Kris Winer designed this is a small 4-layer PCB for remote logging of absolute position and orientation:
STM32L433-based board with CAM M8Q concurrent GNSS, EM7180 + MPU9250 + MS5637 for absolute orientation, and an ESP8285 for wifi connectivity.
The absolute orientation engine uses the MPU9250 accel/gyro/magnetometer IMU sensor plus the MS5637 barometer as slaves to an EM7180 motion co-processor that sends quaternions and drift-stabilized altitude to the host via I2C.
There is an Arduino library and sketch available on GitHub:
PeskyProducts has shared the board on OSH Park:
From Kris Winer on Hackaday.io:
Small, connected device for smelling and hearing in any environment.
This is a 20 mm x 20 mm four-layer pcb tile full of interesting sensors (ICS43434 I2S Digital Microphone, MPU6500 acclerometer/gyro, BME280 pressure/temperature/humidity, and CCS811 air quality) with a Rigado BMD-350 UART BLE bridge for sending data to a smart phone all managed by a STM32L432 host MCU.
The STM32L432 is programmed using the Arduino IDE via the USB connector and serial data can be displayed on the serial monitor to verify performance and proper function, etc. But it is intended to be powered by a small 150 mAH LiPo battery for wireless sensing applications. The STM32L4 is a very low power MCU and with proper sensor and radio management it is possible to get the average power usage down to the ~100uA level, meaning a 150 mAH LiPo battery can run the device for two months on a charge.
A library for it is available on GitHub:
A collection of sketches to run the STM32L432-based (20 mm x 20 mm) sensor tile with an MPU6500 accel/gyro, ICS43434 I2S digital microphone, BME280 temperature/pressure/humidity sensor, and CCS811 air quality sensor. The sensor tile has an on-board MAX1555 LiPo battery charger, an on/off switch, and a Rigado BMD-350 nRF52 BLE module.
From Sven Gregori on Hackaday.io:
the USB MIDI keyboard dedicated to play all the four chord songs, from Adele via Green Day and Red Hot Chilli Peppers to U2 and Weezer. Thanks to MIDI, you can be any instrument – and all of them at once. Yay!
Built around an AVR ATmega328 and Objective Development’s V-USB library
, 4chord MIDI acts as a regular USB MIDI instrument. It supports playback in every key and five different playback modes:
- simple triad chord (root, third, fifth)
- triad chord + third + fifth + third as quarter notes
- triad chord + third + fifth + octave as quarter notes
- root note + third + fifth + third as quarter notes
- root note + third + fifth + octave as quarter notes
The playback tempo can be set between 60 and 240 bpm.
Here is the board in action:
The design files and source code are available on GitHub:
Sometimes you run into a few problems when developing your own hardware, and to solve these problems you have to build your own tools. This is exactly how [KC Lee]’s USB Packet Snooper was created. It’s a small device that allows for capturing and analyzing Full Speed USB traffic to debug one of [KC]’s other Hackaday…
via Hackaday Prize Entry: USB Packet Snooping — Hackaday
Rene van der Meer designed this breakout board for a bare OLED display:
I’ve been playing with cheap OLED display breakouts for years, incorporating complete boards into my projects – an easy, but bulky solution. Now that I’ve had some practice designing circuits and PCBs, it’s time for my next challenge: soldering the display FPCs directly to my own boards.
I designed this board to try out a minimal circuit before integrating it into any larger projects, and to figure out the best way to solder flexible circuits to my boards. Since all of my new microcontroller-powered board designs only require 3.3 V, I haven’t added any 5 V tolerant level shifting. What’s left is a bare minimum circuit to drive a Solomon Systech SSD1306 using SPI at 3.3 V.
golemparts has shared the board on OSH Park:
James Lewis designed this AVR based power controller for the Raspberry Pi that can safely shutdown the Pi:
The total circuit includes an AVR microcontroller, a near-zero current LDO, and a switching (buck) supply. My current design draws about 350nA when Vin is 9V. The AVR controls power to the Raspberry Pi. Two GPIO pins are used. One for the AVR to initiate a shutdown and one for Raspberry Pi to tell AVR after filesystem has been unmounted.
The design files and source are shared on GitHub: