ESP32 NTP OLED clock

@ build a OLED display NTP clock and document his process on his blog:

As a first project with my new ESP32 module with OLED display I chose to build OLED clock. I thought I’ll just find some existing code, upload it and it’s done. There are a few such projects for ESP8266 in NodeMCU. So I started with NodeMCU upload.

ESP32 NTP OLED clock – [Link]

8 Digit Numerical 7 Segment SPI Display Shield for Arduino UNO

8 Digit serial numerical display shield for Arduino has been designed for various applications like digital clock, stop watch, score display, temperature meter, frequency counter, digital meters etc. The circuit uses popular MAX7219 IC and two common cathode 0.5inch red seven segment displays. The MAX7219 is a compact, serial input/output common-cathode display drivers that interface Arduino UNO to 7-segment numeric LED displays of up to 8 digits. Included on-chip are a BCD code-B decoder, multiplex scan circuitry, segment and digit drivers, and an 8×8 static RAM that stores each digit. Only one external resistor R1 provided to set the segment current for all LEDs. A convenient 3-wire serial interface connects to all Arduino UNO. Individual digits may be addressed and updated without rewriting the entire display. The MAX7219 also allows the user to select code-B decoding or no-decode for each digit. The devices include a 150µA low-power shutdown mode, analog and digital brightness control, a scan-limit register that allows the user to display from 1 to 8 digits, and a test mode that forces all LEDs on. The project works with 5V DC and SPI interface connected to Arduino Digital pins D4, D5 and D6.

8 Digit Numerical 7 Segment SPI Display Shield for Arduino UNO – [Link]

Homemade 6 GHz FMCW radar

Henrik Forstén has a nice build log on his newest version of this homemade 6 GHz FMCW radar:

Frequency Modulated Continuous Wave (FMCW) radar works by transmitting a chirp which frequency changes linearly with time. This chirp is then radiated with the antenna, reflected from the target and is received by the receiving antenna. On the reception side the received signal that was delayed and undelayed copy of the transmitted chirp are mixed (multiplied) together.

Homemade 6 GHz FMCW radar – [Link]

4chord MIDI Plays All the Hits

4chord MIDI – the USB MIDI keyboard to play every major hit pop song with four little buttons. by Sven Gregori:

4chord MIDI – 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!

4chord MIDI Plays All the Hits – [Link]

1Bitsy ARM Cortex-M4F Dev Board

Open-Source Miniature Breadboard Friendly ARM Cortex-M4F Dev Board with 1MB Flash, 196kB RAM, 168MHz, floating point and more.

1Bitsy is a debuggable open source STM32F415 development board. Designed for beginners as well as advanced users that want more control over their embedded software by exposing the JTAG/SWD debug interface that is compatible with the Black Magic Probe JTAG/SWD debugger with built in GDB server.

1Bitsy ARM Cortex-M4F Dev Board – [Link]

GnuBee Personal Cloud 2

The GnuBee is live on

The GnuBee Personal Cloud 2 (GB-PC2) is a network-attached storage (NAS) device specifically engineered to run free, libre, open source software (FLOSS). The GB-PC2 has all the functionality of any commercial, proprietary NAS, but at a much lower cost and with the transparency, reliability, and accessibility advantages that come with using FLOSS.

GnuBee Personal Cloud 2 – [Link]

Arduino Weather Station With E-Ink Display

Arduino Uno home weather station with e-ink display The hardware used for this project is:

  • Waveshare 4.3 e-ink display
  • Arduino Uno
  • Adafruit BME280 combined temperature, humidy and atmospheric pressure
  • DS3231 based hardware clock

Arduino Weather Station With E-Ink Display – [Link]

Researchers Developed Highly Durable Washable And Stretchable Solar Cells

Scientists of Japanese research institute RIKEN and the University of Tokyo have successfully developed a product that allows solar cells to continue to provide solar power after being washed, stretched and compressed. Takao Someya of Riken Center for Emergent Matter Science, a designated national R&D Institute in Japan, led the research team.

Washable and stretchable solar cell
Washable and stretchable solar cell

The research results were published in the journal Nature Energy and illustrated a photovoltaic material that could be used to make washable outer garments and wearable devices. The researchers say that the innovated solar cells will be a power source to low-power devices and can also be worn concurrently. This innovation might solve one of the biggest challenges of the Internet of Things (IoT), the requirement of a reliable power source to keep all devices connected.

The newly invented solar cells could power wearable devices that include health monitors and sensors for analyzing the heartbeat and body temperature. This could make prevention and early detection of potential medical problems possible. Though the concept of wearable solar cells is not unique, the previous wearable solar cell solutions suffered from the lack of one vital property i.e. long-term stability in air and water, including resistance to deformation.

The recent stretchable solar cell innovation has successfully achieved all of the most important features and is creating the way for the top-notch quality of modern wearable technology. The material on which their new device is based on is called PNTZ4T – a highly efficient polymer solar cell capable of small photon energy loss. The scientists deposited the device onto a parylene film which was then placed onto an acrylic-based elastomer. The construction method has proved to be particularly very durable.

The device produced 7.86 milliwatts per square meter based on a sunlight simulation of 100 milliwatts per square meter before considering resistance and durability. It showed the least decrease in efficiency when soaked in the water and when stretched. The efficiency decreased by only 5.4 percent and 20 percent respectively. Kenjiro Fukuda of RIKEN Center for Emergent Matter Science said,

We were very gratified to find that our device has great environmental stability while simultaneously having a good efficiency and mechanical robustness. We very much hope that these washable, lightweight and stretchable organic photovoltaic will open a new avenue for use as a long-term power source system for wearable sensors and other devices.

ME Labs Advanced D-Stick (PIC18F47K40) released a new development board based on PIC18F47K40 PIC microcontroller. The board includes everything you need to start with your project. Documentation here:

The ME Labs Advanced D-Stick provides all the functionality of Microchip’s 40-pin PIC18F47K40 in a hardware module that includes a USB on-board programmer and virtual COM port. The D-Stick is a compact, simple and easy to use alternative to connecting a serial port, programmer, power supply, etc. to a solderless breadboard for project development. After development, simply replace the D-Stick with the pinout-compatible, production-ready PIC18F47K40.

ME Labs Advanced D-Stick (PIC18F47K40) – [Link]

STM32 Arduino Tutorial – How to use the STM32F103C8T6 board with the Arduino IDE

In this Arduino Tutorial, we are going to take a first look at the STM32 Arduino Compatible Board. This board is powerful and inexpensive. Let’s see what it has to offer!

STM32 Arduino Tutorial – How to use the STM32F103C8T6 board with the Arduino IDE – [Link]