ArduinoMania

[Adnan.R.Khan] had a sliding door latch plus an Arduino, and hacked together this cool but simple app controlled door lock.

Mechanically the lock consists of a Solarbotics GM3 motor, some Meccano, and a servo arm. A string is tied between two pulleys and looped around the slide of a barrel latch. When the motor moves back and forth it’s enough to slide the lock in and out. Electronically an Arduino and a Bluetooth module provide the electronics. The system runs from a 9V battery, and we’re interested to know whether there were any tricks pulled to make the battery last.

The system’s software is a simple program built in MIT App Inventor. Still, it’s pretty cool that you can get functionally close to a production product with parts that are very much lying around. It also makes us think of maybe keeping our childhood Meccano sets a little closer to the bench!

The Consumer Electronics Show in Las Vegas is traditionally where the big names in tech show off their upcoming products, and the 2020 show was no different. There were new smartphones, TVs, and home automation devices from all the usual suspects. Even a few electric vehicles snuck in there. But mixed in among flashy presentations from the electronics giants was a considerably more restrained announcement from a company near and dear to the readers of Hackaday: Arduino is going pro.

While Arduino has been focused on the DIY and educational market since their inception, the newly unveiled Portenta H7 is designed for professional users who want to rapidly develop robust hardware suitable for industrial applications. With built-in wireless hardware and the ability to run Python and JavaScript out of the box, the powerful dual-core board comes with a similarly professional price tag; currently for preorder at $99 USD a pop, the Portenta is priced well outside of the company’s traditional DIY and educational markets. With increased competition from other low-cost microcontrollers, it seems that Arduino is looking to expand out of its comfort zone and find new revenue streams.

That’s a Lot of Pins

The Portenta H7 is obviously a far cry from the relatively dinky 8-bit Arduinos that we’ve all got filling up our parts drawers. Developed for high performance edge computing applications, the new board is powered by a 32-bit STM32H747XI that utilizes both an ARM Cortex M7 and an M4 running at 480 MHz and 240 MHz respectively. The two cores can work independently, allowing for example one core to run interpreted Python while the other runs code compiled in the Arduino IDE. When they need to work together, the cores can communicate with each other via a Remote Procedure Call (RPC) mechanism.

Outwardly, the new board doesn’t look far removed from the modern Arduino form factor we’re used to. The USB connector has been upgraded to a Type-C, but the Portenta still retains the dual rows of pads ready for hand-soldered headers — that’s their more recent pinout that they call the Arduino MKR form factor.

If you look on the back of the board however, you’ll see that they’ve added two 80-pin high density connectors. According to the product page, these are intended to allow the Portenta to simply be plugged into a device as a removable module. The idea being that devices in the field can easily have their Portenta swapped out for an upgraded model. Some digging into the product page documentation section turns up a schematic that lists the connectors as Hirose DF40C-80DP-0.4V(51).

The base model Portenta features 8 MB SDRAM and 16 MB NOR flash, but it can be custom ordered with up to 64 MB of memory and 128 MB of flash should you need it. It’s also possible to delete various interfaces from the board when ordering, so if you don’t want network connectivity or the NXP SE050C2 crypto chip, they can simply be left off. However as of this writing it is unclear as to what minimum order quantity is necessary to unlock this level of customization, or or how much these modifications will change the unit cost.

Year of the Arduino Desktop?

The Portenta H7 is an impressive enough piece of hardware on its own, but when it’s plugged into the optional Carrier Board, things really start to get interesting. The Carrier Board provides full size connectors for all of the onboard peripherals, and according to documentation, turns the Portenta into an eNUC-class embedded computer. There’s even support for DisplayPort to connect a monitor, and miniPCI for expansion cards.

With a fully loaded Portenta H7 slotted into the Carrier Board, it would seem you have the makings of a low-power ARM “desktop” computer. Albeit one that wouldn’t outperform the Raspberry Pi Zero, and which costs several times more.

The Arduino press release and product page doesn’t make any mention of what kind of software or operating system said computer would run, so presumably that’s left as an exercise for the customer. While not particularly well suited to it, the ARM Cortex-M family of processors is capable of running the Linux kernel, so spinning up a “real” OS image for it should be possible. Of course with a maximum of just 64 MB of RAM, you’ll want to keep your performance expectations fairly low.

Where Does Portenta Fit?

We can’t even speculate what a maxed out Portenta would cost, and there’s no pricing or release date for the Carrier Board. But even at $99, the base model Portenta H7 would be a tough sell for hackers and makers who are used to buying dual-core ESP32 boards at 1/10 of the price, or the Teensy 4.0 which has a 600 MHz Cortex-M7 at 1/4 of the price. Which is fine, since this board isn’t intended for the traditional core Arduino audience.

Seeing the carrier board, we can’t help but notice some parallels here with the Raspberry Pi Compute Module. With connections broken out to a SODIMM header, the idea of the Computer Module was to help bridge the gap between the DIY community and the commercial one by offering up a Raspberry Pi in a more rugged form factor that would be easier to integrate into end-user products. But since it wasn’t any cheaper than the stock Pi, there wasn’t a whole lot of incentive to switch over. We haven’t seen consumer products advertising “Raspberry Pi Inside!” so it’s hard to tell if there has been any meaningful adoption from industry.

One has to wonder why any company that has the resources to integrate such an expensive board into their products wouldn’t just come up with their own custom design around the Portenta’s STM32H747XI chip, which even in single quantities, can currently be had for less than $15. The difference may end up coming down to the world-renowned community that surrounds the Arduino brand, and the company’s efforts to modernize their toolchain.

If you want a red piece of paper, or a blue pen, what does that really mean? If you’d like to get more specific, Michael Klements’ Arduino-based scanner lets you quantify colors in numerical RGB values via a TCS34725 sensor.

User interface for the handheld device is extremely simple, with a single button to trigger the sensor and measure colors, along with a 16×2 panel. An optional RGB LED attempts to copy the shade of whatever object you’re aiming at, providing a handy reference to verify it’s working correctly. 

You can see the build process in the video below, first constructed on a breadboard and then placed in a more permanent soldered configuration with a 3D-printed case.

When you’re a kid, remote control cars are totally awesome. Even if you can’t go anywhere by yourself, it’s much easier to imagine a nice getaway from the daily grind of elementary school if you have some wheels. And yeah, R/C cars are still awesome once you’re an adult, but actual car-driving experience will probably make you yearn for more realism.

What could be more realistic and fun than an active suspension? Plenty of adults will never get the chance to hit the switches in real car, but after a year of hard work, [snoopybg] is ready to go front and back, side to side, and even drift in this super scale ’63 Oldsmobile Dynamic 88 wagon. We think you’ll agree that [snoopybg] didn’t miss a detail — this thing makes engine noises, and there are LEDs in the dual exhaust pipes to simulate flames.

An Arduino reads data from a triple-axis accelerometer in real time, and adjusts a servo on each wheel accordingly, also in real time, to mimic a real car throwing its weight around on a real suspension system. If that weren’t cool enough, most of the car is printed, including the tires. [snoopybg] started with a drift car chassis, but even that has been hacked and drilled out as needed.

There are a ton of nice pictures on [snoopybg]’s site if you want to see what’s under the hood. We don’t see the code anywhere, but [snoopybg] seems quite open to publishing more details if there is interest out there. Strap yourself in and hold on tight, because we’re gonna take this baby for a spin after the break.

If this is all seems a bit much for you, but you’ve got that R/C itch again, there’s a lot to be said for upgrading the electronics in a stock R/C car.

Via r/duino

[Gurpreet] fell in love with the peaceful, floaty theme from the Avatar series and bought a kalimba so he could hear it resonate through his fingertips. He soon realized that although it’s nice to play the kalimba, it would be a lot cooler if it played itself. Then he could relax and enjoy the music without wearing out his thumbs.

After doing a bit of experimentation with printing tine-plucking extensions for the servo horns, [Gurpreet] decided to start the design process by mounting the servos on a printed base. The servos are slotted into place by their mounting tabs and secured with hot glue. We think this was a good choice — it’s functional and it looks cool, like a heat sink.

[Gurpreet]’s future plans include more servos to pluck the rest of the tines, and figuring out how feed it MIDI and play it real time. For the demo after the break, [Gurpreet] says he lapel mic’d the kalimba from the back and cut out the servo noise with Audacity, but ultimately wants to figure out how to quiet them directly. He’s going to try lubing the gears and making a sound-dampening enclosure with foam, but if you have any other ideas, let him know down below.

We don’t see too many kalimba projects around here, but here’s one connected to a Teensy-based looper.

Via [r/arduino]

There’s a trend in corporate America that has employees wear a step counter — technically a pedometer — and compete in teams to see who can get the most number of steps. We wonder how many people attach the device to an electric drill and win the competition easily. However if you want to do your own measurements, [Ashish Choudhary] has plans for making a pedometer with an Arduino. The device isn’t tiny, but as you can see in the video below it seems to work.

For the extra size, you do get some features. For one, there is a 16×2 LCD display and an ADXL335 accelerometer, and you can probably imagine some other cool features for such a device.

The Arduino computes the magnitude of the acceleration, and if it exceeds a certain threshold it adds a step to the step count. Honestly, this is a fun project but it cries out for a more compact form factor. An ESP8266 for example could ditch the display and connect via WiFi to your phone. Then again, your phone can probably do the same job, as could not to mention many smartwatches. But those don’t have nearly as much geek cred as this project.

This is a little large for a hamster. On the other hand, there’s plenty you can do with the accelerometer after you’ve had enough fun counting steps.

Desk chairs are essential tools for the office environment, so why not turn them into a computer input and feedback device? Aarnio, by researchers from several universities, adds this functionality via an Arduino board. It’s able to detect rotation and tilt via an MPU-6050 IMU, and how far it travels along the floor with an optical sensor from a computer mouse.

User feedback is provided by servo motors that can lock individual casters down. A brake setup is also implemented to inhibit rotation of the central axis and a spring is tightened as needed to modify tilt force. 

Testing showed about a 90% feedback recognition in users, and applications could include use as a gaming controller or as an assistive device for those with limited mobility of their hands.

You can read more about Aarnio in its research paper here.