Anyone who’s ever slept through a morning’s alarm can tell you that sounds, even loud piercing ones, don’t always wake a person out of a deep sleep. Similarly, hearing a baby cry on the other side of the monitor might not always wake a parent up in the middle of the night. So what’s the solution? This haptic baby monitor created by [Guy Dupont] certainly looks like it has some promise.
[Guy] picked up a fairly standard baby monitor from VTech and popped it open to see how he could tie a vibration motor into the original circuitry. He originally thought he’d have to do some signal processing magic to figure out the amplitude of the audio, but then he realized that the five LEDs on the front of the unit that light up to indicate the audio level were already doing the hard work for him.
So he wired each of the LEDs up to the pins of a Seeed Studio XIAO nRF52840 microcontroller, and wrote some code that would poll their status a few hundred times per second. Dividing the total number of LEDs by the count of how many are currently illuminated gives him a nice average that he can use to set the intensity of the vibration motor that he’s built into a stretchy armband.
For extra points, [Guy] is also using the Bluetooth capability of the XIAO to provide a rudimentary configuration service — just connect up to the MCU with a Bluetooth serial application on your computer or phone, and fire off a value between 0 and 10 to augment the motor’s intensity. There’s also a BLE characteristic which can be read from a client device to determine the currently detected audio amplitude, which could be used to chart how well the baby is sleeping over time. Alternately, as demonstrated at the end of the video, you could use it to play Flappy Bird.
It’s an elegant modification that could potentially hold promise for parent’s who need a bit of extra help keeping tabs on their miniature humans. This isn’t the first time we’ve seen hackers try to improve upon the classic baby monitor, but this is arguably the most approachable attempt we’ve seen to date.
Let’s face it, we probably all sit at our computers for way too long without getting up. Yes, there’s work to be done, games to be played, and the internet abounds with people who are wrong and must be down-voted and/or corrected. We totally get and respect all that. However, if you want to maintain your middle- and long-range vision, you should really get up regularly and gaze out the window for a bit.
In fact, the Arduband does you one better. Its Arduino Nano and accelerometer check your position every ten minutes. If you haven’t changed your Z by the third check, then it’s time for a break. The combination of an RGB LED, buzzer, and vibrating disc motor working together should be enough to pull you out of any computerized stupor, and they won’t give up and go back to sleep until you have stood up and remained upright for one minute.
We like that [ardutronics123] spun up a board and made it small enough to be wrist-mounted using a watch strap. It would work just as well worn around your neck, and would probably even fit in your pocket. Blink a few times before you check out the build video after the break.
Virtual reality holds the promise of an immersive experience that can satisfy our senses to a level comparable with… well, reality. The field has come a long way, but Sarah Vollmer makes a good point that many of the VR systems currently in use are bulky and difficult to transfer from person to person.
While headsets have become smaller and lighter and now feature improved motion tracking and resolution, their ability to affect the user’s other senses hasn’t seen nearly the same advancement. Haptic feedback systems need to catch up with headsets, and how to unobtrusively allow users feel simulated physical contact in VR is an area Sarah is researching as part of her PhD work. This is the topic of her 2019 Hackaday Superconference talk which you’ll find embedded below.
The build was borne out of necessity; [bitelxux]’s meter lacked a buzzer, and it grew frustrating to always look at the display. In order to allow late night hacking sessions to go on undisturbed, an unobtrusive vibrating tester was desired, as opposed to the usual audible type. Two whiteboard markers donated their shells to the hack, fitted with small nails to act as probes. Inside, a pager vibration motor is connected, vibrating when continuity is found. The circuit runs from a 1.5V AA battery which neatly fits inside the marker shell.
It’s a basic build, but gets the job done with a minimum of fuss using parts that most makers probably have lying around. Of course, you can always go a slightly more complicated route and throw an Attiny at the problem.
Tiny motors used for haptic feedback and vibration come in a variety of shapes and sizes. The most familiar is the “eccentric rotating mass” (ERM) variety which just spins an imbalanced weight on a small motor and comes packaged in two form factors. The classic is the pager “pager motor” which just looks like a tiny, adorable motor and the squat cylindrical “pancake style”. ERMs are simple to use but provide imprecise response when compared to their new-age cousin the “linear resonant actuator”. Unlike the motor in an ERM, LRAs are typically an enclosed mass on a spring placed near a coil which pushes the mass back and forth. The name LRA might not be familiar but Apple’s branded implementation, the Taptic Engine, might be a little more recognisable.
[Precision Microdrives] is a vendor of these sorts of devices who happens to have a pleasantly approachable set of application notes covering any conceivable related topic. A great place to start is this primer on ways to drive motors with constant voltage in a battery powered environment. It starts with the most simple option (a voltage divider, duh) and works through a few other options through using an LDO or controller.
If you’re thinking about adding haptics to a project and are wondering what kind of actuator to use (see: the top of this post) AB-028 is a great resource. It has a thorough discussion on the different options available and considerations for mounting location, PCB attachment, drive modes, and more. Digging around their site yields some other interesting documents too like this one on mounting to fabric and other flexible surfaces. Or this one on choosing PWM frequencies.
Similar smartwatches exist to detect oncoming attacks, but they don’t do anything to combat them. Minder is like having a friend strapped to your wrist that’s never absorbed in their own problems. It wants to help no matter what it takes, which is why it features multiple techniques for getting back to a state of calm.
Minder’s brain is the bite-size Qduino Mini, which is great for a crowded wearable because of its built-in charging circuit. It uses heart rate and temperature sensors to determine the onset of a panic attack, and a vibration motor to alert the user. The motor also plays a part in the relaxation techniques to keep the user focused and in control. Use the upcoming break to relax and check out the video.
We have seen a few of these types of devices in the past, and they almost always use ultrasonic sensors to gauge distance. Not so with this ETA; it uses six VL53L0X time-of-flight (ToF) sensors mounted at slightly different angles from each other, which provides a wide sensing map. It is capable of detecting objects in a one-meter-wide swath at a range of one meter from the sensors.
The device consists of two parts, a wayfinding wand and a feedback module. The six ToF sensors are strapped across the end of a flashlight body and wired to an Arduino Mini inside the body. The Mini receives the sensor data over UART and sends it to the requisite PIC32, which is attached to a sleeve on the user’s forearm. The PIC decodes these UART signals into PWM and lights up six corresponding vibrating disc motors that dangle from the sleeve and form a sensory cuff bracelet around the upper forearm.
We like the use of ToF over ultrasonic for wayfinding. Whether ToF is faster or not, the footprint is much smaller, so its more practical for discreet assistive wearables. Plus, you know, lasers. You can see how well it works in the demo video after the break.