I decided I need a pick and place machine for assembling electronics for myself and my clients.

I am in the process of documenting this project, which is built on a Raspberry Pi 3, custom circuitry for IO and interface, software in Python and C.  Source files need to be sanitized and will eventually be available on github.

Rendering from KiCad 5

I’ve been working on an audio step sequencer for the Hackaday Prize Musical Instrument Challenge.  The breadboard prototype is working nicely, and boards from JLCPCB should arrive this week.  The device is somewhat of a “shield” for the Teensy 3.6, incorporating elements from the Teensy audio shield, 2.4 inch TFT touch screen, microphone, additional flash, rotary encoders, APA102 LEDs, and a grid of pushbuttons.  I’m working heavily on firmware while waiting for PCBs.

Hardware and firmware files can be found here:
https://github.com/trailhead/teensy-beats

Friends have been asking about our K40 Chinese laser cutter.  Here’s some quick info about our setup.

This is our current setup.  The machine currently goes for $418 or less on Ebay.  I don’t recommend buying the absolute cheapest one, and look for one with reviews.  Shipping is generally free.  It includes an highly inadequate exhaust fan, and a minimal water cooling pump and hoses.  Out of the box, it works ok and requires installing the included, pirated copy of Corel Draw on a Windows machine.  We used VirtualBox to “firewall” the software.  Below the table is a bucket filled with distilled water and the aquarium pump, which pushes cooling water through the laser tube.

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This laser spirograph is constructed from a 5v red laser module, 2 DC motors salvaged from printers, mirrors cut from hard driver platters, 3d printed mounts, and an Arduino Pro Mini which varies the speed of the two motors using PWM and random sinusoidal waveforms.  The case is laser cut from 1/8″ birch plywood.

These LED light boxes were developed as an experiment in product design and development.  I have designed two variants.  One works with 3x AA batteries, the other uses a 5v 2A plug-in power supply.  The objective was to design a product from start to finish in a way that could be manufactured at home on a small scale, and sold in craft and art venues.

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Wemos D1 Mini clone

I’ve been experimenting with MicroPython 1.9.3 on some Wemos D1 Mini boards I have.  I suspect they’re clones, but seem to work fine.  My project is to port a MQTT data logging temperature and light sensor that I created in Arduino a while back.  I’ve encountered a few details that might be helpful to others. Continue reading →