A round gauge-face circuit board I designed in Altium Designer at Specialized Solutions, after doing the wrench for the 2018 DEF CON Car Hacking Village badge. A radial array of hundreds of tiny 0404 RGB LEDs (1.0 × 1.0 mm) sweeps around a printed 10 to 100 speed scale, driven by two microcontrollers and six 74HC595 shift registers, powered over micro-USB. The boards were fabricated as a four-up panel, and I assembled them. It was not an official Car Hacking Village badge: I designed it, the owner of Specialized Solutions liked it, and we built a small run, I assembled them, and we sold about 20 at DEF CON 2019. Its SDK appears in the public 2019 Car Hacking Village repo as the “gauge”.
AssembledOne assembled board: two microcontrollers, six 74HC595s, two buttons, micro-USB and the edge pads.PanelAll four boards on the panel, assembled.Machine setupAn early placement run while I was setting up the Samsung CP45 for this board. Some parts came out rotated incorrectly. That happens when a part's rotation in the placement file doesn't match how the machine and feeder define 0°. I used runs like this to correct the orientations in the placement file.DetailClose-up of the LED array and printed scale from the same setup run. A few components here are still rotated incorrectly. Getting every part's orientation right in the placement file is one of the trickier parts of bringing up a new board on a pick-and-place.
Fabricated boards
BoardsBare boards as received from fabrication.
Design
3D render3D view of the board with its components.PlacementFootprint and placement layout: the central ICs and the ring of LEDs.LayoutClose-up with all layers on.RoutingRouted board, all layers.LayerTop layer.LayerBottom layer.LayerInner power layer, with short traces for the LEDs.
