Shared Projects

Blog post about teardrops in KiCad

KiCad teardrop action plugin

KiCad design files on GitHub

Balanced Audio Pre-Amp Board

Takes a low level PWM input to drive a half bridge pair of fets.

An audio to PWM board utilizing the LTC6992 PWM IC. Takes in audio and spits out low level PWM. Pots to adjust audio gain and carrier level.

A 60A fuseboard.

Fuses: Digikey Mouser

A parallel PTC (resettable) fuse board.

Fuses from Digikey or Mouser

Two parallel p-channel mosfets with under voltage detector ~3.2v for single or parallel batteries.

Tin exposed traces.

Wire with 24 and 14 or 16 gauge wire.

Off board, wire battery negative contact to 510 negative ring, 14 or 16 gauge wire.

Parts: https://www.mouser.com/ProjectManager/ProjectDetail.aspx?AccessID=8e6b935a24

Want to use the board with 2 batteries in series? Well you can. The 14.3K (R2) resistor will need to be replaced with one of a different value.

Use this voltage divider calculator: http://www.raltron.com/cust/tools/voltage_divider.asp

Enter the following

• Input voltage: The appropriate under voltage value (example 6.4v should be good for 2S)
• R1: 100000 ohms
• R2: leave blank
• Output voltage: 0.4v (this is a reference voltage for the voltage detector)

Click compute and you’ll get the R2 value. Go to Mouser and search for surface mount resistors, select one close to R2, case code in 0805.

Want to use 3-4 batteries in series? Do the same as above. Also, the mosfets MUST be replaced with 2 of the following instead: http://www.mouser.com/ProductDetail/Vishay-Semiconductors/SI7633DP-T1-GE3/?qs=LWWr1WFOkdG4pdeq2lDwHw%3D%3D

Due to voltage limitations of components, DO NOT exceed 4S.

The worlds smallest Game Boy cart flasher!

Requires https://oshpark.com/shared_projects/OUjmrtRg to flashing the firmware

BOM

1.1 Changelog:

• Added indicators for the chips and header to make the pcb easier to assemble

• Added indicator for LED positioning

• Reduced pcb height by 0.3mm

• Fixed positioning of cartridge reader guide holes

• Renamed IC1 and IC3 to make more sense

1.2 Changelog:

• Reduced pcb height by 1.4mm

• Relocated componetnts to fit within the new size

• Modified footprint for cart reader

• Replaced the crystal (ECS-60-32-5PXDN-TR) with FQ1045A-6.000 to as this component is only 1.7mm tall instead of 4.3mm

1.3 Changelog:

• Fixed incorrect crystal footprint

1.4 Changelog:

• Fixed incorrect wiring to crystal

1.5 Changelog:

• Replaced the micro usb port with a USB Type C port

• Removed the ISP header in favor of flashing using the cart bus https://oshpark.com/shared_projects/OUjmrtRg

• Replaced the crystal with one that is smaller and does not require 2 capacitors

• Removed redundant capacitors

• Removed the leds for TXD and RXD and their resistors

• Reduced board width by 0.3mm

• Reduced board height by 1.8mm

• Reduced board layers from 4 to 2, this cuts the price in half

• Reduced the size of the cart reader footprint, this now requires some trimming of the pins to fit

A clip-on sensor for Nextion/TJC HMI touchscreens

Control board for Nixie Tube alarm clock. * Full multiplexing of four Nixie tubes (full anode and cathode control). * Also includes three indicator outputs (INS-1 tubes or equivalent). * Time kept with MCP7940 RTC. * ATmega168PB with standard AVR debug connector. * Can be configured as regular clock with/without alarm functionality. Contact smith_brandon at hotmail dot com for more information. SE1079 2019B

High-voltage Nixie Tube power supply, converting ~12 VDC to ~200 VDC for use with Nixie tubes. * Based on MC34063 switching regulator. * Potentiometer allows dialing the desired output voltage. * For more information, contact smith_brandon at hotmail dot com. SE1078 2019B

128K RAM plus EPROM for TRS-80 MC-10. Additional files & info at: http://bit.ly/MCX128_Essentials

SMS to GG cartridge adapter, Rev. 2