Shared Projects

Board to use ATTiny85 to drive two NeoPixel strands. Sensor input (e.g., photoresistor) available.

Known issues: 0.1uF capacitor needed on reset pin No RX and TX breakout for UART

STM32F103C8T6 “Blue Pill” version of the Zeppelin Design Labs Altura MIDI Theremin.

Details on this remix, including source code, schematics, bill-of-materials, and 3D Printed case files, can be found on GitHub.

ERRATA: The MIDI Out DIN port incorrectly inverts the PA9 (USART Tx) output via Q1. This needs to be modified to either add a second inversion to the Q1 buffer logic to invert it back or to remove the Q1 buffer entirely, as the STM32 output can sink enough current. The simplest in-place fix is the latter, which can be implemented by removing Q1 and R3 and replace them with a LL4148 diode with the anode at pin 3 of the Q1 (i.e. its collector pin and connection point to R2) and the cathode at the PA9 end of R3. The reason for the diode is to make the STM32’s output only sink the MIDI pin to ground. This is needed because without it, the +3.3v output of the STM32 may be enough to turn on the MIDI receiver’s optoisolator since the other side of the MIDI connection is powered via +5v.

Switch Controller for Pulse-Echo

Microscope Ring Light

project page

See http://github.com/pimvanpelt/i2cstump for details.

Powers both rails of a breadboard with 5V from a USB 2 Type A cable.

This is a multi console controller to DB-15 adapter board that I designed to work with my Saturn Pad Demux , SNES to DB15 Adapter and my PSX to DB15 Adapter firmware.

DB15 pinout is compatible with Undamned’s DB15 Pinout. RJ45 cable pads are labeled according to the MC Cthulhu naming convention and wiring guides.

J1: J1 should be closed during programming and updating the board via SPI. It connects RESET from the ATMEGA328P to pin 9 of the DB15 connector. I’m not sure what most Superguns do with pin 9 since it’s not used on any pinouts that I could find. As such J1 should probably only be closed while programming, just in case your Supergun does something silly with pin 9.

SW1: SW1 is connected to pin 3 of the DB15 connector and is used to add credits. If you are using this board in Saturn mode you will need to have SW1 on the board since the Saturn controller doesn’t have a select button. If you are using Playstation or SNES mode, Select on the controller acts as the Coin button so SW1 is optional.

BOM

U1: Atmega328p TQFP32

C1,C2: 0.1uf 0603

R1,R2: 100ohm 0603

R3,R4: 1kohm 0603 or short. (R3 and R4 are meant only for Saturn mode, although you can get away with just shorting them if you don’t want to add the extra resistors.)

Y1: CSTNE16M0V530000R0

SW1: ‎TL3301CF260QJ‎

SiPM board for 50x50x10 mm scintillator

Helps keep everything tidy in the KR TD.

PicoKey Universal 2nd factor based on Attiny84 and ATECC508A. use with the sparkfun Micro USB female breakout board (also fits on cheap chinese clone which I have some of these).

NOTE - this layout had serious issues in regard to the gyro connections which I am currently rectifying in the v2 layout to follow.An STM32F405 brushless quadcopter flight control board. All UART’s and SPI3 broken out along with SWD programming connections. Suitable for configuration with SilF4ware software by Markus Gritsch on RCGroups. See here https://www.rcgroups.com/forums/showthread.php?3294959-SilF4ware-an-STM32F4-port-of-SilverWare Currently awaiting prototype PCB’s for testing so build at your own risk.

The TRS-80 Disk/Video Interface for Models 100, 102, & 200, normally requires a special 40-wire ribbon cable where all of the wires are separated into pairs, and each pair is flipped over once along the way between the computer and the DVI. like this

Another way to achieve that same wire re-mapping, is to connect two standard pin headers back to back. It’s hard to explain verbally how this works, but just hold two connectors, male or female but both the same, two male or two female, up to each other, face to face, or back to back, with the pin1 marks on the same side (polarity notches on opposite sides), and look at where the pin1 marks end up. Each connectors pin1 mark ends up on the opposite connectors pin2.

Because of this, the quickest and easiest way to make a working DVI cable is to butt two cables with female connectors up to each other, joined by a simple male-male “gender changer” 2x20 pin header. like this There are a couple problems with that though. The pins are exposed to shorting. The connector isn’t polarity-keyed, and so it’s possible to connect it upside down. When using with a Model 102 or 200, the pin header goes right into the computer, and then when you remove the cable, the pins can stay in the computer instead of coming out with the cable, and then they are difficult to get out of the computer simply because there is nothing to grab onto with your fingers.

So this board just makes a male-male adapter that is electrically identical to the plain “gender changer” pin header, but with shrouds and polarity notches instead of bare pins. The shrouds protect the pins from shorting. The polarity notches protect against connecting the wrong way. And there is no problem with the pin header getting stuck in the computer.

Parts

2 x shrouded male 2x20 pin header, through hole solder type
like this

Assembly

Solder the two pin headers back to back on the edges of this pcb, with the polarity notches on opposite sides, pin1 marks on the same side.

This is actually a silly project and isn’t really needed to make the adapter. You can solder the two connectors back to back to each other just by laying them on a flat surface, with the pins interleaved, with the connectors moved so one set of pins touches the other. This leaves plenty of space between pin-pairs so that bridging is not a problem. You just need a soldering iron tip that fits in the small gap between the two plastic parts. like this

This pcb just makes it easier. It’s easier to solder the two parts to a pcb like this than to solder them directly to each other.

Usage

Start with a standard 40-wire ribbon cable 20 inches long with standard female IDC plugs w/polarity bumps and strain relief clips on both ends. Plug this adapter onto one end of the cable. Plug the other end into the Disk/Video Interface.

For Models 102 and 200

Plug the free end of the cabe (with the adapter on it) right in to the “System Bus” connector on the rear of the computer.

For Model 100

Make a short (8 inch) ribbon cable with a crimp-on 40-pin DIP plug on one end, and a standard female IDC plug on the other end. Plug the DIP plug into the system bus connector on the underside of the computer, so the free end of the short cable sticks out just past the rear of the computer. Plug the free end of the long cable (with the adapter on it) onto the free end of the short cable.

Raspberry Pi RGB Matrix Adapter for the Raspberry Pi RGB Matrix project on github. This is identical to earlier versions of this same board except of a slimmer outline to provide space for the Ethernet connector on the Raspberry Pi4. This works for all Raspberry Pi’s with 40-pin GPIO header.

USB-GPIB adapter for the AR488 project on the EEVblog https://www.eevblog.com/forum/projects/ar488-arduino-based-gpib-adapter/msg2184323/#msg2184323

Sega FD