DTV Tuner Breakout for SDR

Eric Brombaugh designed this breakout board for the Rafael Microelectronics R820T2 Advanced Digital TV Silicon Tuner chip:


R820T2 Breakout

This is the same chip used in most all of the RTL-SDR dongles, as well as the Airspy and numerous other radios. The chip is a versatile front-end with reasonable sensitivity and wide tuning range.


The design presented here is almost an exact implementation of the Mfg’s suggested demo design from the datasheet, implemented on the OSHpark 4-layer PCB process and provides a simple 4-pin interface with power, ground and I2C bus for controlling the tuner. A broad-band RF input and 10MHz IF output are provided on SMA connectors.

The breakout PCB design and STM32F0 firmware for the Rafael R820T2 tuner chip are shared on GitHub:

screenshot-at-2017-02-14-20-58-40 emeb/r820t2


emeb has shared project on OSH Park:

r820t2_breakout v0.1

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DTV Tuner Breakout for SDR

ISL12022M RTC breakout board

From the Pluxx’s Magitech Golem Parts Emporium blog:


ISL12022M RTC breakout board

This is a breakout board for the Intersil ISL12022M real-time clock, with optional I²C pull-ups and a CR1225 backup battery. The circuit is based on the design recommended by Intersil, with a few tweaks. It’s the second board I’ve designed so far.

golemparts has shared the project on OSH Park:

ISL12022M RTC Breakout v1.0 A


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ISL12022M RTC breakout board

Rotary Encoder Breakout Board

UPDATE: Check out the new version with pull-up resistors


I designed this simple breakout board in KiCad to make it easier to put a rotary encoder on a breadboard.   The KiCad symbol and footprint for the SparkFun rotary encoder was created by mcous on GitHub.  I used an updated version with corrected pin numbering.


Here are the rotary encoders that I’ve verified to fit:


The design files are available on GitHub:

Screenshot at 2017-02-14 20-58-40.png pdp7/rotary-encoder-breakout

The board is shared on OSH Park:

SparkFun Rotary Encoder Breadboard Adapter


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Rotary Encoder Breakout Board

STM32-F4 Discovery Breakout Board

[Written by OSH Park engineer Jenner Hanni on Wickerbox Electronics]


The STM32F4-Discovery development board has columns of male pin headers. I made a breakout board since you can’t plug the dev board into a breadboard, since the two columns on each side will short, and I’ve found the female-to-male jumpers to be unreliable. I made up a breakout board but it’s sadly cost prohibitive at $40 for three boards. Still a quick, fun project.

I’ve open sourced and shared the project at OSH Park.

I started with Jason Lopez’s STM32F4-Discovery Board Eagle schematic and footprint.

For the first test, I placed all the traces on the bottom of the board. Bottom in the layout here is blue. This made it possible to route a breakout board on the PCB router at Portland State’s Lab for Interconnected Devices. I didn’t want to have to plate all the via holes by hand to solder on the bottom and use traces on the top. Been there, done that, not interested. There are 200 vias on this board!

It worked fine, but there’s no silk and I’d really like a better looking board. I uploaded the now-verified Eagle .brd file to OSH Park. Of course, since OSH Park charges $5/square inch for three boards, it was $53.05 for three! Way out of my price budget. Luckily, you can submit designs where two completely separate boards are sitting next to each other on one .brd file.

This is the OSH preview with a cost of $33.95 for three. OSH Park charges for the smallest rectangle that encompasses your design, and you have to leave 100 mils between boards so the fab can mill it out.

It’s still significant, at about $10/board, but I can live with that. The 2×25 and 1×25 female headers also added up. Looks great, though.

The design files are available at the Github repository, and the boards can be ordered for $33.95 for a set of three from OSH Park.

I used these Sullins female headers:

Qty 4 of PPTC251LFBN-RC 1×25 0.1″ for $1.41 each
Qty 2 of SFH11-PBPC-D25-ST-BK 2×25 0.1″ for $2.89 each.

I’d bet you could search on Digikey or Mouser and find a cheaper equivalent.


This project is licensed under CERN’s Open Hardware License v1.2.

STM32-F4 Discovery Breakout Board