Shared Projects

The Optical Interrupter Protoshield board the for ProMini PiDuino HAT was designed to interface two off-the-shelf optical reflective sensors to the RPi via an Arduino ProMini.

The optical reflective sensors are used to detect the presence of an object by reflecting an infrared LED back to a phototransistor. The Arduino ProMini on the PiDuino HAT will allow “real-time” sensor timing with an accuracy of +/- 4uSec, using a standard 16MHz ProMini board.

Since the interface circuit required for the Optic Interrupter is small relative to the board size needed to fit the standard Arduino Uno pinout, this board was designed as a complete prototyping shield. The two test switches for testing the interrupter inputs have been left floating with breakout pads so they can be tied to any circuit. A reset button and user defined LED have been added in addition to a power LED and D13 LED.

Since the ProMini PiDuino HAT uses standard Arduino Uno footprints, this board can also serve as a prototyping shield for other Arduino boards and/or is interchangeable with either platform.

The V+ bus is tied to the IOREF voltage, allowing operation at either 3.3v or 5v and there’s extra connection pads for all Arduino I/O pins.

The ProMini PiDuino HAT Board for the Raspberry Pi 3 allows mounting of an Arduino ProMini to a Raspberry Pi as a HAT. Functionally, this board is similar to an Alamode board but without real-time clocks, GPS interfaces, and servo breakouts that aren’t needed for most projects and it’s designed to actually fit the Pi without having to insulate things to keep it from shorting out.

The primary use is to breakout connections for I2C, both 3.3V and 5V ready, and tie the ATmega328 of the ProMini to the Pi as a coprocessor for real-time I/O processing without needing a real-time kernel on the RPi.

The ProMini can interface either via asynchronous serial or as an I2C-slave. The ProMini reset can be driven via GPIO17, allowing full Arduino programming of the ProMini directly from the RPi Host.

Three RPi GPIO’s are also broken out to direct-connect ports for use with interfacing things like single-wire hygrometers. And all GPIOs from the RPi that are used for I/O by this board are ESD protected.

It has a standard Arduino Uno R3 shield connector footprint for add-on boards.

It also supports the ID EEPROM as per HAT spec, but will work on older 26-pin RPi platforms too, sans the ID EEPROM.

The ProMini board was chosen because it’s actually more price effective than manually mounting the equivalent circuitry directly to this board. It also uses the off-the-shelf quad bi-directional logic-level converter, designed to stack above the ESD protection diodes that are mounted to this board, allowing a multilayer part configuration while keeping all parts top-side.

Happy Pi Day!

STM32L082+SX1276 (CMWX1ZZABZ-078) LoRa module development board with SMA antenna connector. Programming via USB connector with an Arduino IDE. Intended for LiPo battery-powered remote applications.

Attiny85 led love heart gift

UNTESTED - [email protected]

Recommended use of tall female/male headers (Your choice, use opposite on controller board) on the breakout PCB.

[email protected]

Tested - Works Great!

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This design is untested, but the theory is sound.

15 MHz goes in, 10 MHz comes out.

• IC1 - 74LS74D
• IC2 - 74LVC2G86
• IC3 - 74LVC2G04
• IC4 - 74LVC1G17
• R1 - 1 MΩ
• R2 - 1 kΩ
• R3 & R4 - 50 Ω
• C1 - C4 - 0.1µF
• C5 - 10 pF
• C6 & C7 - 220 pF
• C8 - 22 pF
• L1 - 1.2 µH

HDSP-K511 LED display board. Uses 7447 chip to drive two displays 1-4 selects display. This has not been tested.

IR Camera Hat with SMD

25W class D audio amplifier (24V DC)

Star Trek Communicator v2p1

Low Noise Amplifier for SDR Radio ADS-B reception Ver. 2.3 with 1090MHz ceramic-coaxial-resonator based bandpass filter, for aluminum case 25x25x80mm mount and 5 volt power. https://www.barbouri.com/2017/03/12/low-noise-amplifier-for-sdr-radio-ads-b-ver-2-3-with-1090mhz-ceramic-filter/

Commodore WiFi Modem Interface

Adds a self-biased inverter on the input and PI network LPF on the output. The input can be sine or square and the output will be ~13 dBm sine.

• IC1 - 74LS74D Dual D flip-flop
• IC2 - 74AHC1G86DBV Single 2-input XOR
• IC3 - 74LVC2G04 Single inverter
• C1-C3 - 0.1µF
• C4 - 10 pF
• R1 - 1 MΩ
• R3 & R4 - 50 Ω
• L1 - 1.2 µH
• C5 & C6 - 220 pF

Wireless PS2 controller using an ATmega32u4, nRF24l01+ radio, IMU, and batteries. This is the receiver unit that will receive the data from the PS2 controller’s tramitter unit. Rest of the project here.

Trinket Pro +OLED Display + A4988 StepStick + 4 Cherry MX switches + Home Switch. Good board to control a stepper for one axis.