Shared Projects

Holder for graphene chip and transistor mount

Holder for graphene chip and transistor mount

LCD reflow pcb

0 to 30V power supply adjustable 12A

Current Sink Or Swim (CE)

Contextual Electronics GoGoGo Motor Driver v1

Contextual Electronics GoGoGo Motor Encoder v1

AD7734_AD5764_synchronized

Dual stepper motor controller for the James Lerch Robo Foucault Mirror Tester

Here’s a parts list (you still need two motors (Jameco #155433) for the platform, video capture board, appropriate camera and a Windows (XP and Vista tested) computer with a parallel port):

1 Robo Stepper Controller Circuit Board
1  20 pin soldertail socket
1  78HCT541 (or SN74HCT541N)
12 Terminal Blocks, Dual 3.5mm pitch (may omit is soldering wires to board)
9  100k 1/4 watt resistors
8  220ohm 1/4 watt resistors
1  4.7k resistor
9  IRF540 MOSFET
1  33v Zener diode
9  1N4001 Diodes
1  LM7805 5v voltage regulator
1  1000uF 35v electrolytic capacitor
1  0.1uF ceramic capacitor
1  Red LED, 3mm
1  2x6 straight header (only needed if using external control board)

1 Power supply, 12v at least 1.5A (1A is right at the limit)
1  Parallel port cable to connect the computer to the board.
1  An appropriate project box  (An external hard drive case with built in power supply may work - check amp output)

At the lab the board’s output goes to a DB9 socket (labeled on the board) and a old serial cable is used to connect that to the motors. As long as the correct motor wire goes to the correct board output the connectors are up to you. More info about the wiring is here

Arduino Uno based rotor controller

DC rotator controller

Decodes APRS audio from your radio and sends it via bluetooth to your phone or laptop. Requires an Inland Arduino Mini Pro, and an HC-05 bluetooth card.

Monolithic Power’s MPM3620A step-down converter here configured to accept 5 - 12 V in and deliver up to 2 A of continuous load current at 5 V out. The board is designed to be mounted directly on top of the Teensy 3.1 above the USB connector, with the 5 V output from the MPM3620A powering the Teensy through VIN. There is a TI TLV70733 LDO voltage regulator which further reduces the voltage to 3V3 at up to 300 mA continuous load current. This small power management board for the Teensy 3.1 allows the powering of the Teensy 3.1, other 3V3 peripherals like sensors that might need more than the Teensy’s on-board regulator can deliver (< 100 mA), and/or power-hungry 5 V peripherals like addressable leds and motors. There is a convenient on/off slide switch which controls the MPM3620A’s enable. There is a red led which is off under normal operation and lights on pre-start, thermal limit, undervoltage and overcurrent thresholds. White circles denote GND. Corrected led circuit.

TI’s TPS61088 boost converter here configured to up-convert a one-cell LiPo battery to 4.8 V at up to 10 A. Changing a single resistor changes the output voltage from 4.8 V (300 K) to 9.6 V (600 K). On-off switch for easy power down. Intended to attach directly to a LiPo battery to allow higher motor drive voltages. Improved layout a bit.

For A1301 sensors (or similar pinout, check your datasheet), flat side of the sensor against the pcb.

Octagonal pads: +5V
Square pads: GND
Round pads: sensor data

Allows use a baofeng radio with a computer sound card. PTT via serial RTS.

It’s kind of smartwatch

Multicart for Atari2600 as built by GAMEMASTERQUILPUE. Original project from http://home.online.nl/edwin.blink/atari2600/index.htm and discussion in http://atariage.com/forums/topic/56073-cheap-2k4k-x-in-1-menu-driven-multicart-for-atari-2600/