for 5 seconds, then the system locks the door again. The unlock time is fixed at 5 seconds, but it can be changed in the code.

The operation is cyclic: startup, waiting, unlock, relock. The OLED display updates the status in real time, so you always know whether the door is locked or unlocked. The project demonstrates the principle of a basic electronic lock, and the maker’s website collects the details for replicating it. It is a simple but complete system.

For assembly you also need a universal acrylic support to keep the Arduino and breadboard tidy. 15 cm male-to-female jumper wires help connect the modules without soldering. The project can be expanded with a numeric keypad, an RFID reader, or a Wi-Fi module for remote control.

In short, this project is an excellent base for anyone who wants to understand how an electronic lock works. The components are few, the code is essential, and the result is functional. With the Arduino UNO R4 WiFi you also have the option to add connectivity in the future, turning the prototype into a real smart lock.

Source: https://srituhobby.com/how-to-make-a-solenoid-door-lock-system-using-a-touch-sensor/

The post Electronic door lock with Arduino UNO R4 WiFi and touch sensor appeared first on Open Electronics.

Home automation systems are all well and good, so long as the person who built it all is around to drive it. Let’s face it, they’re quite often a complex web of interconnected systems, all tied to the specifics of one’s home — and someone less familiar with it all could get a little irritated if, on a chilly day, the interface to the boiler is via a Python script, and something won’t work. Just saying. Home Buttons by [Matej Planinšek] over on Hackaday.IO is a nicely polished project, which aims to take some of the hackiness out of such automation by providing a sleek front end to those automation routines, enabling anyone to rock on over and set one in action without hassle.

The PCB is based around the ESP32-S2-mini which deals with WiFi connectivity and integration with Home Assistant using the usual MQTT protocol. We expect integration with other flavors of home automation would not be difficult to achieve. The center of the unit holds a simple E-Ink display, for that low-standby power. Specifically, the unit chosen is a Good Display GDEY029T94 2.9″ which this scribe can confirm is easy to interface and pretty cheap to purchase from the usual Chinese online vendors. This was matched up with six clicky Alps SKRB-series low-profile tact switches, which sit on either side of the display, and corresponds to a flexure-type affair on the 3D printed front casing. Neat and simple.

The PCB design was provided in Altium format, which you can find on the project GitHub page. This shows a straightforward design, with a few nice little details here and there. The internally mounted 186550 cell is reportedly good for at least a year of operation, but when time, it can be charged via USB. A Xysemi XB8608AF (PDF) protection chip provides appropriate limiting for the 186550 cell, shielding it from the perils of overcharging, discharging, and whatnot. Not that that is likely in this current setup. A Sensiron SHTC3 humidity and temperature sensor is also in there, hanging off the I2C bus, which makes sense for this application.

Home Automation hacks are plenty on these pages, like this scroll-wheel interface, for instance. If all this stuff is looking quite overbearingly complicated to get into, how about starting with a Pico W?

At Hackaday, we celebrate all kinds of projects, but we’ll have to admit that the polished and professional-looking builds tend to catch our eye a lot more than perhaps they should. There’s plenty of love to be had for the rougher builds, though, of which this quick-and-dirty home automation system is a perfect example.

Before anyone rushes to state the obvious with, “Should have used some relays,” consider that [MAKE_IT_WITH_ME]’s stated goal was to get the basics of a home automation system built with pretty much nothing but what can be found in one of those Arduino starter kits. And further, consider that landlords might not look kindly on tenants who wire a bunch of SSRs or Sonoff switches into the walls of their building. So this minimalist build is perfect for certain use cases. Its interface to the building’s electrical system is 100% mechanical, via a servo that travels along the bank of switches on a stepper-driven leadscrew. The servo has a modified horn to properly flick the rocker-style switches, and although changing from switch to switch is a bit slow, it works surprisingly well. The video below shows it in action.

While we can see it possibly working as-is for Decora-style switches that are seen in some markets, we’d think some mods would be in order for the more standard toggle-style switch — perhaps a finger extending out from the horn, along with a second servo to tilt the whole assembly away from the wall to allow it to clear the switch bats.

In many parts of the world leaving open a door or window is a good way to get a house full of bugs. Remembering to close doors behind them can be surprisingly hard for members of the human race, so the [DuctTape Mechanic] used the components from a car’s electric window to automate his sliding screen door.

After the excess pieces were cut of the rail, the motor and rail were mounted on top of the door frame. A long bolt is attached to the moving plate on the rail, which pushes on the pack of the door to close it. After closing, the mechanism returns to its open position, allowing the door to be opened by hand. The motor is controlled by an Arduino running a very simple sketch, which senses if the door is closed with a microswitch and starts a 10 second countdown once opened. Two relays are used to create an H-bridge circuit to drive the motor in both directions.

It doesn’t look like there is any provision to detect if it is obstructed. A simple solution could be to make the push rod spring-loaded, so it can slide over the door if there is excessive resistance. This project is successful as a proof of concept, but making the wiring neater and covering everything would be a welcome upgrade.

If you only want to let certain creatures into your house, we have no shortage of automated pet door for your hacking pleasure.

What do you do if your light switch is too far from your desk, and you’re in a rental property so you can’t put in extra wiring to install an electronic control for it? Get up and turn it on or off by hand? Of course not!

If you are [Guyfromhe], you solve this problem with a servo attached to a screw-on light switch faceplate, and you control it with a pair of Arduino/nRF24L01 combos. It’s a pretty simple arrangement, the wireless link simply takes the place of a serial cable that instructs the Arduino on the light switch to operate the servo that in turn moves the switch. The whole thing is triggered through his home automation system, which in turn responds to an Amazon Dash button on his desk. Yes, it’s complex. But turning on the light has been automated without intrusion into his landlord’s domain, and that’s all that matters.

On a more serious note, he’s put some Arduino code up on his write-up, as well as a YouTube video we’ve put below the break.

This is by no means the first such switch we’ve seen, after all we featured a nicer 3D printed servo light switch the other month, and one with a breadboarded Arduino in 2015. While we’re at it though, it would be nice to see a few designed for European switches too.

[nebulous] has a lot of problems with his kitchen cabinets. Aside from a noted lack of micro-controllers, he was especially suspicious of the dark spaces under them. Anything could be hiding there.

The core of the project is a $10 Arduino-compatible esp8266 board from digistump. The board is powered by the five volt regulator of an L298N motor driver module hooked to a power-supply. All this controls a set-of LED strips adhered to the underside of the cabinets with the traditionally bad adhesive strips with which they come standard. We can predict an hour spent bent awkwardly cursing at them, a hot-glue gun in one hand, in [nebulous]’s future. The whole set-up is housed in a SparkFun cardboard box above the microwave. You can barely tell it’s not a commercial product.

We’re not certain if we like a future where even our cabinetry has an IP address. However, this is a good weekend project that could make all our cabinetry brighter, safer, and more connected.

Take three NRF24L0+ radios, two Arduino Nanos, and a Raspberry Pi. Add a bored student and a dorm room at Rice University. What you get is the RRAD: Rice Ridiculously Automated Dorm. [Jordan Poles] built a modular system inspired by BRAD (the Berkeley Ridiculously Automated Dorm).

RRAD has three types of nodes:

• Actuation nodes – Allows external actuators like relays or solenoids
• Sensory nodes – Reports data from sensors (light, temperature, motion)
• Hub nodes – Hosts control panel, records data, provides external data interfaces

The hub also allows [Jordan] to control things with his Android phone with Tasker. He has the Arduino and Raspberry Pi code on GitHub if you want to ridiculously automate something of your own. You’d probably want to adapt it to your dorm room, house, or RV, though.

[Jordan] continues to work on the project and promises to have voice recognition and other features, soon. We cover a lot of home automation projects including some others described as ridiculous. The video below shows BRAD, the inspiration for RRAD.

Take advantage of these open source resources to set up voice control with Raspberry Pi and bark orders at your home appliances.

Read more on MAKE

The post Roomba, I Command Thee: Use Raspberry Pi for Voice Control appeared first on Make: DIY Projects, How-Tos, Electronics, Crafts and Ideas for Makers.