More information here: https://hackaday.io/project/168448

XBee + PropellerMini WS2812 Controller

This version is untested.

Simple carrier board for E28 12, 20 and 27 dBm modules

Four channel second order filter based on LM324

This board was developed by the VoronDesign community.

Original and uptodate version here: https://github.com/VoronDesign/Voron-Hardware/tree/master/V0_Display The board has:

STM32F042F6P6 MCU with internal oscillator
SWD header for easy debugging (not populated by default)
Dual USB port (Vertical or Horizontal) with breakout pin header for USB header
I2C Screen connections for 1.3" display with jumpers on back for slecting which pins (1 or 2) are power and ground
EN11-style click encoder support
Reset/kill button
3 GPIO pin header
1 on-board Neopixel with data line broken out for expansion

In addition to the PCB and SMD parts (see BOM), you will need:

Encoder Amazon/DigiKey
Kill and Reset Switch 6mm Tactile buttons 4.3mm Tall
An OLED display 1.3"
Pin Header Assortment Male Dupont-Style and/or JST-XH Style (Can be nice for USB as it's polorized)

Optionally you can get:

Neopixels or look on ebay for bare 5050 Neopixels
Micro USB port (Horizontal Molex 105017-0001 or equivalent Amazon) or (Vertical Molex 105017-0001)

A DCC Accessory Decoder to drive four standard servos - based around an Arduino Nano 3 module and incorporating facilities for the precise manual adjustment of all servo throws (as well as via programming of configuration variables (CVs)). This updated version can be powered from a separate Accessory power bus, instead of directly from the DCC track, to reduce the load on the DCC Command Station or Power Booster. Further details at A-Train Systems, Projects (https://www.a-train-systems.co.uk/download.htm#Projects)

uprog2: Universal Programmer for Linux

Programmer firmware and software designed and developed by Jörg Wolfram. http://www.jcwolfram.de/projekte/uprog2/main.php. https://www.mikrocontroller.net/topic/411643

The software and schematic are licensed by Jörg Wolfram as “GPL (GNU General Public Licence) Version 3”

Schematic files, Gerber files and Bill of Materials can be found at https://github.com/5inf/uprog2

Replaced AK9754 with LSM303AGR.

Swapped CCS811INT and CCS811 WAKE to conform with new Katydid pin map.

An Arduino Shield for the Grid SRAM project (https://github.com/DragonMinded/gridsram). Its recommended that you use sockets for all 7400 logic, as well as (obviously) a socket for the SRAM chip. That way, you don’t risk burning out the chips when soldering. There is limited clearance under the board for things like the Arduino USB and the ICSP header. Make sure you snip protruding pins on the bottom side as flush with the board as you can.

BOM:

1x 32 pin DIP socket (https://www.mouser.com/ProductDetail/437-1108763241001101/)

4x 14 pin DIP socket (https://www.mouser.com/ProductDetail/575-1154731441001000/)

1x 74HC00 DIP chip (https://www.mouser.com/ProductDetail/595-SN74HC00N/)

3x 74HC164 DIP chip (https://www.mouser.com/ProductDetail/595-SN74HC164N/)

1x Schottky Diode (https://www.mouser.com/ProductDetail/583-1N5817-T/)

5x 0.1uF ceramic capacitors (https://www.mouser.com/ProductDetail/810-FA28X8R1E10400/)

1x set of arduino stackable headers (https://www.adafruit.com/product/85)

(Mostly) drop-in replacement for the NE558 quad timer using four 555 timer chips. Pins are Mill-Max 0542-0-00-15-00-00-03-0