The rayBeacon by Mike M. Volokhov is a Nordic nRF52 on-the-go development kit:
Shared Project: Raybeacon 1.4
The Raybeacon is full-featured nRF52 based wearable, ultra-low power, multiprotocol development board designed for variety of embedded applications. Due to modular design, the device can be used to build your own production-ready appliance with minimal hardware modifications.
Key features include:
- Coin sized – the board is only 25 mm in diameter
- Works from a single CR2032 / CR2025 3V button cell
- Nordic nRF52 high-end multiprotocol SoC supporting Bluetooth 5.x, Bluetooth mesh, Thread and Zigbee; of your choice:
- nRF52833: Cortex-M4F 64MHz, 512KB flash, 128KB RAM, Bluetooth® 5.1 Direction Finding, 105°C temperature qualification
- nRF52840: Cortex-M4F 64MHz, 1MB flash, 256KB RAM, Bluetooth® 5.0, ARM TrustZone® CryptoCell cryptographic unit
- Automotive grade BOM components – ready for harsh environment
- 2 x tactile buttons IP67
- 1 x RGB LED
- 1 x infrared LED (850 nm) 0402 size
- Socket for NFC flex antenna, compatible with Nordic FPC antenna and Liard 0600-00061. Can be configured as extra 2xGPIO.
- Programmable through SWD port (removable Tag-Connect socket, on-board solder pads)
- 1.27mm pitch 2×4 receptacle to connect custom extension boards:
- 6 x GPIO ports
- 1 x 12-bit ADC input
- pass-through VDD and GND pins
- 2.54mm pitch 1×8 pin header for fast breadboard prototyping; can be reused as 1.27 to 2.54 adapter
- USB interface (on-board solder pads)
- Minimal fabrication cost due to simple, two-layers only design
For detailed description, including information on custom boards and source files, please refer to the project repository on Bitbucket. Also, feel free to share your thoughts, or submit a request for a new slice or report an issue!
Alexander Rowsell writes on the Tindie blog about a DSP-based radio that can receive SSB:
Low-cost Amateur Radio SDR Receiver
As an amateur radio operator, I am always keeping an eye out for cool new radio-related things to tinker with. Hams have a long tradition of building and designing their own radios, and it’s great to see this still happening in the digital era. This DSP-based radio can receive SSB (single sideband) over almost the entire amateur HF band. This band spans from 1.9 MHz (also called 160 meters) all the way up to 28 MHz (10 meters) and everything in between.
This is a great radio for portable use. Paired with a small CW (continuous wave, the mode used for Morse code) transmitter, it would make a great QRP set for those who love low-power Morse communication. Bandwidth can be adjusted from 500Hz to 4kHz, which is perfect for CW as well as digital modes. The designer specifically designed it to be used with the extremely popular new digital mode FT-8, and it indeed fits the specifications very well. It could also be used for many other digital modes, including PSK, RTTY, JT65, and many more! The audio output can be wired directly into any PC — even a Raspberry Pi — to enable digital reception modes.
Brad Denby designed this chipsat dev board for low-power, embedded computing in space that is one of the winners of the Take Flight with Feather contest:
Chipsat development board for low-power, embedded computing in space
Junebug is a cutting-edge addition to the Feather ecosystem. It acts as a development board for chipsats – an emerging class of space system. It offers unique support for batteryless, intermittent computing. The FPU, DSP instructions, and storage space allow advanced sensor data processing with ML. Junebug is easy to manufacture, with parts selected to allow hand-assembly.
The schematic, PCB design, Gerber and Drill files, bill of materials, and other files are provided in the linked GitHub repository.
Orkhan AmirAslan on Hackaday.io has created a RAK4260 based, Feather styled LoRa dev-board:
This is a SAMR34 based LoRa dev-board with all the necessary components for fast prototyping. It’s a successor of my previous Penguino RF module and Feather breakout design ( https://www.tindie.com/products/16985/
)The new design uses the RAK4260 module from @RAKWireless and improves on some aspects, such as USB Type-C, RGB LED, user button, battery protection & voltage supervision, and optional flash & per-provisioned secure element IC pads.
About a year ago, after I first saw SAMR34 System in Package (SiP) in 2018 Electronica I couldn’t find a module for it and I took up the challenge for myself to build one myself. Then sharing first renders with the Twitterverse it gathered quite a bit of interest and I started selling couple over at my Tindie store. At the time I named the project TinyLoRa but for legal reasons I had to change it to Penguino.
- ATSAMR34J18 LoRA System-in-Package (SiP) based RAK4260
- ARM Cortex M0+ MCU & SX1276 LoRa Radio
- 256KB Flash, 40 KB RAM
- Max Tx Power: +20 dBm; Max Sensitivity: -148dBm; Rx Current: 17mA (typical)
- Frequency Range: 862 to 1020 MHz (DS values)
- Deep Sleep Current: ~1 μA (module only)
- Li-Po battery charging IC
- RGB user LED, Battery Charge Status (red) and Power (blue) (w/ cut-off jumpers)
- 3.3V low Iq LDO (~1 μA)
- Low-voltage battery cut-off supervisor IC (3V Vbat cutoff)
- USB Type-C connector with protection/filtering circuit
- 0.75 A resettable fuse
- Voltage divider for Vbat monitoring (w/ cut-off jumpers)
- SMA and u.FL antenna connectors
- 10-pin SWD programming header
- Dimensions: 2 in. x 0.9 in. (50.8 mm x 22.8 mm)
From Nisha Kumar:
An overview of the DC503 party badge as seen at DefCon 2018
Hi! My name is Nisha, and I made a party bangle for my friend, Miki, to take with her to DefCon25. It was my first fully-formed electronics project and it posed some interesting challenges due to its unusual form factor. You can read about my experiences with that project here.
Soon after DefCon25, I was approached by r00tkillah to make over a 100 of something similar for the DC503 party at DefCon26. The plan was to combine the power of the BMD-300 SoC by Rigado used in the Wagon Badge from the previous year with my Neopixel bangle form factor. We would call it “The Banglet” and it was going to be awesome.
In passive mode, the banglet’s LEDs light up when detecting nearby Bluetooth devices. The number of LEDs that are lit correspond to the number of BT devices detected and their colors are based on each device’s mac address.
Software Defined Radio (SDR) project by Eric Brombaugh:
This is a test prototype for experimenting with Software Defined Radio (SDR). It is composed of several boards that are described in detail elsewhere on this site:
Combined with suitable firmware and FPGA design, these boards comprise a receiver capable of capturing 20kHz of signal from DC to over 1GHz, demodulating it with a variety of formats and driving high-quality audio.
RF input from the antenna can optionally be tuned down from VHF/UHF frequncies to an IF frequency in the HF range before passing to the ADC.
Raw HF or downconverted VHF at an IF of 5MHz is digitized to 14-bit resolution. The maximum input signal allowed without exceeing the range of the ADC puts the 0dBfs point of this system at -10dBm in 50 ohms. The ADC runs at 40MSPS with a resolution of 10 bits, providing approximately 60dB of dynamic range and 20MHz of bandwidth which places the quantization noise floor at about -70dBm.
From the ADC, data passes into the FPGA. This is an iCE5LP4k part which provides 20 4kb RAM blocks and 4 16×16 MAC blocks which are essential for the DSP required for the downconversion. In the FPGA the ADC data is pre-processed to a sample rate appropriate for the MCU. Figure 2 below shows the primary components of the FPGA design.
It used to be something of an electronic rite of passage, the construction of an FM bug. Many of us will have taken a single RF transistor and a tiny coil of stiff wire, and with the help of a few passive components made an oscillator somewhere in the FM broadcast band.
via An Especially Tiny And Perfectly Formed FM Bug — Hackaday