Get You an E-Textiles Sensor That Can Do Both

[Admar] is a software developer who was introduced to e-textiles in 2011. The bug firmly took hold, and these days he gives e-textile workshops at Eindhoven University of Technology. Here, students learn to build a single e-textile sensor that detects both presence and pressure. The workshop presentations are available on his site, which is itself a window into his e-textile journey.

Over the years, [Admar] has discovered that any e-textile project requiring more than a few connections is ripe for some kind of textile-friendly multi-point connector. Through trial and error, he designed a robust solution for use with an embroidery machine. The wires are made from conductive thread and soldered to a row of male header pins to make the transition out of fiber space. This transition requires solder, which quickly gets interesting when coupled with a fabric substrate and no solder mask. We wonder if spraying on mask beforehand would help, or if it would just soak in and stain and get in the way.

You can see the connector in practice in [Admar]’s capacitive multi-touch demo video after the break. He has stacked two pieces of fabric, each with a wire bus made of conductive threads, with the traces at right angles. Both sensors are wired to a Cypress PSoC5 to create a sensor matrix, and then to a laptop for visualization purposes. As his fingers approaches the fabric, the bar graphs roar upward to show increased capacitance. Once he makes contact, each finger appears as a yellow dot illustrating pressure.

E-textile projects aren’t limited to traces sewn by hand or embroidery machine. Circuit boards can be knitted, too.

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Pocket Woodwind MIDI Controller Helps You Carry a Tune

It’s easy to become obsessed with music, especially once you start playing. You want to make music everywhere you go, which is completely impractical. Don’t believe me? See how long you can get away with whistling on the subway or drumming your hands on any number of bus surfaces before your fellow passengers revolt. There’s a better way, and that way is portable USB MIDI controllers.

[Johan] wanted a pocket-sized woodwind MIDI controller, but all the existing ones he found were too big and bulky to carry around. With little more than a Teensy and a pressure sensor, he created TeensieWI.  It uses the built-in cap sense library to read input from the copper tape keys, generate MIDI messages, and send them over USB or DIN. Another pair of conductive pads on the back allow for octave changes. [Johan] later added a PSP joystick to do pitch bends, modulation, and glide. This is a simple build that creates a versatile instrument.

You don’t actually blow air into the mouthpiece—just let it escape from the sides of your mouth instead. That might take some getting used to if you’ve developed an embouchure. The values are determined by a pressure sensor that uses piezoresistivity to figure out how hard you’re blowing. There’s a default breath response value that can be configured in the settings.

TeensiWI should be easy to replicate or remix into any suitable chassis, though the UV-reactive acrylic looks pretty awesome. [Johan]’s documentation on IO is top-notch and includes a user guide with a fingering chart. For all you take-my-money types out there, [Johan] sells ’em ready to rock on Tindie. Check out the short demo clips after the break.

We saw a woodwind MIDI controller a few years ago that was eventually outfitted with an on-board synthesizer. Want to build a MIDI controller ? , like this beautiful build that uses hard drive platters as jog wheels.

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Gravity Defying Drips of a Bike Pump Controlled Fountain

People love to see a trick that fools their senses. This truism was in play at the Crash Space booth this weekend as [Steve Goldstein] and [Kevin Jordan] showed off a drip fountain controlled by a bike pump.

These optical illusion drip fountains use strobing light to seemingly freeze dripping water in mid-air. We’ve seen this before several times (the work of Hackaday alum [Mathieu Stephan] comes to mind) but never with a user input quite as delightful as a bike pump. It’s connected to an air pressure sensor that is monitored by the Arduino that strobes the lights. As someone works the pump, the falling droplets appear to slow, stop, and then begin flowing against gravity.

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Precision Pressure In A Piston

[Scott] is building a DIY yeast reactor for his aquarium. What’s a yeast reactor? [Scott] wants to pump carbon dioxide into his aquarium so his aquatic plants grow more. He’s doing this with a gallon of sugary, yeasty water bubbling into a tank of plants and fish. In other words, [Scott] is doing this whole thing completely backward and utilizing the wrong waste product of the yeast metabolism.

However, along the way to pumping carbon dioxide into his aquarium, [Scott] created a very high precision pressure sensor. It’s based on a breakout board featuring the MS5611 air pressure sensor. This has a 24-bit ADC on board, which translates into one ten-thousandths of a pound per square inch of pressure.

To integrate this pressure sensor into the aquarium/unbrewery setup, [Scott] created a pressure meter out of a syringe. With the plunger end of this syringe encased in epoxy and the pointy end still able to accept needles, [Scott] is able to easily plug this sensor into his yeast reactor. The data from the sensor is accessible over I2C, and a simple circuit with an ATmega328 and a character LCD displays the current pressure in the syringe.

We’ve seen these high-resolution pressure sensors used in drones and rockets as altimeters before, but never as a pressure gauge. This, though, is a cheap and novel solution for measuring pressures between a vacuum and a bit over one atmosphere.

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Reviving a Dead Zanzithophone

It’s great to hear from people who say they’re inspired to fix stuff by reading about hacks here on Hackaday. [Michael Lüftenegger] from Salzburg is one of them. About a year back, he snagged a digital horn from eBay that turned out to be dead-er than advertised and he wrote a post about how he fixed it and gave it a second life.

The Casio DH-100 is an electronic MIDI digital wind controller/synthesizer musical instrument. Your breath flows through the instrument, making it feel pretty similar to acoustic wind instruments. [Michael]’s unit had already seen some attempted, but unsuccessful repairs. Nothing that could not be fixed, except that the main pressure sensor was missing. Without the sensor, the instrument was practically useless. The eBay seller wasn’t lying when he described the unit as working with breath mode turned off!
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Push Blood Pressure Data To The Cloud Via ESP8266

[Eduardo] contacted us about his success at connecting a blood pressure monitor to the web. He pulled this off by locating the chip responsible for storing the blood pressure data after being measured. It was a simple I2C EEPROM from which he dumped the data a sniffed communications with a 4 bit logic analyzer. [Eduardo] published all of his findings on that communication scheme so check out his post for more on that. The gist of it is that he implemented his reverse engineered protocol using an ESP8266, the ubiquitous cheap WiFi board that has become a go-to for web-connected anything like power monitors and underpowered but awesome server farms. Check out the Hackaday Dictionary entry for more on this board.

[Eduardo] is not the first on the scene with such a device, you can see a Withings device and a blipcare device available on Amazon. What this hack from [Eduardo] does provide is evidence of a much cheaper route for connecting vital medical data from a geographically distant, and perhaps technophobic family member. Lets take a walk down hypothetical lane, shall we? Uncle Bob in Albuquerque who doesn’t have any local family might be a good candidate for such a hacked device, everyone knows it’s like pulling teeth to get elderly family members to report some health information to loved ones… but with [Eduardo’s] hack it’s simple. Embed the hardware (assuming you know the login creds ahead of time) into a new BPM, send it to him as a gift, and Bob’s your uncle.

We haven’t seen too many blood pressure monitor hacks, but one entry from the Hackaday Prize dubbed “the pain machine” included monitoring the user’s blood pressure. We also covered an interesting hack on monitoring your heart rate with a piezo element.

A quick demo of [Edward’s] cuff is found below.

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Temperature, Altitude, Pressure Display

During a recent trip to Bhutan, [electronut] wished for a device that would show the temperature and altitude at the various places he visited in the Kingdom. Back home after his trip, he built this simple Temperature, Altitude and Pressure Display Device using a few off the shelf parts.

Following a brief search, he zeroed in on the BMP 180 sensor which can measure temperature and pressure, and which is available in a break-out board format from many sources. He calculates altitude based on pressure. The main parts are an Arduino Pro Mini clone, a BMP180 sensor and a Nokia 5110 LCD module. A standard 9V battery supplies juice to the device. A push button interface allows him to read the current parameters when pressed, thus conserving battery life.

Standard libraries allow him to interface the LCD and sensor easily to the Arduino. He wrapped it all up by enclosing the hardware in a custom laser cut acrylic box. The result is bigger than he would like it to be, so maybe the next iteration would use a custom PCB and a LiPo battery to shrink it in size. While at it, we think it would be nice to add a RTC and some sort of logging capability to the device so it can store data for future analysis. The schematic, code and enclosure drawing are available via his Github repository.