We always love to see projects where you can build your own lab equipment so [CompactDIY’s] homemade seismograph caught our eye. The design uses an Arduino with an accelerometer and builds on one of their earlier projects. You can see a video of the device below.
The principle is simple. A hobby servo controls a pen and a stepper motor rolls paper, creating a makeshift strip recorder. Its software uses the Visuino system, which is a flowchart-like system, but it outputs Arduino code. Honestly, we would probably have just plotted the data on a PC, but there’s a certain charm to the strip recorder and the idea would work for other types of data recording projects, too. We thought if you rearranged the stepper motor and cut a paper disk out, you could also have a circular chart recorder easily, which wouldn’t need to friction transport the paper. A clock motor would make it even less dependent on software, too.
[Peng Zhihui] seems to have found some spare time and energy to crack out another sweet robot build, this time it’s a much smaller, and cuter emoji-bot (Original GitHub Link,) with the usual production-ready levels of attention to detail. With a lot of fine details in the 3D printed models, this is one for SLS printing in nylon, but that can be done for a reasonable outlay, in China at least. The electronics package consists of a few full custom, and tiny, PCBs designed with Altium Designer, with off-the-shelf modules for the circular LCD and camera. The main board hosts an STM32F405 and deals with the display and SD card, The reason for this choice of STM32 was due to the requirement for connecting to an external USB3300 high-speed USB PHY. There is a sensor PCB which handles the gesture sensor, a USB hub, MPU6050 9-axis sensor, and also the USB camera module. This board attaches to the USB-C connector in the base, via a FFC cable, allowing the robot to rotate on its base.
[Peng] clearly has exacting standards as to how things should work, and we guess wanted to have the arms back-driveable in a way that enabled the host computer to track and record the motor positions for replaying later on. The connection back to the controller is via I2C, allowing all five servos to hang on the same bus, saving previous resources. Smart! Getting a processor and motor driver in such a tiny space was a bit of challenge, but a walk in the park for [Peng] as is demonstrates in the video embedded below (We believe English subtitles are pending!) The arm mechanism is particularly interesting, and rather elegantly executed, and he does seem rather proud of this part of the design, and so he should! Like with [Peng’s] other projects, there is a lot to see, and plenty of scope for feature explosion. It was nice to see the ‘bot being used as an input device, not only with gesture sensing via the dedicated sensor, but also using the camera with OpenCV to track user posture and act accordingly. This thing could act as genuinely useful AI device, as was a being darn cute at the same time!
Active suspensions are almost a holy grail for cars, adding so much performance gain that certain types have even been banned from Formula 1 racing. That doesn’t stop them from being used on a wide variety of luxury and performance cars, though, as they can easily be tuned on the fly for comfort or improved handling. They also can be fitted to remote controlled cars as [Indeterminate Design] shows with this electronic servo-operated active suspension system for his RC truck.
Each of the four servos used in this build is linked to the mounting point of the existing coilover suspension on the truck. This allows the servo to change the angle that the suspension is positioned while the truck is moving. As a result, the truck has a dramatic performance enhancement including a tighter turning radius, more stability, and the capability of doing donuts. The control system runs on an Arduino with an ESP32 to enable live streaming of data, and also includes an MPU6050 to monitor the position of the truck’s frame while it is in motion.
There’s a lot going on in this build especially with regard to the control system that handles all of the servos. Right now it’s only programmed to try to keep the truck’s body relatively level, but [Indeterminate Design] plans to program several additional control modes in the future. There’s a lot of considerations to make with a system like this, and even more if you want to accommodate for Rocket League-like jumps. Continue reading “Remote Controlled Car Gets Active Suspension”→
Ever wanted your own gesture-controlled robot arm? [EbenKouao]’s DIY Arduino Robot Arm project covers all the bases involved, but even if a robot arm isn’t your jam, his project has plenty to learn from. Every part is carefully explained, complete with source code and a list of required hardware. This approach to documenting a project is great because it not only makes it easy to replicate the results, but it makes it simple to remix, modify, and reuse separate pieces as a reference for other work.
[EbenKouao] uses a 3D-printable robotic gripper, base, and arm design as the foundation of his build. Hobby servos and a single NEMA 17 stepper take care of the moving, and the wiring and motor driving is all carefully explained. Gesture control is done by wearing an articulated glove upon which is mounted flex sensors and MPU6050 accelerometers. These sensors detect the wearer’s movements and turn them into motion commands, which in turn get sent wirelessly from the glove to the robotic arm with HC-05 Bluetooth modules. We really dig [EbenKouao]’s idea of mounting the glove sensors to this slick 3D-printed articulated gauntlet frame, but using a regular glove would work, too. The latest version of the Arduino code can be found on the project’s GitHub repository.
Most of the parts can be 3D printed, how every part works together is carefully explained, and all of the hardware is easily sourced online, making this a very accessible project. Check out the full tutorial video and demonstration, embedded below.
A spirit level, you know the kind of level with a little bubble in a tube of fluid, is a basic construction tool. [DesignBuildDestroy] took an Arduino, a gyroscope chip, and an OLED, and made a 3D printed level with no bubble, but it does have a nice digital display.
It is funny when you realize that at one time a gyroscope was a high tech item reserved for missiles and aircraft. Now you can grab a six-axis sensor for pennies. Even, better, the code used in the project can offload the Arduino for a lot of processing.
We suppose it’s a bit early to call it just yet, but we definitely have a solid contender for Father of the Year. [DIY_Maxwell] made a light-up hockey game for his young son that looks like fun for all ages. Whenever the puck is hit with the accompanying DIY hockey stick (or anything else), it lights up and produces different sounds based on its acceleration.
Inside the printed puck is an Arduino Nano running an MPU6050 accelerometer, a 12-NeoPixel ring, and a piezo buzzer. [DIY_Maxell] reused a power bank charging circuit to charge up the small LiPo battery.
The original circuit used a pair of coin cells, but the Arduino was randomly freezing up, probably because of the LEDs’ current draw. Be sure to check out the video after the break, which begins with a little stop motion and features a solder stand in the shape of a 3D printer.
For his final project in UCLA’s Physics 4AL program, [Timothy Kanarsky] used a NodeMCU to smarten up a carefully dissected NERF football. With the addition to dual MPU6050 digital accelerometers and some math, the ball can calculate things like the distance traveled and angular velocity. With a 9 V alkaline battery and a voltage regulator board along for the ride it seems like a lot of weight to toss around; but of course nobody on the Hackaday payroll has thrown a ball in quite some time, so we’re probably not the best judge of such things.
Even if you’re not particularly interested in refining your throw, there’s a lot of fascinating science going on in this project; complete with fancy-looking equations to make you remember just how poorly you did back in math class.
As [Timothy] explains in the write-up, the math used to find velocity and distance traveled with just two accelerometers is not unlike the sort of dead-reckoning used in intercontinental ballistic missiles (ICBMs). Since we’ve already seen model rockets with their own silos, seems all the pieces are falling into place.
The NodeMCU polls the accelerometers every 5 milliseconds, and displays the data on web page complete with scrolling graphs of acceleration and angular velocity. When the button on the rear of the ball is pressed, the data is instead saved to basic Comma Separated Values (CSV) file that’s served up to clients with a minimal FTP server. We might not know much about sportsball, but we definitely like the idea of a file server we can throw at people.