Test board for TL7700 based Pop Stopper.

Connect the ¼" to your headphones, and the 1/8" to your amp. The amp will see the two 150ohm resistors on the bottom on the board instead of your headphones for the first two-ish seconds after power on, so the POP of amp startup goes into the resistors, not your headphones. Similarly, on amp shut-down, it disconnects the headphones as quickly as it can before the shut-down pop hits your ‘phones.

Components on the board are labeled by value. None of the components pass audio (only the connectors and relay), so they can be of common low precision, nothing special, junk drawer quality.

The SOIC is a Texas Instruments TL7700 Reset controller: http://www.ti.com/product/TL7700 Note that the outline on the board is too narrow (my bad, sorry). I had to fold the pins under the chip to solder it to the board.

¼" connector is Neutek NRJ6HF, something like: http://www.mouser.com/ProductDetail/REAN/NRJ6HF-AU

Relay is HK19F type, like: http://www.ebay.com/itm/381374965631

esp-85s

Details https://github.com/bwshockley/Minifigure-SAMD21E

New version 1.3 HERE

Mightyduino

A DIY Arduino type hardware board based on ATmega644p Atmega1284p

Hosted on Github

This project is free and based on @MCUDude’s MightyCore which has awesome well designed kits for serious development with AVR’s.

Mightyduino is an Arduino with more memory than an Arduino Pro mini. It can use 644p (64k) or 1284p (128k) chips. It’s voltage can be configured by U1 and the frequecy can be configured by the Murata’s ressonator (crystal). It has a power led and another one connected to pin D0. The push button performs reset. DTR pin can be used to external reset. The RAW pin is the input voltage <16v. The VCC pin is the regulator output and IC voltage, it can be loaded up to peak of 500mA.

To burn the bootloader (optiboot 6.0) you must first install the MightyCore boards on Arduino App , connect the ICSP pins to your bootloader programming hardware (eg. USBASP), select one of MCUDude’s board that meet the specs you use and burn bootloader. Then you can access (ttl-serial dongle) like a normal arduino on the serial pins (like arduino pro mini). Mightyduino uses the ‘standard’ pin mapping.

Version History

• v1.1 - Switched Led from pin D13 to D0, cosmetic improvements
• v1.0 - Initial release

Quick Links:

Order boards from [OSHPark] (https://oshpark.com/shared_projects/XGfDlqgX)

Or download the Gerber files for other pcb maker

Download the schematic PDF

ATmega datasheet 644p 1284p

Screenshots

Components

Top

Bottom

Pin Mapping

Schematic is taken from datasheet of LM2734

Schematic is taken from datasheet of LM2734

NRF24L01-SMD to through-hole adapter

Universal DCC 43A Booster w/Display

Easy to solder through hole ttl serial usb uart bassed on the Microchip mcp2221 / mcp2221a.

Assembled boards available on my Website Documentation is provided on my Github

WS2812B Joiner Board

A flash based cartridge for C64/C128 that provide space for 16 GAME and 16 EXROM cartridges.Github repo

Version 2