Teensy 3.6 as standalone mediator between USB MIDI and Eurorack

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Sebastian writes:

USB MIDI controllers (such as Launchpad Mini Mk II for example) are common and often quite low in cost.
To interface such a controller with a Eurorack synth system, often a host computer and a MIDI to CV interface might be used. The host computer would take USB MIDI data from the MIDI controller, perhaps store and manipulate that data in some way (e.g. a sequence), using a MIDI to CV converter to then control a Eurorack synth system.
It would be useful to use USB MIDI controllers with Eurorack synth systems without needing a computer and MIDI to CV interface in between the two.
Teensy 3.6 is a great microcontroller that can be programmed using the Arduino IDE. A very useful feature of the Teensy 3.6 is the USB host port.

See the full post on his blog here, Little-Scale.

Check out the video after the break.

The Khadas Edge: A new captain with an edge // Review

In this review I take a look at one of the newer members of the Khadas family; The Khadas Edge and Khadas Captain.
This board has some pretty interesting power management but, unfortunately, I saw the return of the magic smoke genie. Continue reading The Khadas Edge: A new captain with an edge // Review

The post The Khadas Edge: A new captain with an edge // Review appeared first on MickMake.

New 2.5D pen/laser ESP32 controller

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Bdring published a new build:

I have done several pen and laser machines lately, so I decided to create a custom PCB for Grbl_ESP32 for these types of machines. This is a small (70mm x 60mm) PCB with all the features a pen plotter or laser cutter/engraver would need.
These typically use stepper motors for the X and Y axes. On pen plotters, the Z axis is controlled by a servo or solenoid. On lasers you need an accurate PWM for laser power control.

Project info at Buildlog.Net blog and the library GitHub repository here. It’s also up on Tindie.

DakBoard family calendar with Raspberry Pi Zero W and Read Only filesystem

DakBoard Family Calendar

Scott Hanselman made this DakBoard family calendar with Raspberry Pi Zero W and wrote a post on his blog detailing its assembly:

The implementation is simple genius. It’s a browser that starts up full screen (kiosk mode) and just sits there and updates occasionally. DakBoard provides the private webpage and tools to make that happen. You can certainly build this yourself with any number of open source tools. I chose DakBoard because it was simple, beautiful, and I was able to get the whole thing done in less than an hour. I’m sure I’ll spend many hours tweaking it through. There’s also the very popular MagicMIrror platform, so lots of choice and power in this space!

See the full post on his blog here.

The OpenBrite Turbo controller for Vectrex

Vectrex Controller Prototype

Stephen Wylie blogged about his Turbo Vectrex controller build:

 The main impetus for this was to have a homebrew controller that actually featured an analog joystick, since there were few if any guides elaborating how to fashion one from an existing controller.  I acquired a couple Parallax 2-axis joysticks with breadboard mounting capability to do the trick.
The Vectrex comes with a game in its ROM — Asteroids — thus you can play without needing a cartridge.  However, with the traditional controller, this requires lots of button-mashing since it has no auto-fire feature.  Using a 555 timer, potentiometer, and clever values within an RC circuit, I have given it the ability to auto-fire.

See the full post on his blog here, GOSHtastic.

App note: How to achieve greater accuracy in battery capacity readings for portable designs

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App note from Maxim Integrated on using fuel gauge IC to obtain accurate battery state of charge readings. Link here (PDF)

Because a product’s runtime is limited by battery capacity, it’s critical to have a precise method for measuring the remaining battery capacity to avoid an unexpected shutdown. This application note describes an experiment for obtaining accurate battery capacity readings in a dog-tracking project.