Shared Projects

This board is a small and cheap pogo pin programming solution designed in my case for a Lattice HW-USBN-2A (2.54mm pitch pin header) and the gMUX JTAG connector on a logic board of a MacBook Pro 15" early 2011 (pogo pins). This connector is not soldered on the logic board, thus I will use the pogo pins.

The pogo pins are TH pads with 1.2mm pitch and hole size of .75mm diameter. I will use this pogo pin: P50-J1 or P50-B1. Both have a .68mm diameter. I will solder the ground pin slightly lower so it is the first to make contact when the pogo pins are pressed on the pads.

The hole in the top left is thought to insert a lanyard.

Feel free to do with it whatever you want (public domain)

BOM

Optional

Changelog

v1:

• Added C1 capacitor
• Minor aesthetic improvements (I hope the text “public domain” is now readable; even more rounded corners)

v0:

• First release (Tested and it works!)

A USB-stick sized UPDI programmer, for programming Microchip’s new 0-series and 1-series ATtiny chips from the Arduino IDE.

For more information see: http://www.technoblogy.com/show?2OJT.

8-bit R-2R DAC Ladder with 0603 resistors in a 10-pin SIP package

PIC-based high-power peripherals handler for Raspberry Pi. Outputs for 2 DC motors. LiPo battery undervoltage protection and indicator.

dsPIC33 microcontroller handling 1 differential encoder input, 1 single ended encoder input , and 2 buffered analog accelerometer inputs. Communicates with a master microcontroller via SPI tether.

GoPack with integrated Maxon ESCON motor driver.

No idea if this works…

32k RAM Expansion - ZX Spectrum Issue 1

I believe it’s by ‘Mark Smith’ and/or ‘Brendan Alford’ - other than having ‘Smith’ on the PCB files I’m not sure. Component list: https://imgur.com/CJDVUBw

2600ms Watchdog, 1-Wire bus master, solder pad selectors to bypass fuse if power is not being made available to external devices, additional IO exported for use with a pulsed type (paddle wheel) water-flow meter.

LED Button fun with a fuse.

Connects to ARM-20 JTAG interface. Note that the power to the personality chip connects to Vsupply and the feeds back into Vref. If Vsupply is unconnected, use the VCC pin on the PCB to provide 3.3V.

Connectors are S9205-ND and S9712-ND.

Original uses P25Q80H. W25Q80DV also works. Depending on flash chip, WP may need to be held high to program.

• U1 - W25Q80DV (W25Q80DVSNIG-ND)
• C1 - 0.1uF 0402
• C2 - 330pF 0402
• R1 - 10k 0402

Schematic

Leonard Heinkelein’s paper tape emulator, allowing direct loading of digital .bin images of HP paper tapes into HP21XX computers using an HP 12566 ground-true I/O card. The original article describing the design, construction and operation of the emulator can be found at the HP Computer Museum, under the description of the 2748 paper tape reader.

http://www.hpmuseum.net/display_item.php?hw=283

Switch Controller for Pulse-Echo rev A

Rectangle version of the PCB Coin Cell. This is the top.

USB connector used: https://lcsc.com/product-detail/USB-Connectors_Jing-Extension-of-the-Electronic-Co-C40939_C40939.html

You need to order the base too - https://oshpark.com/shared_projects/xAnGcWgn

Rectangle version of the PCB Coin Cell. This is the base.

You need to order the Top too - https://oshpark.com/shared_projects/4JOAhueH

Interposer with GND

See also the Updated V2 version of this board which provides SPI display mode support as well.

This board goes inline between a host CPU and an OLED (or similar) I2C graphical display. Its purpose is to convert the graphical display into a character-based display, removing the overhead of font rendering and pixel transfer over the slow I2C bus from the host.

Note that the CPU here is the ATmega328PB (PB version) with dual I2C ports. 12 MHz was chosen for the ceramic resonator, instead of 16MHz or 20 MHz, so that it will run at 3.3v within the specs given in the datasheet. You may, however, be able to overclock it successfully, especially if running at 5v. Be careful, however, of OLED displays with very noisy voltage inverters, as they will interfere with CPU overclocking. I managed to brick two ATmega328PB CPUs trying to run one with this board at 20MHz. 16MHz, however, was no problem.

An identical board with a reversed display connector is also available.

ERRATA: Some I2C displays, like the common SSD1309 2.42" OLED module, require a longer reset pulse than this board currently provides, particularly if the power supply on the display takes a while to settle. If you find your display doesn’t boot correctly, but instead only has a screen garbled with random dots or is otherwise behaving erratically, replace C3 (currently a 0.1uF) with a larger value. It’s recommended to go ahead and make this change during assembly and use a 10uF for C3 of the same ceramic type as C1. During testing, switching C3 from a 0.1uF to a 10uF part has resolved all power-on reset issues encountered.