Besides the usual home and garden projects, here are some of the things I’ve been working on during the shutdown. I mark March 19th as the beginning of the shutdown for me – it was my last day in the Midland Center for the Arts Scene Shop. I was alone that day, working on the set for “A Gentlemen’s Guide to Love and Murder”. Of course, the show has not gone up, and there is no indication when we will restart.
DMX
Since I can’t be in the theater, I decided it was time to teach myself about DMX – the protocol used for most stage lighting and effects. I sort of missed the transition from manual and proprietary lighting systems to the standardization around DMX. It’s a pretty simple protocol that repeatedly sends a packet of up to 512 bytes over an RS-485 network. Each receiver knows which of the 512 channels it is assigned to, and interprets the value of the it’s bytes into some action. For example, a dimmer would be assigned one channel and would interpret value (0-255) as a brightness level. A spotlight might have many channels controlling colors, pan and tilt motors, and effects wheels. No error correction – if a message is missed the receiver just keeps doing what it was and waits for the next time – which will be in about a 30th of a second.
I read up on the protocol and decided to build some devices using Arduino class micro-controllers. I ended up building a little 48 channel lighting desk and using some receivers from eBay. I also built a receiver using an Arduino Nano that could be programmed to control Neopixels, for example.
3-D Printed Instruments
Solar Fountain
Collin’s 3-d printed cheetah lives in my little solar fountain. I decided to print some other critters so that the cheetah had some company.
Ski Ball
Father’s Day gift from Beth, Ben and the kiddos. A very well made laser cut wooden kit. Fun to assemble, and it has a nice smoky smell too. I need to machine a little bushing to guide the shooter. It’s riding in two holes in the wood now, and it tends to bind up a bit.
Retropie
I couldn’t resist buying a Raspberry Pi 4, and then I had to figure out what to do with it. Running from a SSD Drive instead of an SD card has become popular because it is more reliable and much faster. Native support for this just came out for the Pi 4, but I was a little early, so I used Berryboot – which initially boots from SD and then reboots from a choice of images on the SSD drive. I currently run Nighthawk – which is a Windows 10 look alike (still actually Linux) and Retropie. Retropie emulates many of the 80s and 90s game machines, so if you can get the code for the games you can play Nintendo, Sega, etc, etc games using the Raspberry Pi. Nintendo 64 is about as current as it gets, and there are complaints about performance. With the exception of some sound issues that I have yet to work out, it runs fine for me on the Pi 4
Instrument Cases
3-d printing projects to make cases for Sonoff devices and some electronics toys – Open Bench Logic Sniffer and Bus Pirate.
Annunciator
I -finally- got around to fixing the display on the annunciator and got it mounted above the door in the shop. 3-d printed a plate for the control panel and mounted the display. Also designed and printed holders for the keyboard and the remote for the display.
