iceRadio SDR project

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.


The C and Verilog source code is available on GitHub:


iceRadio SDR project

Dock for Onion Omega2

Valerio Backslashnew has designed a small dock for the Onion Omega 2 and 2+:


My Omega 2/2+ dock\new

I needed the smallest dock i could do, that featured:

  • Ethernet
  • Type A USB host
  • Micro USB for power

Here’s what i came up with, i called it dock\new.


It has an onboard linear voltage regulation (i didn’t bother going with a switching one for such low power), magnetics integrated in the RJ45 connector to save space, USB host ESD protection (diode array), USB host PTC fuse.

On the left side there is the RJ45 connector and nothing on the back side of the board, so that you can easily access the MicroSD card on the Omega 2+.

On the right side (the antenna side of the omega) you have the USB type A connector, facing outwards, and the microusb connector for power, facing inwards.

The project is open source (CC-BY-SA 4.0), and the KiCad schematics, board layout and the other files are available on GitHub:



5N44P has shared the board on OSH Park:


Order from OSH Park

Dock for Onion Omega2

reDot Smart 5×7 LED Matrix

Alex on is working on a smart miniature (DIP6) 5×7 LED Matrix:



This project is based on my #reDOT project. Basicly it is a 5×7 SMD LED Matrix an a microcontroller on one PCB. I started wirh 0201 LEDs (see first project log), but this was not reliable. So a second version with 0402 is in development. 0402 LEDs do have some benefits over 0201:

  • bigger and you can solder them better
  • cheaper
  • more colors availible

The microcontroller (a low coast STM8) drives all LEDs directly with multiplexing. For controlling a UART interface is available. The dimensions are like a DIP-6 package. For easy connection of multiple PCBs, the pads are castellated. Also the supply rails are available on both sides. So multiple of these display can be soldered together to a bigger display without the need of additional wiring.

reDot Smart 5×7 LED Matrix

LED ring

Jens Hauke designed this charlieplexed 20 LED blinker controlled by an ATTiny45 for the Hackaday Coin Cell Challenge:


LED Ring

This is a small blinky with 20 LEDs powered by one CR2032 coin cell
and with an ATTiny45 brain. The firmware is written in plain C and
compiled with the avr-gcc toolchain. The PCB is a two layer design made
with KiCad.
Space efficient daisychained LED placing with shared anode/cathode soldering pads.

Firmware and gerbers are available on GitHub:



Jens has shared the board on OSH Park:

LED 20 Ring ATTiny


Order from OSH Park

Here is a video of the LED in action:

LED ring


A holiday project by Dan Hienzsch (@rheingoldheavy) to build a little Snowbot with an adjustable speed larson scanner for an eye:


Snowbot V1.0

The Snowbot has three major subsystems: Power and Timer and Display.

Power Subsystem

The power subsystem uses a 3.7V LiPO battery boosted to 5V with an SC4503 boost converter to power the fully analog circuit. It requires a set of passive components in order to generate the higher voltage.


Timer Subsystem

The timer subsystem is comprised of a 555 IC that generates a clock signal. The speed of the clock is adjusted by twisting the potentiometer (the nose of the snowbot). The clock signal ticks through the outputs of a CD4017 decade counter, lighting each LED in sequence, then moving back through them again.


Display Subsystem

The display subsystem involves taking the output of the CD4017, and directing it to six red LEDs in the form of a larson scanner. In addition to lighting the LED, the current also charges a 22uF capacitor through a diode. When the output moves to the next LED, the cap discharges through a 2.2K resistor (part of a resistor network), fading the LED out gracefully.


1bitsy and Black Magic Probe

The 1bitsy and Black Magic Probe are now available in our store:


1Bitsy STM32F415 Development Board

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


Black Magic Probe V2.1

Plug and Play JTAG/SWD USB programmer and debugger with a built in GDB server and TTL level UART to USB adapter.



1bitsy and Black Magic Probe

How Fast is Your Fidget Spinner?

From Ken Olsen of The Maker’s Box:

How Fast is Your Fidget Spinner?

You never know what people will do with your ideas, and it is always fun to see someone do something I would have never thought off with them.  I got a video from someone who built my Programmable Fidget Spinner, and used a leaf blower to see how fast they could get it to go.  Fortunately, they were wearing safety glasses, and no, it didn’t come flying apart.  It did, however, start displaying erratically at about 3600 RPM (the fastest I can get it by hand is just under 2000 RPM).

So, what is going on?  TLDR: I figured it out and fixed it, and here is proof.

How Fast is Your Fidget Spinner?