PWM is commonly used to control servos and electronic speed controllers (ESC) and is useful for many projects. This tutorial explains PWM and introduces how to wire up and command a servo Part 2 of the tutorial go over reading PWM commands.
The tutorial features the PWM Backback by Bolder Flight. This handy backbpack makes it easy to hookup RC Servo Motors to your Teensy. It features 8 channels of 16 bit PWM output; bused ground, power, and standard servo connectors; and option SBUS communication input.
Darryl McGee and Steve Barile of Conductive Labs have developed the NDLR (pronounced Noodler), a 4-part poly sequenced arpeggiator, chord and drone player based on the Teensy 3.2.
The guys at Conductive Labs came with a unique solution to break down music theory into knobs and controls. The NDLR has four parts that can play up to 8 synths. The PAD part is a chord player. Press one of the 7 chord buttons and all the other parts change notes to match. There are also 2 “Motifs” which are sequenced arpeggiators. The Drone part can play a single continuous note like a traditional drone does… or choose from various retrigging options, such as having the note retrigger on a chord change, the down beat, every beat, up beat, etc.
Among the many advanced features packed into the NDLR is a pattern and rhythm editor that lets you create custom arpeggios. You can also save your patches and settings for later recall with the 8 global slave slots, 20 user patter slots, and 20 user rhythm slots.
John Grant built MyComm, a very clever solar global messaging device.
MyComm is a portable messaging device that allows users to send messages from anywhere on Earth. It uses the Iridium satellite system to offer coverage beyond traditional cellular and WiFi networks. Because it’s solar powered you don’t need to worry about battery life.
Brian Taylor and the team at Bolder Flight Systems have developed a low -latency, deterministic, scalable flight control system.
Bolder Flight Systems is an spinoff from the University of Minnesota UAS Research labs. They found that at the time the they were working on research, they weren’t really happy with the low-cost options out there so they developed their own primarily to better handle latency and determinism. Their development has evolved from using a MPC-Tiny processor and adding a Teensy 3.2 to using a Teensy 3.6 and BeagleBone Black.
They wanted a system that could scale from simple drones to extremely complex aircraft with a large amounts for sensor and actuator I/O. Their efforts have lead to a scalable system to a virtually unlimited number of sensor and actuators while maintaining determinism and a constant, well defined latency.
Technical details (as well as purchasing details) can be found over at Bolder Flight Systems. They have also developed a series of Teensy shields, or Backpacks to allow you to easily add different modules to your Teensy. Low level drivers for for all their sensors are available on GitHub.
The balloon is filled with helium and is equipped with cameras, and iridium satellite modem, a Teensy using Mikal Hart’s GPS code, and a. The balloon achieved and altitude of about 35 km and captured video showing the beginning of the black of space. The payload was recovered using the iridium tracker.
The control voltage (CV) outputs are 12-bit and 0V to 4.096V in range, with a four octave range for pitch.
The device has 3 mapping modes – 0, 1, and 2.
In mapping mode 0, gates 1 to 8 respond to note on and note off messages on MIDI channels 1 to 8. CV outputs 1 to 8 are determined by the pitch of note on messages on MIDI channels 1 to 8. CV outputs 9 to 16 are determined by the velocity of note on messages on MIDI channels 1 to 8.
In mapping mode 1, gates 1 to 8 respond to note on and note off messages on MIDI channels 1 to 8. CV outputs 1 to 8 are determined by the pitch of note on messages on MIDI channels 1 to 8. CV outputs 9 to 16 are determined by the control change message for controller 1 on MIDI channels 1 to 8.
In mapping mode 2, gates 1 to 8 respond to note on and note off messages on MIDI channels 1 to 8. CV outputs 1 to 16 are determined by the pitch bend value of pitch bend messages on MIDI channels 1 to 16.
The 16′ x 8 ‘ wall is made up of 10 4′ x 4’ panels. It has a Teensy 3.2 driving 2560 WS2811 LEDs and uses the FastLED library, ARTNET/DMX protocol, and Jinkx 2.4 software. For power they used 5V 30 Amp switched-mode power supplies (SMPS) for every 512 LEDs.
Loyal J made a cool USB pinball controller, Pinbox Jr, to use on your PC.
The Pinbox JR is a USB controller that gives PC games the feel of playing on a real pinball table. It interfaces with a PC as a USB keyboard and maps the pinball buttons to various keys on the keyboard. The latest version of the Pinbox Jr includes an accelerometer to simulate the tilt feature if you shake the controller.
This small tactile keyboard is super to use with handheld projects. It has 60 keys arranged in a QWERTY layout and number keys arranged in a number pad layout. The board has beginner friendly through hole soldering with a Teensy, 60 pushbuttons, and 10 zener diodes.
Anthony used this thumb board to make a handheld Raspberry Pi. Using the Teensy he was able to add backlight control and low batter monitoring in addition to controlling the keyboard.
Code for the project can be found in the Teensy Thumb Keyboard Github repository. KiCad files are available or you can also order the PCB from Tindie. Finally, you can find the files to 3D print the case used for the handheld Pi project on Thingverse.
Ben Davis, Darcy Neal and Ross Fish collaborated with Paul in early 2017 this Monolith Synth. It was shown at Tested and the San Mateo Maker Faire.
The Monolith Synth is interactive sound sculpture, with 40 “arcade” buttons on the front as a percussive step sequencer and 2 touch-sensitive side panels for direct performance.
Typical usage scene at Maker Faire, with kids and adults playing with it non-stop all weekend long.
This crazy adventure started with Kickstarter reached out to me, only 6 weeks before Maker Faire, looking to showcase 4 successful projects in their booth. They wanted to show “creative tools” and how people used them. So I reached out to a few synthesizer folks I’ve met and who’ve used Teensy. They also suggested bringing it to Tested to make a video. So it began…
From the beginning I had a step sequencer using illuminated arcade buttons in mind. So I quickly designed this little I/O expander board and sent it off to OSH Park’s Super-Swift service.
The whole project came together over just 4 weeks. Our first meetup was just to discuss what to build, followed a week later by our first build night. By then the I/O expander boards had arrived. We made not the final Monolith, but 3 breadboard prototypes, so the software development side could begin!
Another meetup focused only on software. Almost all the software was developed on these prototype panels.
In this picture you can also see the panel layout sketches on the notepad on the right side, and a blue tape model underneath on the table, which we made to get an idea of the overall size.
Ross and Darcy had synthesis plans that needed a signal-controlled PWM waveform and improvements to the envelope feature, so I worked on improvements to the Teensy Audio Library while they wrote the Arduino sketch code.
The day before our next meetup, I started turning those sketches into a design for the laser cutting. I made this 1/4 scale model of the front and side pieces. At this point, none of the back side or interior ribs (for strength) had been designed, and you can see the model lacks the many holes for screws & brackets which joined everything.
Only 2 weeks before Maker Faire we had an epic 13-hour build day where all the final parts were laser cut and assembled. Here’s a photo of Darcy & Ben putting the panels together on my kitchen counter!
All the clear acrylic plastic parts were completely drawn, with all mounting holes, and made that day.
Here’s the complete layout of all parts (mk2017_design):
While the laser did most fabrication work, other steps like countersinking for the potentiometers were needed. It was indeed an epic 13 hour day of making.
A couple days later, I spent a whole day completing the wiring we couldn’t get done in those 13 hours. Erin Murphy (the “Soldering Goddess” at PJRC) put in a few hours on aesthetic improvements to the messy tangle of wires from so many buttons.
Just a few days later we had our last “build” session, to get the 3 separately written Arduino sketches merged and working together as one integrated project. Even though everything has been designed to go together, this session went very late. Ben did much of the heavy lifting to merge the 3 programs.
This is the final audio DSP system settled upon that late night.
This was the first actual usage of the Monolith, well past 1am when we finally had it all up and running.
The next day I took it all apart and packed all the pieces and spare parts into these 2 big boxes, weighing in at 55 and 40 pounds!
This is the first time I’ve ever shipped a project to Maker Faire, rather than driving a truck or hauling cases of checked baggage on a plane. So much easier, and it allowed time to work on a nice handout card. After some back and forth with the others and last-minute proof reading by Robin, who caught what would have been embarrassing typos and grammatical errors, we sent this card off to be fast-turn printed.
Darcy and I flew to San Francisco early and spent the day with Tested, putting it back together while they shot that awesome video. Sometime I hope to have even 1/10th that sort of video production skill.
Since it was already put together, we had little to do setup-wise. Friday morning Ben, Ross and Darcy did some adjustments of the sound levels which really made it come to life in the space. For anyone who wishes to dig deeper into the technical details, the complete source code is available on Github.
During the 3 days of Maker Faire, things went very well. We did experience a couple minor issues. Massive electrical noise from so many other projects played havoc with the capacitive touch sensing. Saturday evening I rewrote the code to look for changes from an average rather than just an increase from a threshold, which allowed it to usually work well enough. The other tech issue was a bass. When turned up louder, the bass notes would shake all the plastic panels, rattling screws and even some of the connectors loose at time. Easy to fix.
Towards the end of Sunday, the Maker Faire folks came around and gave up an award. At first I shrugged it off, since they’ve done the same for other stuff I’ve brought in prior years. But those were the blue ribbons. Apparently the only hand out one of these red one each in “zone”. They said it’s a big deal…
Really, the best thing about this year was working with a great team. Ross, Darcy and Ben really stepped up and did a great job on so many parts.
Shortly after Maker Faire 2017, this article was posted to the DorkbotPDX website. Since that time, the DorkbotPDX blog section has vanished. We’re reposting it here, to preserve this project’s history. A copy of the original can also be found at the internet archive.
