Shared Projects

Prototype nRF51822 board for testing sensor interfaces and BT programming.

www.freedsp.cc

spdif2

I designed this as a universal USB charger for phones and tablets. Vin = +8-12V, Vout = +5V @ 1A. I’m using one or two 8-AA battery packs for Vin depending on how much current is required at the output.

It uses the LM2675-ADJ from TI as U1. By choosing the appropriate inductor L1, input and output capacitors C1 and C2, and feedback resistors R1 and R2, this can be configured for other output voltages. R3 to R6 set voltages on the D- and D+ USB lines to allow for Apple device charging up to 1A (as discussed by Adafruit’s Lady Ada here).

Components: LM2675-ADJ, PDIP-8 package L1 = 33uH, CoilCraft DO3316P-333 C1 = 150uF, low-ESR aluminum electrolytic cap, Panasonic EEE-FP1V151AP C2 = 100uF, low-ESR aluminum electrolytic cap, Panasonic EEE-FP1V101AP C3 = 0.01uF, 0805 ceramic cap D1 = 20V 3A Schottky diode, DO214AC package R1 through R6 all 0805, 1%: R1 = 1k, R2 = 3.16k, R3 = 43k, R4 = R6 = 49.9k, R5 = 75k R7 = 220ohm, 0805, 5%

Vin is designed for a 5.5mm DC barrel jack like this one.

The USB jack is a common USB-A female through-hole plug.

This board has been tested at +5V, 1A output. The LED polarity has been reversed from what is indicated on the silkscreen.

RileyLink0.6

Breakout board for the Atmel ATTinyX4 Family of Microcontrollers - SOIC-14 Package

Breakout board for ATTinyX8 family of MCUs - QFN-32 Package

Handheld soil moisture analyzer https://github.com/ReiniervdL/Vinduino/blob/master/Vinduino-H_V3.1.ino

Remote soil moisture measurement https://github.com/ReiniervdL/Vinduino/blob/master/Vinduino-R_Wifi_V1.0.ino

Shifts I2S data for use with external filter mode on the PCM1794A

IoT RGB Lamp - https://github.com/myk3y/familamp

High speed optocoupler isolator for 3V serial port.

• 2 x Avago ACPL-M21L-SO5 optocoupler
• 4 x 470R
• 2 x 100nF

Easily runs at 1 Mbps, 2 mA LED current at 3.3V, 1 mA logic current from 3.3V

Micro add-on board for the MPU9250 9 DoF motion sensor and MS5637 altimeter to be mounted on the smd pads on the back of the Teensy 3.1. First attempt at a four layer board.

Buffer board for a Cypress FX2 EZ-USB dev board, can be used with Sigrok as a logic analyzer. https://github.com/ExplodingLemur/ezusb-logicanalyzer http://blog.explodinglemur.org/?p=37

Tube Socket Board

Simple circuit using LCM555 timer for clock to operate SN54LV163A binary 1 - 7 counter which drives FFB3904 dual mosfets that control two rgb LEDs which, lastly, cause the owl’s eyes to glow with continuously varying color. Intended as a wearable pendant for little girls and daring men. Added SMD switch for power on/off. Added rechargeable 3V, 3.4 mAH coin cell Li-ion battery and charging circuit. Removed through-hole JST connector. Added top hole for keychain.

Power a breadboard with a wall wart.

2.1mm Power Jack (TaydaElectronics.com, Part# A-4118) Double row pin header (Tayda, Part# A-198) 2 position screw terminal (Mouser.com, Part# 538-39880-0302). The screw terminal can also be had cheaper at Tayda, but I wanted it in black to match the 2.1mm jack.

Those 9 volt snaps always seem to have stranded wire leads, making them hard to plug into a breadboard. Tinning the leads can make them too thick to fit.. With this you can just plug the 9 volt snap leads into the screw terminal and call it a day. Or just plug a wall wart into the 2.1mm jack instead.

NOTE: Although you see holes, the 2.1mm jack holes are actually slots, so they work with normal “solder lug” style jack slots when fabricated (notice the rectangular outlines there). You do NOT need a jack with PCB pins.