Fancy new CNC router. Got tired of paying for laser cutting, only to get back parts with wavy, heat-damaged edges. Banged together a controller based on GRBL last night. It now moves when I tell it to and makes a really satisfying robot-y sound when it does!
I’m a good way into the Oddity v2 rework. Lots of improvements to power management.
Removed power switch. System power is controlled by a latching mosfet circuit. Push one of the knobs to switch on. Microcontroller controls shutdown for fancy functionality like shutdown-on-idle and shutdown on low battery.
Switched out the column drivers for parts that have two mosfets per package. Added pull-up resistors for more reliable operation across the range of input voltages.
Reorganized system layout using a fantastically low-tech design method involving bits of paper and string!
Another interesting LED project. Many many 7-segment displays chained together and driving from an FPGA. Embraces the digital, rather than trying to blend it away like we do.
Link here. Hope he doesn’t mind me borrowing his images.
Short clip of Hearth running the flame effect.
Latest iteration of the fireplace.
ARM Cortex M3 running the Maple bootloader and some low-res graphic effects code drives two 16x32 RGB LED panels, baffled and masked down to 16x16 round pixels. Glossy black Perspex case.
Runs the same code as Oddity. IR remote or Bluetooth replace the knobs on its smaller cousin.
More work on case design. Venting is a must. With all pixels lit, this thing makes a fair bit of heat. I think it might also need a thermal cutoff, just to be safe.
Edit: Files off to be cut. With some luck, they’ll be here in time for the long weekend.
Latest greatest hardware for Hearth mates directly to the first LED module in the chain, minimizing external components and assembly hassle.
The board can be populated in two different configurations: 1) Infrared remote control, relay for remote power control or 2) Bluetooth control (smart phone, tablet, etc..). The board pictured is populated for Bluetooth control.
Printed circuit board lessons learned this time around:
- Quadruple check the files before they go out! I spent a bunch of money and waited a few weeks for a set of completely incorrect boards. Fortunately we were able to salvage one and bodge together a Hearth dev kit for Ishani.
- Don’t use a copper flood if you don’t need one. The soldermask on this batch of boards was a little offset, resulting in some places where it’s easy to bridge a pad to ground unintentionally. In the next rev, the ground plane will be limited to the back side of the board.
- Place footprints for bigger e-caps than you think you need.
- Make sure the board house will use a milling layer if you use one. Mine doesn’t. Consequently, there are some oblong holes that came out small and round. In the next rev, the milling layer will be replaced with stacked drill hits.
Simplified Hearth case design. Faceplate and sides are a single welded unit. LED modules mount directly to the back plate with threaded spacers. Redesigned electronics mate directly with the first panel in the chain. Power, USB and infrared connections exposed through the back panel.
Ishani informs me that yesterday was Worldwide Pinhole Photography Day. Here’s a shot from his brand-new Hearth devkit we assembled in the afternoon.
Prototype standalone board for the fireplace is off for fabrication.
…because sometimes it’s OK to give yourself a pat on the back.
Our pick of the show was the Oddity boxes by software engineers, John Popadic and Harry Denholm mainly because they were so damn cute. These adorable and tiny cubes produced a series of low res visuals that made us want one immediately.
..and finally John Popadic and Harry Denholm combine their talents to build Oddity, a small box of light that allows the user to select a graphics algorithm and play with its inputs to vary the output within a predefined program. Oddity is also a toolkit that comes complete with software that can be altered to produce custom effects using your own imagination.
The original Oddity has some issues with flaky rotary encoders. The encoders are mechanical switches, which don’t generate clean transitions. There are variety of ways to deal with this in software, but all of them take time. I’ve chosen to sacrifice a tiny bit of board space and implement full hardware debounce straight from the Bourns app note to make Oddity revision 2’s controls as silky-smooth as its graphic output.