Shared Projects

Precompiled HEX-files: https://krikzz.com/forum/index.php?topic=10537.msg78904#msg78904

A basic plug-and-play adapter board for use with the GBS Control project. Using a smaller ESP-12/12F/12E ESP8266 module with appropriate wiring and power decoupling. Also includes pin 37 jumper and I2C pads for Si5351 board.

This project uses an ATmega2560 as a multifunction bus peripheral for homebrew retro computers. Features: 8-bit, 22 kHz stereo audio, micro SD card, dual gamepad connectors (Sega Genesis, 6-button), 512KB RAM for sound samples, etc., AUX connector for I2C, Serial UART, PWM, etc.

At around 16 MIPS at 16 MHz, this CPU is likely to greatly outperform most of the vintage CPU’s this card is intended to be used with. It may be useful to have it perform some floating-point math, etc., on behalf of the main CPU. Despite its speed, the latency of pin-change interrupts is too high to connect this MCU directly to a classic computer bus. Instead, a couple of latches are used: one for reading, and one for writing. These allow the card to look like a single byte in the memory map of the system. This byte may be read or written to communicate with the card. (An 8-bit bidirectional parallel interface.)

An IRQ output is supplied, which may optionally be used to get the system’s attention when a timer expires, new data is available, etc.

I have the firmware started, and the most complete feature so far is the sound. Inspired by the TurboGrafx 16’s sound, it’s capable of driving 8 channels of arbitrary-waveform oscillators, sample playback, direct DAC output from host CPU, pans, and fades. I want to add a LFSR noise generator for percussive sounds, a very small library of drum and synth samples in ROM, the ability to store/play samples from the onboard 512KB SRAM chip, and increase the sample rate to 44.1 kHz, but these features aren’t yet implemented.

I intend to put the code up on GitHub soon. Please let me know (caiannello on geezer male) if you’d like to be notified when this happens, and I will do so.

SCHEMATIC HERE

Geek on! Craig I., pugbutt.com

This board serves as an intermediate between a Red Pitaya and the needed motors & sensors used in a positron emission tomography experiment.

The Piantor Keyboard is a beginner-friendly, easy-to-solder, 42-key or 36-key, diodeless, low profile aggressive column staggered, programmable ergonomic mechanical split keyboard powered by Raspberry Pi Pico or other compatible RP2040 boards. It is based on the Cantor Keyboard.

The Piantor Keyboard is a beginner-friendly, easy-to-solder, 42-key or 36-key, diodeless, low profile aggressive column staggered, programmable ergonomic mechanical split keyboard powered by Raspberry Pi Pico or other compatible RP2040 boards. It is based on the Cantor Keyboard.

This board sits on top of an MMC3 footprint so you can use the smaller SMD133 chip instead

This is the dumbest board I’ve ever made

This is the 3.3V analog output analog shaft encoder designed by FRC Team 4272. The intent of this encoder is to replace the CANcoder or CTRE mag encoder. The intent of this encoder is to go to the Spark MAX 3.3V analog input, for a clean wiring solution,

Eurorack digital effects module - front panel PCB version 1.2

Holes and silkscreen only. No tracks, no pads.

Eurorack digital effects module - controls PCB version 1.2