Sure we can have our kids back up against a wall, force them to stand up straight, and use a ruler on their head to mark their height on the wall, but what kind of hacker would we be? There isn’t a single microcontroller or any electronic component involved! The DIY-family that calls themselves [HomeMadeGarbage] stood tall and came up with a high-tech tool to measure their kid’s height.
In place of the ruler they got a small wooden box to place on the head. Under the box, at the rear end facing down, they mounted a VL53L0X laser ranging sensor. With a range of 2 meters it’s sure to work with any child. But the box has to be sat level on the child’s head, otherwise the laser will be pointing down at an angle. To handle that they put an MPU6050 6-axis motion sensor in the box along with an Arduino Nano to tie it all together. A LCD display, measurement push-button and LED are mounted outside the box on the rear facing side.
To use it, a parent sits the box on the child’s head, making sure the laser sensor isn’t blocked and can see the floor. The LCD shows the height, along with the acceleration in the x and y directions. The LED is red if the box isn’t level and green if it is. Holding the measurement button pressed puts the tool in measurement mode and when it’s level, the LED turns blue and the LCD display freezes so you can make a note of the height. You’re good for a while, depending on your child’s age. See it being used to measure a child after the break as well as an additional clip showing what the output looks like when waving a hand up and down below it.
The Brasilia Lady comes with a 300 ml brass boiler, a pump and four buttons for power, coffee, hot water and steam. A 3-way AC solenoid valve, wired directly to the buttons, selects one of the three functions, while a temperamental bimetal switch keeps the boiler roughly between almost there and way too hot.
To reduce the temperature swing, [Rhys] decided to add a PID control loop, and on the way, an OLED display, too. He designed a little shield for the Arduino Nano, that interfaces with the present hardware through solid state relays. Two thermocouples measure the temperature of the boiler and group head while a thermal cut-off fuse protects the machine from overheating in case of a malfunction.
Also, the Lady’s makeup received a complete overhaul, starting with a fresh powder coating. A sealed enclosure along with a polished top panel for the OLED display were machined from aluminum. [Rhys] also added an external water tank that is connected to the machine through shiny, custom lathed tube fittings. Before the water enters the boiler, it passes through a custom preheater, to avoid cold water from entering the boiler directly. Not only does the result look fantastic, it also offers a lot more control over the temperature and the amount of water extracted, resulting in a perfect brew every time. Enjoy [Rhys’s] video where he explains his build:
How do you earn a place in a flower festival with a handful of Arduinos and a 3D printer? By building a water curtain that draws flowers. That’s exactly what Tecnoateneu Vilablareix, a hacking community in Spain did. They built this project specifically for Temps de Flors, a popular annual gathering in Girona, Spain. More than just a flower festival, the event opens gardens and courtyards of culturally importance to the general public that are closed the rest of the year.
The water curtain uses four Arduino Nanos to control the valves, which work in pairs to draw flowers, words, and patterns. A Mega provides a wifi connection to receive commands. Over 16 continuous days worth of print time went into the 128 valves and 64 nozzles that make up the water curtain. It took the group around 24 iterations to get the valve design just right—they have to be able to shut off quickly.
There’s an eight-video playlist after the break and a special video that shows how much we love pandering. Most of the ones in the playlist are quite short and demonstrate the final version of the water curtain. Others show the valve testing. The last is a time-lapse of the group setting it up at the festival. If you’re in the area, the festival runs until May 15th.
[TVMiller] has a bone to pick with you if you let your car idle while you chat or text on your phone. He doesn’t like it, and he wants to break you of this wasteful habit – thus the idle-deterrence system he built that he seems to want on every car dashboard.
In the video below, the target of his efforts is clear – those who start the car then spend time updating Twitter or Instagram. His alarm is just an Arduino Nano that starts a timer when the car is started. Color-coded LEDs mark the time, and when the light goes red, an annoying beep starts to remind you to get on with the business of driving. The device also includes an accelerometer that resets the timer when the vehicle is in motion; the two-minute timeout should keep even the longest stop light from triggering the alarm.
[TVMiller] plans an amped-up version of the device built around an MKR1000 that will dump idle to moving ratios and other stats to the cloud. That’s a little too Big Brother for our tastes, but we can see his point about how wasteful just a few minutes of idling can be when spread over a huge population of vehicles. This hack might make a nice personal reminder to correct wasteful behavior. It could even be rolled into something that reads the acceleration and throttle position directly from the OBD port, like this Internet of Cars hack we featured a while back.
Soldering might look like a tempting and cheap alternative when building or repairing a battery pack, but the heat of the iron could damage the cell, and the resulting connection won’t be as good as a weld. Fortunately, though, a decent spot welder isn’t that tough to build, as [KaeptnBalu] shows us with his Arduino-controlled battery spot welder.
When it comes to delivering the high currents necessary for spot welding, the Arduino Nano is not necessarily the first thing that comes to mind. But the need for a precisely controlled welding pulse makes the microcontroller a natural for this build, as long as the current handling is outsourced. In [KaeptnBalu]’s build, he lets an array of beefy MOSFETs on a separate PCB handle the welding current. The high-current wiring is particularly interesting – heavy gauge stranded wire is split in half, formed into a U, tinned, and each leg gets soldered to the MOSFET board. Welding tips are simply solid copper wire, and the whole thing is powered by a car battery, or maybe two if the job needs extra amps. The video below shows the high-quality welds the rig can produce.
Spot welders are a favorite on Hackaday, and we’ve seen both simple and complicated builds. This build hits the sweet spot of complexity and functionality, and having one on hand would open up a lot of battery-hacking possibilities.
Just in time for Valentine’s Day, here’s a project out of the LVL1 hackerspace in Louisville that should warm the heart of that special someone in your life. Behold the Magic 8 of Hearts.
The metaphors are somewhat mixed here, what with the heart-shaped box, the mysterious black window of a Magic 8-ball, and the cheesy once-a-year sayings like those printed on Sweethearts candies. [JAC_101] began surgery by punching a hole in the plastic heart for an OLED display. The white on black display evokes the Magic 8-Ball look, although adding a blue filter would have nailed it. A 3-axis accelerometer detects shaking motion and an Arduino Nano selects a message to display. Some white LEDs light up the enclosure and add a little pizzazz. As a bonus, the whole thing is inductively charged – no extra holes needed in this heart.
Old Mini and Mainframe computers often had huge banks of diagnostic lights to indicate the status of address, data and control buses or other functions. When the lights blinked, the computer was busy at work. When they stopped in a particular pattern, engineers could try and figure out what went wrong by decoding the status of the lights.
[Folkert van Heusden] has an old MSX-based Philips VG-8020 computer and decided to add his own set of BlinkenLights to his system. The VG-8020 was a first generation MSX released in 1983 and featured a Zilog Z80A microprocessor clocked at 3.56 MHz, 64KB of RAM, 16KB of VRAM, and two cartridge slots.
The cartridge slots of the MSX are connected to the address and data buses in addition to many of the control signals, so it seemed logical to tap in to those signals. Not wanting to play around with a whole bunch of transistors, he opted to use an Arduino Nano to connect to his computer and drive the LEDs. In hindsight, this seemed like a wise decision as it allowed him to do some processing on the incoming data before driving the LEDs.
Instead of creating a new PCB, he cut open one of his beloved game cartridges. A switch was added to the slot select control pin (SLTSL) and eight wires soldered directly to the data bus. These were hooked up as inputs to the Arduino. A bank of eight LEDs with limiting resistors were connected to outputs on the Arduino. A quick test confirmed it all worked, including the switch to enable / disable the cartridge. He had to experiment with the code a bit as the LEDs were initially blinking too fast.
A couple of months later, he upgraded his BlinkenLight display to include the 16 bit address, 8 bit data and 8 lines for control signals. To do this, he used two MCP23017 – I2C 16 input/output port expander chips. For the LEDs, he installed a bank of four NeoPixel LED bars. A Pro-Mini takes care of the processing, and a custom PCB in the cartridge format houses all of it neatly. Check out the two videos below showing the BlinkenLights in action.