Shared Projects

Joins 2 APA102 strips back to back, with header for data

Momentary to On/Off Switch Circuit

Parts List:

IC1, IC3, IC4, IC6 - Clare LCC110

IC2, IC5, IC7 - Toshiba TLP222A(F)

R1, R3, R4, R6 - 470Ω, ¼-Watt Resistor

R2, R5, R7 - 390Ω, ¼-Watt Resistor

This board allows you to connect a mini-DIN 6 cable from my GPS Disciplined Oscillator’s diagnostic port to the Raspberry Pi.

The correct part for the mini-DIN 6 jack is the CUI MD-60S. The 3 pin jumper block selects the serial input on the pi to be either the GPS NMEA sentence output or the diagnostic output. The transmit output of the Pi is always connected to the GPS RX pin on the GPSDO. The PPS output of the GPSDO is fed into GPIO 18. The two pin jumper sets whether or not the 5 volt pin from the diagnostic header is connected to the 5 volt bus of the Pi. Powering the Pi from the diagnostic connector is only recommended for the FE-5680A breakout board. Added 5 volt load on the OCXO or TCXO may impact its stability. Attempting to power the oscillator from the Pi is NOT recommended.

Mount a 2x8 .1" DIP female header on the bottom of the board. Install the board on the Pi GPIO header at the left most (pin 1) end. The mini-DIN 6 cable should exit more or less right over the SD card.

The two diodes are just 1N4148s and the two resistors are 10 kΩ.

Lattice iCE40 Ultra FPGA generating MIL-STD-1553 BC/RT network messages.

More details here: http://stevenmerrifield.com/1553/index.html

This is a simple board used in conjunction with my Super-Chuffer product to control the smoke volume of an O-gauge steam locomotive. It lowers the smoke volume when stopped.

RefDes Value Name Manufacturer Pattern C1 33uf 25V EMVA350ADA330MF55G United Chemi-Con CAPAE-6.6x6.6h5.4 D1 DBDB102G DB-DIP D2 DBDB102G DB-DIP D3 DBDB102G DB-DIP D4 DBDB102G DB-DIP J3 B4B-PH-K-S JST HDR-1x4T/2/Sh10x5 J4 B2B-PH-K-S JST HDR-1x2T/2/Sh6x5 K1 Relay IM06DG TE Connectivity GN-A R2 470 SMT 0805 Yageo RES_0805

A dual power supply based on the Muffsy Hifi Power Supply

Breaks out the Raspberry Pi (A or B, Rev. 2) GPIO header to an ARM 20 JTAG header. It will also work with Raspberry Pi A+ and B+, so long as you take care of the 26 to 40 pin conversion. I imagine it will also work with the Raspberry Pi 2, but I’ve not tried it out.

This is for debug access to the ARM core of the Broadcom chip, not the Video IV core.

I use an Olimex ARM-USB-OCD-H JTAG but this should work well enough with any standard ARM 20 JTAG debugger. Note that the DBGRQ and DBGACK pins are unconnected.

There is no pin on the GPIO header to initiate a system reset. Raspberry Pi boards have an unpopulated header (called P6 on Rev. 2 A and B boards, called Run on later boards). Solder in a 2 pin length of breakaway, and connect to the reset header on the JTAG breakout. Connect pin 1 to pin1, pin 2 to pin2. Then the JTAG adapter will be able to initiate a system reset.

The pins are not configured for JTAG by default at system reset. The pins are GPIO pins that have to be configured to alternate functions by software at boot time. For an example,see the armjtag project by David Welch.

The layout of the UART serial port breakout is the same as the Beaglebone Black, This is convenient for connecting USB to TTL serial adapters, such as the FTDI Friend or the FTDI Basic. Like the Beaglebone Black, pins 2, 3 and 6 of the UART header are unconnected.

Apple II Joystick to USB Adapter. Details can be found at www.flitey.com

Soap Bubble Machine

Added PTHs for easy mounting on the bubble display frontpack.

5V 15-watt buck converter PCB

What to do when you have a partial reel of 74AHCT08 chips burning a hole in your pocket? Design a 20 Input AND gate of course.

Yes, this actually works. There are 10k pulldowns on all inputs so that they won’t pick up on noise. Apply logic high signals to all inputs to test it.

I made this board just for fun. Perhaps it would make for a good SMD soldering challenge… I gave one to a Digital Electronics professor who was retiring and he loved it.

BOM

• U1-U5: 74AHCT08 SOIC-14 (or similar logic family)
• U6: 74LVC2G17 SOT-23-6
• D1: B340A Schottky Diode SMA
• PWR LED: 0805 SMD (color of your choice)
• HIGH and LOW LEDs: 1206 SMD (colors of your choice)
• R1-R3: 330 ohm 0603
• Pulldown resistors (back side): 20x 10k ohm 0603
• C1-C6: 100 nF 0603
• C7: 10 uF 1206 SMD 10V (or substitute with ceramic cap)
• 2 Pin Headers: 1x2 0.1" standard header pins
• 40 pin Header: 2x20 0.1" standard header pins

Eagle Files

https://github.com/SyncChannel/20-Input-AND-Gate